\jf^i\ i-ii) . i^ kCR No. L5E21 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS WARTIME REPORT ORIGINALLY ISSUED Jvine I9U5 as Advance Confidential Report L5E21 COMPLETED TABULATIOH IH THE UHITED STAOIS OF TESTS OF 24 AIRF0II5 AT HI(ffi MACH NDMBERS (Derived from Interrupted Work at Guidonia, Italy in the 1.31- ty 1.7l+-Foot Hi«h-Speed Tunnel) By Antonio Ferri Ltngley Memorial Aeronautical Latoratory Langley Fielii', Va. WASHINGTON NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were pre- viously held under a security status but are now unclassified. Some of these reports were not tech- nically edited. All have been reproduced without change in order to expedite general distribution. IU3 » DOCUMENTS DEPARTMENT Digitized by tine Internet Arcliive in 2011 witli funding from University of Florida, George A. Smathers Libraries with support from LYRASIS and the Sloan Foundation http://www.archive.org/details/completedtabulatOOunit NACA ACR No. L5E21 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS ADVANCE CONFIDENTIAL REPORT COMPLETED TABULATION IN THE UNITED STATES OP TESTS OF 2J4_ AIRFOILS AT HIGH MACH NUI'/IBERS (Derived from Interrupted liVork at Guidonia, Italy in the I.5I- by l.yij.-Foot High-Speed Tunnel) By Antonio Ferri SUMMARY Two-dimensional data for 2k airfoil sections tested in the l.Jl- by l.yk-foot high-speed tunnel at Guidonia, Italy, are presented. The test Mach numbers ranged from 0.L|.0 to 0.9^ and the test Reynolds numbers from J^OjOOO to [(.20,000. The results indicate that thickness ratio is the dominating shape parameter at very high Mach numbers and that important aerodynamic advantages are to be gained by using the thinnest possible sections. The results of preliminary'" tests made to investigate the effects of jet boundaries, Reynolds number, and humidity at very high speeds are also presented. It was found that the jet-boundary effects becaine very large at high Mach numbers v;hen models large v/ith respect to the tunnel height v;ere used. In the absence of suitable correction factors for large models it v^as considered essential to use models small enough to make the jet- boundary effects negligible. It was indicated that the data presented for the 2li. airfoils tested are essentially free from jet-boundary and hijmidity effects. INTRODUCTION The rapid increase in airplane speeds during the past 5 years has greatly accentuated the need for experimental data in the subsonic Mach number range above 0.7. Experimental aerodynamic data in this speed range, however, are still very scarce. There are tv/o principal reasons for the lack of data. First, the experimental equipment required to obtain data at high CONFIDENTIAL NACA ACR No. L5E21 p^ee.-^s on models of significant size is extremely costly t;o cjnctract and operate. Second, the problems of tech- nique Involved in obtaining data at these speeds are very complex and are not yet fully understood. The tunnel- wall-effect phenomena occurring at very high Mach nu:nbers vvlth the presence of shock v/aves become so complex that there seems little hope at present of obtaining correc- tions for these effects by analytical methods. The principal purpose of this report is to present aerodynamic data for I5 related airfoils and for 5 miscellaneous airfoils at J.lach numbers in the range 0.1^.0 to 0.9li-. The data were obtained on models of l.'^'J'^-inch and 1.965-inch chord in the I.5I- by LYi^-foot high-speed tunnel at Guidonia, Italy. Before the presentation of the test results, a description is given of the equipment used and the findings of preliminary tests made in an attempt to develop a suitable testing technique and to determine the isolated effects of such experimental varia- bles as Reynolds number, ratio of the size of the model to the size of the tunnel, and humidity. The results presented herein represent the completed part of a broad high-speed research program at Guidonia, which was interrupted by the war. I. EFFECTS OF REYITOLDS NU^/iBER, JET BOUNDARIES, AND HIMIDITY IN TESTS OP AIRFOILS AT HIGH SPEEDS A system.atic study of the effects of Reynolds number, air-stream boundaries, and humidity at high speeds was made prior to the main part of the present investigation. It is not certain, of course, that these are the only factors affecting the results, but they are considered the most important. WIND TUNNEL All the tests were made in the high-speed tunnel at Guidonia (reference 1), a single-return tunnel that could function at a pressure below atmospheric. The pressure in the test section of the tunnel could be varied from 1.0 atmosphere to 0.1 atmosphere. The tunnel had a CONFIDENTIAL NACA ACR No. L5E21 CONFIDENTIAL 5 system of refrigeration by which the temperature at low speeds could be held constant at as low a value as 15"^ Centigrade, The temperature of the air as it left the compressor was very variable, depending on the velocity and the pressure of the jet. The tunnel was powered by a JOOO-horsepower fourteen- stage axial-flow compressor, vifhich could produce a velocity ranging from O.!; to 2.9 times the speed of sound when one minimiam, retangular section of the jet I.3I by 1 .yi-i- feet in size was used. In tests at subsonic speeds the test section of the jet was kept constant at these dimensions . The jet was enclosed betv;een two straight, parallel side walls, v;hich were perpendicular to the axis of the m.odel. The jet was not restrained by top and bottom walls. (See fig. 1.) The effuser A-A was shaped in such a way as to give a uniform flow at the plane a-a. This uniform flow was attained in a series of preliminary tests by Increasing the length of the parallel-sided effuser until satisfactory flow distribution Vvfas obtained. The diffuser 3-B v-js placed in a position to give uniform flov.' ar'd to e"i,Jn-.l n?. te the vibrations that tended to occur. With the diffu'ssi'' ohope and location finally determined, the velocity was constant along the plane b-b in the test secclon of the tunnel even at the highest speeds. By varying the position and the dimensions of the diffuser a stable and uniform flow could be obtained even in the Mach nuz.iber range approaching and exceeding the speed of sound (Mach nii-.bcrs of O.9 to 1.2). The present test program included measurements made at Mach numbers up to O.9I1-. Inf orma f ion on the shape and location of the diffuser has been lost; therefore, the exact dimensions of this setup are not available. The velocity and the Mach number were determined from a tunnel calibration bas3d on measurements of the total pressure in the large section of the tunnel ahead of the entrance cone and on m'^-p&ur'ements of the static pressure at the wall near the ;!j it of the entrance cone. In order to check the ve'.oclty measured in this manner, pltot-static tubes v/ere iiistalled at the top and bottom of the jet just downstream of the exit of the entrance cone. These tubes ga-.a u qualitative indication of the jet-boundary interf e::snce erftv-'ls. Vuhen the velocities measured by these tubes wei'e appreciably different from the velocity indicated by the entrance- cone pressure CONFIDENTIAL CONFIDENTIAL NACA ACR No. L5E21 calibration, it was u.sually found that the interference effects were so large that they appreciably altered the aerodynamic characteristics of the test models. No data were taken when this condition existed. EFFECT OF REYNOLDS F.H^BER AND AIR-STREM BOUNDARIES Experimental methods .- In the study of Reynolds number effects at high speed, preliminary tests were made first on cylinders and spheres of various dimensions (reference 2). An analogous series of preliminary tests was then made for airfoils. Models of airfoils of con- stant profile but of varying chord were tested. For the study of the effect of the air-stream boundaries, tests were made with varying ratio of model chord to tunnel height over a range of Llach numbers. The ratios used were: O.O755, 0.091,2, O.II5, and O.151. The Reynolds number at each Llach number was held approxi- mately constant by varying the density. Test models .- A profile v/as chosen having an arc for the upper surface and a straight line for the lower surface because this profile could be exactly reproduced, in various sizes. The rooer surface could be made by use of a lathe and the lower surface could be formed by use of a shaper. The leading edge and the trailing edge were sharp. The maximiurn thickness chosen was 8 percent, and the profile was designated C-8 (fig. 2). Four models were constructed with such a profile; three with chords of 1.575, I-969, and 2.562 inches (k, 5, and 6 cm) for force tests and one with a chord of 5 -15 inches (8 cm) for determining the pressure distribution along the pro- file. Tests and results .- At Mach numbers of O.I4., 0.5> 0.6, 0.7, O.b, and O.Q, the lift coefficient, the drag coefficient, and the pitching-moment coefficient about the quarter- chord point of the airfoil were determined for the three profiles having chords of I.575, I.969, and 2.562 inches. All the models were tested at two Reynolds n'jmbers: approximately 250,000 and 14.80,000. The model with the 1.575-inch chord was also tested at a Reynolds niimber of 150,000. For the profile having a chord of 5 '15 inches, pressure readings were made at angles of attack between -5-5'^ and [|-.5^^ for Mach numbers CONFIDENTIAL NACA ACR No. L5E21 CONFIDENTIAL 5 of approximately O.7.. 0.3, and 0.9. Values of lift and of Ditching moment were obtained from the pressure distri- butions. Force-test results are shown in figures 5 to 8 . In figures 9 to 11 the results of pressure measurements are presented. Figure 12 shows the results obtained from integration of the pressure diagrams compared with the results obtained by use of the balance. Reynolds number effects .- The results of the pre- ILminary tests of cylinders and spheres showed that for the range of Reynolds numbers covered in the tests the effect of Reynolds number decreased as the velocity increased. At Mach numbers close to 1.0 there was vir- tually no Reynolds number effect. In the airfoil tests the importance of Reynolds number was considerable at low Mach numbers and the effect of Reynolds number was noted up to the critical Mach numbers at which the phe- nomenon of shock began to appear (figs. J to 6). For supercritical Mach numbers, the effect of Reynolds number became less until it virtually disappeared for Mach num- bers very near 1.0. In this range the formation of shock waves seems to control the aerodynamic phenomena and the development of the boundary layer. The boundary- layer thickness probably depends to a large extent on the angle of deviation of the air as it passes through the shock wave. The friction drag is a reduced part of the total drag and, therefore, the Reynolds number effect is small. The Reynolds number, however, could have an effect on the characteristics of the shock wave itself thorough its action on the boundary layer, but such an effect is not indicated. In general, these airfoil test results con- firmed the results of the sphere tests. Large-scale tunnel tests made at the Deutsche Versuchsanstalt fur Luftfahrt (the DVL) In Germany and flight tests made at various times showed similar results. Effect of air-stream boundaries .- The jet -boundary effects for the ratios of chord to jet height of 0.0755 to 0.115 covered in these tests appear to be negligible. Essentially equivalent results were obtained at a given Reynolds number for all values of the ratios employed in the tests. For a larger jet-boundary effect, a test was made of the model with a chord of 5-15 inches for which the ratio of the chord of the model to the height of the air stream (O.15I) is twice that normally used in the tests. From the results of integration (fig. 12) the values obtained for Cl and Cm /i are seen to CONFIDENTIAL CONFIDENTIAL NACA ACR No. L5E21 coincide at high Mach numbers with the values found by the force tests. This agreement indicates that the boundaries of the air stream probably did not interfere appreciably with the distribution of the pressures. For a Mach number of 0.9!^- the effect of the air-stream boundaries is important for the model of 5'15-irich chord but is not important for the models of 1.575- '^^^ 1.969-inch chord. For higher Mach numbers the boundaries also affected the results obtained with the two smaller models . It is interesting to note that the phenomenon of choking of the air stream, which occurs in closed-throat wind tunnels at high speeds (reference 3). did not occur in the tunnel in which the present tests were made. For example, for model C-6, which had a chord of 3 '15 inches, it is estimated that choking in a closed-tliroat tunnel would occur at a Mach number of 0.88 or lower. The choking Mach number for the 2 . 552-inch- chord model is estim.ated to be 0.90 o^ lower. These choking Mach num- bers were calculated from one-dimensional theory for the zero-lift condition. They are therefore somev.'hat higher than the choking Mach numbers that would actually be obtained, especially for angles of attack other than that for zero lift. In the present tests it was possible to obtain data for these models at Mach numbers as high as 0.9^1, and the results of the jet-boundary-effect tests indicate that the data are essentially free from tunnel- wall effects at this Mach number. EFFECT OF HUMIDITY AND CONDENSATION The air becomes very cold in the expansion that occurs in the tunnel at high speeds. (The process is very nearly adiabatic.) Total condensation may occur in the whole jet at high speeds if the ce-w point is passed. Even if condensation does not occur in the jet, there is a Dosslbility of its occurring in the lov/ pressure regions over the test model v\rhere an additional expansion and temperature drop occur. Very low local temperatures, which are usually smialler than the local dew point, are found at high subsonic speeds; local condensation there- fore could occur and could produce a "condensation shock" or a localized region in which condensation occurs. CONFIDENTIAL NACA ACR No. L5E21 CONFIDENTIAL Condensation complicates and modifies the flow over the body because it alters the values of the temperature, the pressure, and the speed in the air stream and, hence, modii'ies the values of the resultant aerodynamic forces. A complete examination of the effects of the phenomenon of condensation shock is very complicated. The variables involved include the value of the local humidity ^ the speed of the condensation, the possibility of the exist- ence of supersaturated air, and the scale of the model. The condensation process is not instantaneous but requires a finite time and its beginning may depend on such factors as the nuclei of condensation. (The super- saturated air may sometimes exist for a time at a tem- oerature much lower than the critical.) If the tests are made at small scale, the air can pass through the low temperature region in so short a tim.e that appreciable condensation does not occur. Condensation is therefore less likely to occur in small-scale tests than in large- scale tests. In flight, for example, when appreciable relative humidity is present, condensation normally occurs and is easily seen on propellers and wings in high-speed dives. Since the characteristics of the con- densation vary with scale, it would appear to be practi- cally impossible to simulate full-scale conditions in tests in which small models are employed. Th-e problem is further complicated because the degrees of supersaturation existing in the tests in a wind tunnel may be different from in flight and the beginning of the condensation depends on certain variable conditions of the air. The condensation characteristics of different wind tunnels, even with the same setup, have in several instances been noted to be widely different. In the subsonic tunnel of the Aerodynamlsche Versuchsanstalt (the AVA) at Gottingen, for example, it is normally necessary to dry the air before it converges in the test section to prevent con- densation; however, in the Langley 2ij.-inch high-speed tunnel, which has a comnarable entrance- cone shape and which operates under similar conditions, it is not nec- essary to dry the air, and complete condensation seldom occurs for relative humidities below 60 percent. All the test data obtained up to the present time tend to indicate that even for large-scale models the effects of humidity are of secondary importance provided that the percentage of humidity is low. in the Guidonia high-speed tur^nel previously described, it was very dif- ficult to study humidity effects because of an automatic CONFIDENTIAL 8 CONFIDENTIAL NaCA ACR No. L5H;21 crying up of the air which took place. A small quantity of water v;as removed from the tunnel air by the pump which was used to evacuate the tunnel to the low initial pres- sure. The condensation that occurred when the tunnel was started was believed to cause water to collect behind the test section and to adhere to the tunnel v/alls. As a result of this automatic water removal, fog did not occur in the test section even at supersonic velocities and no air-crying equipment v,-as necessary. Because the huanldity became less during the progress of a test in this tunnel, it vrfas impossible to give precise results as to the effect of humidity, but the general indication of the data that have been obtained was that the humidity effects were not appreciable, at least not for the small-scale models tested . Tests to study the effects of humidity have been conducted in the 8.86-foot high-speed tunnel of the DVL in Germany using an NACa 0015-6I|. airfoil section with a 1.6[}.-foot chord. In this wind tunnel the amount of condensation existing in the test section can be con- trolled by varying the cooling of the tunnel and thus regulating the temperature of the air in the test section. For very high values of relative huiriidity, it is necessary to eliminate the cooling entirely in order to raise the temperature enough to avoid condensation. The results of the humidity-effect investigation in the DVL tunnel dem- onstrated that, even for the relatively large-scale model employed, the humidity effects were of secondary impor- tance when the rela-tive humidity was small. In order to indicate the conditions under which con- densation might occur in flight, figure I3 is presented showing the local Mach number as a function of the flight Mach number for which the conditions required for satura- tion are reached. (Adiabatic expansion of the air from its static condition to the conditions corresnonding to local Mach number is assumed.) Also shov/n in figure I3 are the values of maximum local Kach number that are attained locally on two typical airfoils. The data cal- culated for the NACA 25OI5 airfoil (unpublished) were obtained from tests made in the Langley 2k-inch high- speed tunnel. The data for the NACA OOI5-6I4. airfoil were obtained from the DVL tests mentioned previously. Fig- ure 13 indicates that, even for very low values of the relative humidity, local f.^ach numbers are obtained at which condensation is possible when the flight Mach num- ber is 0.6 or greater. CONFIDENTIAL NACA ACR No. L5E21 CONFIDENTIAL The discussion in the preceding paragraphs has shown that humidity effects are likely to he most pronounced under large-scale conditions. Systematic tests to deter- mine humidity effects could best be made in a large-scale wind tunnel in which the temperature of the circulating air could be varied by regulating the cooling. The tests in such a wind tunnel could be made at various periods in order to cover a wide range of relative humidities. Fig- ure llj. has been prepared to indicate the conditions for saturation in the test section of a wind tunnel for three values of relative humidity and for various temperatures of the air in the entrance cone of the wind tunnel where the airspeed is lov/ . Also shown in figure llj. is a com- parison of the maximum local Mach numbers of the NACA ^3015 and 0015-614. airfoils as functions of the stream Mach num- ber to determine at what Mach number the conditions for saturation are locally reached. The figure shows that, for high relative humidity, it is necessary to have a high temperature of the tunnel air stream in order to elim.inate condensation in the test section. It is also shown that, even if condensation is eliminated in the test section, the necessary conditions for the formation of local condensation over the test model will normally be attained. COMPARISON OF TEST RESULTS FROM VARIOUS ' WIND TUNNELS AND FROM FLIGHT Airfoil tests .- For a thorough examination of the accuracy end signlf i cance of the test results obtained in a given wind tunnel, it is essential that the results be compared with those obtained in other \«;ind tunnels and in free flight on models of similar orofile. As a step in this direction, tests were conducted on the NACA OOI5-6I1. airfoil in both the Guidonia l.Jl- by Lylx-foot rectangular high-speed, tunnel a.nQ in the DVL 8 .86-f oot-diameter high-speed tunnel, which has closed circular walls. The model used had a rectangular plan form enclosed between two end plates. The chord of the model was 1.658 feet (50 cm), the span was L.'^ feet, and the end plates were Z^.6 by U^ .2. inches. The ratio of the model chord to the tunnel diameter was O.I85. With this setup, the choking Mach number was about 0.86, which is considerably higher than the choking Mach number that would have been obtained with the model completely CONFIDENTIAL 10 CONFIDENTIAL KACA ACR No. L5E21 spanning the tunnel jet. The data obtained in these tests consisted of pressure distributions and v/ake sur- The test conditions were adjusted to produce an equivalent relative humidity of the air of 20 percent at sea level. The Reynolds number varied v/ith the Mach num- ber from about 5,800,000 to 6,1^.00,000 in the high-speed range of the tests. The model tested at Guidonia had the same profile but was of much smaller scale, the model chord being 1.575 inches (I4. cm) and the ratio of model chord to tun- nel depth being O.O755. The relative humidity in the G'.;iconia tests was always very lov/. The Reynolds num- bers were, of course, very much lovi/er than those of. the DVL tests and varied around a value of about 500,000. Force measurements of lift, drag, and moment were made in the Guidonia tests; pressure-distribv.tion and wake- drag measurements were made in the DVL tests. The results obtained are compared in figures I5 to 17. Figure I8 shows pressure-distribution measurements made at the DVL for one angle of attack, a = -0.25°. It may be noted that the results from the two tunnels are at Variance, especially at high speeds. This lack of agree- ment indicates that the testing technique and the pro- portions of the testing system are of great importance in high-speed wind-tunnel work. The differences in the drag-coefficient values at low Mach numbers are probably due to the difference in Reynolds numbers. The largest differences between the results from the two tunnels are in the crag and pitching- moment coefficients at high Mach numbers. The abrupt changes in the coefficients from the DVL tests at Mach numbers in the vicinity of 0.8 are probably associated with the phenomenon of choking, and the results obtained in this range are therefore considered extrem-ely ques- tionable. Because of the much smaller relative size of the model in the Guidonia tests and also because of the fact that the jet was not restrained by top and bottom walls, similar effects did not occur. Further tests were made at the DVL tunnel of a sm.aller model of the same profile having a chord of Lli^B feet, the model- chord to tunnel-diameter ratio being O.15. The results obtained with the smaller model are shown in figure 16 . It will be noted that the rate of drag rise past the critical speed is appreciably less than with the larger model and C0K5TDENTIAL NACA ACR IIo. L5E21 CONFIDENTIAL 11 thus is in better agreement with the results of the Guidonia tests. Pree-flight tests were in the general research pro- gram at Guidonia, but they were Interrupted by the war. The few flijh.t tests made, however, indicated that the drag-coefficient curves had about the same slope's at supercritical speeds as were obtained in the Guidonia wi nd - tunne 1 tests. Bomb tests.- Additional comparisons between high- speed'lvTncTMluhnel and flight data were obtained in tests of an airplane bomb of conventional shape. The approxi- mate shape of the bo.ab is indicated in figures I9 and 20, which show the results of the tests. The bomb was launched in flight at an altitude of 39. '320 feet, and its trajectory as a function of tine was recorded v/ith a phototheodolite . The speed, the Mach number, the accel- eration, and the drag coefficient were obtained from the trajectory data. A one-third scale m.odel of this bomb was tested in the DVL C .66-f oot-diameter high-speed tun- nel (the ratio of bomb diameter to tunnel diameter was O.Oi!.55j niuch lower than that normally used). A one- tenth scale model of the same bomb was tested in the Guidonia I.3I- ^y l.Tii-foot rectangular high-speed tun- nel using a ratio of model diameter to air-stream height of about 0.07 lit. Similar tests vv'ere made in a wind tun- nel at the AVA in Gottingen, v^hich has a partly free air stream similar to that at Guidonia but I1.7 inches high. The size of the model used in these tests is not known, but it is believed that the ratio of model diameter to tunnel air- stream height was considerably higher than that used in the tests in the other wind tunrxels. The results shown in figure I9 indicate reasonably good agreement in the form of the drag curves obtained. As miight be expected, however, the drag-coefficient valves obtained at very high Mach numbers in the closed DVL tun- nel are higher than those found at Guidonia in the relatively unrestricted jet. The results obtained in a subsequent launching of the bomb, with reinf or comments to the tail structure, in flight tests at the DVL are shov/n in figure 20. CONFIDENTIAL 12 CONFIDENTIAL NACA hCR No. L5E21 CONCLUSIONS The following conclusions were drawn from the investi- gation of the effects of Reynolds n^opiber , air-streani boundaries, and humidity in tests of airfoils at high speeds : 1. It has been shown that the ratio of tunnel height to raodel size, the form of the test section, and the testing techjiique have a very great bearing on the results obtained at subsonic Mach numbers above O.7. 2. RejTiolds number effects were of secondary impor- tance at very high Mach numbers for the range investi- gated . 3. In the absence of suitable correction factors, the only safe experimental technique consists in keeping the scale of the raodel small enough so that the correc- tions required are negligible.. l^. In a closed air stream, the model must be small enough that the highest desired test Mach number is below the choking Mach number of the tunnel, at vi/hich the effects of the tunnel walls on the flow over the model become extremely large. 5. 3y use of a jet which is not restrained by top and bottom walls the maximum Mach number that can be used for a given value of the ratio of jet height to model chord is appreciably higher than the value that can be obtained in a closed jet. 6. The considerations of condensation phenomena that have been discussed have brought out the fact that the conditions under which condensation occurs depend on many variables and that only with great difficulty could flight conditions be simulated in wind-tunnel tests in which small-scale models are used. Wind-tunnel tests should be conducted with low values of the relative humidity, because under such conditions the effects of condensation are knovv'n to be negligibly small. CONFIDENTIAL FaCA ACR No. L5E21 ''mnFTnET-'TTAL 1 5 IT- TCST RESIT. TS W^. ?[|. AT^l^IC IN T^IF- PAGIi NinBER ??ANCtF 07 0.J.0 "^0 0,9lj. APFA^A'nrS AND MSTEODS IH'.'enty-four profiles v.'ere tested in the l.Jl Trr 1.7^--foot high-speed tunael at Guidcnia with the partly free test section previously descrihecl. For every pro- file the lift, the dra,p-, and the pitching ^.oinent at the quarter-chord point were neasured 'oj use of the three- component semiautomatic balance described in reference '4.. The extrerdties of the models were fi:ied at the balance supports, and the models v/ere checked curing the tests to verify that the aerodynaiaic loads did not bend them appreciably. All the testa were repeated v.l th the model inverted. For come models, the tests were repeated later when the static atmoapherlc conditions were completely different and with different humidities in the test sec- tion. (The values of the relative hujnidity were alwa3rs low.) The differences In the results obtained ¥'ere not appreciable . All tlie models v/ere made cf well -polished steel and had chords cf 1 R?':' '•nches for thickness ratios of 3 per- cent or ."greater.. In order to nrevent excossivo bendinp,, the models with thlc]-:ncss ratios of less than 3 percent hsd chiords of I.069 inches. The profiles of small models seldom correspond exactly w^ith the profile desired. For purposes of accu- racy, therefore, an optical device was consti'ucted that permitted photographing with extreme piecision the true section of each model on a greatly increased scale. For each model two end sections were photographed and th3 true profile was projected on the photograph to provide the desired comparison- Because the airfoils were con- structed by machine, the profile shape did not vary across the model soan. This fact v.'as confirmed by superimiposing drav/ings of the two end sections. It v cs verified that the surface was adequately sm.ooth by observing the tan- gential ill"jminated surface under great magnification. Figure 21 shows the specified shapes of the profiles tested. In figure 22 the actual shapes cf the pj-'o files tested are compared with the speclfiecl shapes. In crder CONFIT)ENTIii li; CONl'-'IDal'TIAL IIACA aCR No. V^EZl that the differenca het-.veen the sctual and tha specified proTiles nay be clearly seen, the ordinate scale used in figure 2d hss been enlarged. Trble I shows the ordinates of the profiles tested. All the tej^ts were performed at an approximately constant Reynolds number varying in the range from 3'i-'-C,000 to a2C,000. The density, and consequently the Reynolds njoinber, had to be kept low for the thinner airfoils in order to orevent excessive loads. ITRP^OILS TZSTED The profiles listed in the fcllcvidng table v.'ere tested: Airfoil Reference FA3A OC06-6k i i ITAGA C009-6ii \ NAG A OCI2-6I4 I i NAG A OOI5-6L I I KACA COO6-5I1 I NAG A OOO8-5IJ I I ITACA 0C12-?L IIACA 0006-65 j NACA 0009-63 ! NACA 2506 I NAG A 2509 NAGA 2512 5 5 5 5 5 5 5 5 6 6 o AirfD'l Reference HAG A 2515 NACA 2)406 NAGA 21^.09 NAG A 211.12 U.S.K.F.S. 1 (['. percent thick) U.S.N. P. 3 2 (8 percent thick) u.s.N.r.s, 3 QO percent thick) NAGA Ml (6 percent thick) NACA OOO6T NAGA 2509 Davis (9 percent thick) ETIi?609 6 6 6 6 7 7 7 7 6 6 (O ^Developed rt Zurich University. COFFIDEFTIAL COIffTDEKTIAL 15 RESULTS In figures 25 to I|6 the results of the tests of the 2)x airfoils are shown in the form of the usual coefii- clents: Cl o-nd Cr) are plotted against the test Mach number at the same angles of attack, and Cm„ A is plotted against the Mach number at values cf C^ oorre- sponding to the given angles of attack. figures 'i7 to 7^ shov? a, Cn, end Cm„ /I, plotted against the corre- sponding Cl for ep.ch airfoil pt the sane f/ach n^Jiinbers. In figure 71 the angle of zero lift is plotted against Mach nurr.ber for representative airfoils of the group. Figure 72 gives the riaxlmum lift-drag ratio (l'/D)inax' a for {L/L).^Q^y, and G^ ^ov ('^/'^)rr.ax ^^ functions of Mach nuxrber for all the airfoils tested. Figures 75 and 7^ present Cp^. and (L/D).-p^cLx ^^ functions of the maximum percentage thickness for all the airfoils at various Mach nnjnbers, and figures 75 ^^'^ 7^ show ClDrr* -p and (L/D)j;ip,x plotted against Mach number for several groups of airfoils having the same maximum thickness. It can be observed from the test results that ^ The lift-coefficient curve ss a function of Mach number presents a ma>:im.iara and later a miniruiti value. The Ilach numbers at these values can be defined as the first and the second critical Mach numbers for the lift. The Mach num.ber at v/hich the drag-coefficient curve abruptly bends upward is defined herein as the critical Mach number for the drag. It will be noted that the critical Mach num.bers as defined herein are different for the lift and for the drag data. The critical Mach n-'umbers used, furthorm-ore , do not necessarily correspond to the stream Mach number at which local sonic velocity is reached. The rate of drag rise past the critical Mach number increases as the lift coefficient, the angle of attack, and the thickness ratio are increased. The first critical Mach number for Cj, and the critical Mach n-amber for Cjj for each airfoil is lowered with the increase in angle of attack. CONFIDENTIAL COjWIDENTIAL NACA ACR No. L5a^i For each series of airfoils at the same angles of attack, these critical Mach numbers decrease as the thickness increases. The critical Mach numbers at the same thiotcness and the same angle of attack are much lower for the cambered profiles than for the syrnmetrical profiles tested at the same angle of attack. At equal thickness and equal camber, the critical Mach numbers are higher where the m.aximum thickness was at the IiO-pe rcent-chord station than where it was at the JO-percent-chord station. Above the critical Mach numbers, the drag increases and the lift decreases very rapidly; for a profile with a larger thickness and sharper curvature, the increase in drag and the decrease in lift is sharper. These general phenom.ena agree with results of other laboratories. (See, for example^ reference L. ) Li ft . - At subsonic Mach numbers the increase in lift coefficient with Mach number follows approximately the theoretical relation — ■ , especially for the low {l - m2 thiclOu-«JO>0 O 'H IN r\j .ClN^HVJ-jKMCM^^fNJ 1-1 r-t Q 1 1 « ^3 ryr^fnoot— mo'T.or-'^JOr- O .H^^^-iryryryry ^M o ^5 «> a at. • ab D 3 o incD inir«cMn_^o O r^ir\fj\0 in m-H o r-wN-H r-mc-incoto-^tco o\ o (M K^_a■l^Mr^o t**_d■«^<-' ■-' o o p-iry N^H^J■lnln^oso^ou^JN^r^ o s 3^ O r^ p- O ry _d-sO vD u-i_:t -^ CD w-sCO _S c o » a CTn n > 3 • feS as soco ■-< o rt o K%o ino) rfNinmo os [— osoOn-ico ^mmfMsocno-d--^ O -. ^ rH iM fM tM ry fu r\J fvl oj ^ r^ O O --1-.c^(-^fivoaMi-^jfr.fH O rH .iry M-,K-,j._^i/Mr\u~\JfO,'M ri O ii O O rH (\J -nrj (\J OCD t-sO iTUfTxry S < « a 1% sD CTsincO O OvO r-O KNOSO o ^ »-« ^ m^_*r^OsONCO mosO K^o^lnK^ O ^ rH f\J ry OJ ossOojsOrHsOcr«OjTOf«JK\rgoO ..s e a D b P 3 01 O inmrH 0.:J0 tr*r-CT\CTsO CM o O t--cM.-«COfr\Omc7sO CTsJsO-JcysO O ^ ^ fM roK^ JJJ J^K^r^, ^ o -HcMKSFr^jinmu~.^omir\j-K>r-.--(o i J. 3^ J i/s O so U-\J r- CTv ITS O OJ KMTs t\J ITN 1 f) 3S CO O OCO t^ino O O O O OsO O o so omcorHinmo ossory r-CM-O ks 0^^fMf\j»ntr\.jjj-KMr\fy >-< '-' O O Mr-.^-.cMcMcMfr.cy'M'M — ^ O P 3 OCO tX^DU^P — :tOr^Or-ir\t/Nfy_:J Si inrnKMniTij-jvo ffsinint— o O UM7s_3aJ >-< int-CT^DNO cm r-tM^*-:? O r^ r^ (M (M cm fii (M N crs*oo z « • 3| O inso o o rt KMno O u-io OCT) m osfM r-i-*fnsoa3 os|y^^-'<^a^H^so »n O i-i --^ r\J (M N rg fTify (M (\J N -lff\t-l7\0 C7sa3u^'-«ir«0sU~'O O .H -H CM (M (\l r\J K^^^J r\i f>j fM ^ « D 3 CM KSiCD O in OS p- O O fCiri o »o _d 'M CD CM (^rH K^soa^ o oco mrH inco_j O ^ ^ ry ry CM ry K^K^fM CM CM ,-. o § < « « rH IT. .f\ O u-^J O •« CT^^O O f\) ru fw CTv n • Si 3S ocO"f^ O so ^O in o ooooooooooooo a_d- O f- os-O Ory iMcOcTn D 3 ooinooofcor— in^oor-^ Ocoo so-H r^o.£DvOr--_3(jsos_jm-H>r\^ann o fTvjmso r~-co osost7M7\a) p-intrvrH CO o o o P. u ■ *-. n o ir>o\'M>o cM/NocD3oN33-3^ in^_jj-ni QcM'nJ-insOsoc— p-p-t— 'Oin^'M r-t O r-^>-^'^J^^lH^K^^<^K^M^K^«^f^^rH O § 1 * <- 3S _d- r-rH J [;- <-« JCD O OS t^ OJ l/^ 0>_d- r^ O ' rH rt .H ry fN f>i KMN -M f>j .-^ p 3| O in oooooooooooooooo ■1 y OM ooa)<-^_d--Doo«^K^so os-ho ir. [— rt _3-,o rH I3aj o oj iTN '-' ir«co in rH ^5 P 3 o t--ominoooor<>r--o o orccMin loio rnr-iso O mm o o«^ kvo-hcm t—'-t O r4 rH r^ nj nj nj K>(M cy ry --< O -< 'H fM fM friK\fnJff\frvpr,fM fM -i IT* o 4 • 3= OirifHu-xsoo (y\CT«ocoir\CTsOo- rM in fy vo u-i o O O O fM • U U m J-OCTsfMr-OOsOJOCMcD <7s*n«-« ,11 t~-(M OsincO fM (M rHcD W>t^-H inco-* Ortry Kvd-ir»j)-op-r-i--'^m_d-fM rH O ^ nj (M iTsry omosso osood r-r-i kmmoj o<-t o h w c a at. at. P 3 O mvj> p-mKMT, rH ,— CM rt mcM O irao sopnry crMnMM^KM«>o MNKNrHso p-o o --< fM «Mo p-wM:r^ i « o • It P 3 O 0s0_d_3_d-0 fM rt KNO fM O O »^ inmK-i_drM Nco "^NfMNO^o ^ •TiKAfM O (M KSir-NO P-CUQJ OsOsifi p-^o JN -H O O --.,-.,-. ry nj ry ry «n,fy fM fM ^ mooo ry moi/s o .- rvi mf- o mo o o o o o o o mo .-1 rH ry wv^ o^-o r~-CD oosO c o rnooo fMmom O-ifMinr-omoooooooomo r-i -t CM M-i_a-msO fs-tO OsOvO b: < NACA ACR No. L5E21 Fig. 1 CQ CD -,0€*3 •O ,tC*\ ii 8 O I ^ umber,R o /.575'-/V7c/7c/70rcy ZSO^ OOO E /, 9(h9 - /"%r/7 -e —^ -2. O 2. -4 6 .<2 -2 '" i^ ^ o- \ q f I i \ ( NATIONAL ADVISORY BMMinEE FOR AERONAUTIC 5 \ y CO ^FID ENT AL c m OMMir ONJL ADVISC fEE FOR AERO KY NAUTIC S k -}c/7 c^T<^rc/ 230j oao V 2.3&Z- /f^cA c/^orc/ 300,000 CONFIDENl lAL .6 tl ^'' J U^ .'^l J ^° *y- X \ A t^ rr^ K .2 Uj ^ 3?>J ^ U- p ?^ fr o r i' / -a ^ fi' ) A ? -4- .8 i-^ N •^ .a o -a -^ ./^ oa ■ o^ o Q -8 -6 -^ -2. O 2. '^ €> ( ^^ ?[ 1 f < ^b NATIONAL ADVISORY OMMITTEE FOR AERONAUTIC (,"! p CONFIDENTIAL -.3 -Z -./ O ./ .2 .3 '-At c/ioro<:.:^e^'S/-/cZ5 o/^ a C-3 o/rfo// ^ccf/on o^ A^= 0.80. NACA ACR No. L5E21 Fig. .a A/rfo,/ V 2. 362 - />7C/7 c/}orc/ 2:5'ci OOO 220^000 ■4&d, 000 300,000 \^ X \ ■4 o -.2 -.4 -6 "CONFIDE ./2 Q 04 O t04 -X)8 -4- -Z O 2 -^ & "^ 'V f ^ N \ <- ^ \ \ N ^~"irenoNsi ADvis :OMMinEE FOR AERC NAUTK S 4f.A \ CONFIDENTIAL \ 1 1 J -.3 -2 -/ O ■/ .Z .3 A^^ O. 90. NACA ACR No. L5E21 Fig. 8a Q Q \ 1 ex, g4-q' 1 /p -4 -2 - / ) ' — / / A A A r y i — ^=\ —d, \ =^ r :> o NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS frqc/re 8 . — Kj/'/oT^/on of //ff anc/ o^ra^j coe/f/c/'en'^^ ^A*7//7 A^ac/7 nc^rr>her -for a C- & o/tfi/y ^ecf/on ■ NACA ACR No. L5E21 Fig. 8b I I o -04 -08 -/2 -/6 -.20 1 1 CONFIDENTIAL 4=^. ^=' ^1 k 7^\ C ^O U' r / ^ 'i fONFipENTIAL c NATI »MMtTT 1 E ton AEBONAUn cs ,5" .6 .7 .8 /iJ Figure. 8. — Conc/udec/- NACA ACR No. L5E21 Fig. 9a-e 'V 1 1 -. ^ CONflOENral -s = -6 - -.4 - -z - - z - A 6 - .a - /.o - A- \ /< ■^ a i P / f'r ' — - - - ■/ - P \ — — -■ - — v( ^ \ / / fc } f 1 \ a \ y \ / !: / S ri \ ^ \ ^ r \ j 'b / u r — — — _ — n _ rv ^ t \\ _ 1 — 1 — , — _ _ _ _ — ^ 2 r — — r® o- D- =C pi — — ti ^ — ty — — — ■±1 Cb — p I 1 I \ c , 1 j 1 1 1 1 1 ' ' ' ' ' 1 (O) CC.45'. (b) cc.2.5' ( "" ft -a -2 o 2 .■=? .6 .a " y^ _ _. -^^ ■P -1:. ^•, /^ 'cr \, tf y / \. ^ \ / \, / h ^ ? \ ^ u_ , / -0 0- \ / (j - [rc; cc-cf^-." if- - - ^ 5 u L u u u i r — ^ n u /C w -a -2 O .2 .4- .6 a /o 1 •;- -^ ^ y- ^ i Y I >- -c ^ \ / Y :* \ / ^ \ \ V \ \ (^ ~ i>i ~c — -c i_ -0 k ' / ' / (d) oC---/.5°. _l 1 1 1 1 1 1 d 2 ^ 3 6 a 9 /a /%'/-C(S'^y' cr/>o^c/ NATIONAL ADVISORY COMWmEt fOA *fHOH»UltfS 40 GO eo /OO foraC-Q a/rfo// secf/o/o. A^ ^ O. 70 ^ a/rfo// chore/ , 3./5 /nches- NACA ACR No. L5E21 Fig. lOa-e ^ \ -/.Or — — — — — — — K — — — — — — — -^ ^ ~t s / ., 1 ^ s / \ yi ~ _ /- P ^ / -Ta >^ ' /' •y 1 n / ^ ^^ A r -o -o V- r o a / / \ \ (b) 0^2.5°. /oo 20 -^O 60 60 /or a C-d a/rfo// secf/rn. A4 = G.SO ■, -a/rfo// chore/ j 3J5 /rtchey ■ NACA ACR No. L5E21 Fig. lla-e CONflDENriAL tl -t T<^ -- i ?" r - ^ L / /^ -.4 y / f^ - e ^ / [_^ -o -o d ^ -o h- o- -y T /\ , ? ' _fa) oc.4.5°. 1 -^ -C -c — -H / ^ V / ( / (. /n' "t V ^z- , rv __ y ?^ o- 3- -C -L 1 1 -o ° / / ( / 1 1 1 1 ■ ■ r^j Gc-2.5': ,- 1 1 1 1 1 1 1 1 -/o -& -6 -A -.2 O .Z .4 .6 .fl /O 40 60 SO -c -cK^ 1 c . .1 y- ^ 1 ■o 1 7- -C -o — -a — c- . y 6 ^ /J / o / ^rr ^ / p / / / 1 / . -^ ^ 1 1 < > 1 1 / (d) cx:--/5° 1 1 1 1 1 1 1 t ^ / %■ O -e ^7 7^ & he :)r 6 -a /oo ,' ^ ^ t^- b / r \^ ^ \ O -K_ H y- J V V 1 \ / ^ ^-2 / s- ■V^ / ^^ / / >. . P u ■2 / ?- ^ / - ^ ^ 6 ^ ■t .a (e) or- -3.5' CO j CONFIOi N7W. 1 1 j_ HAItONAL ADVlSOflT MMMinEE FOR AfRONAUIICS 20 40 60 BO /OO P&rce in-/- c h o r a' F/ 9' //. F'ressu re - c//s/rijbu//or7 /T>€'o5c//'e'men'^ Tor c7 C-Q a//fo// sccf/on, M = O.SO -, a/rfo// c/7ord , 3.15 inches ■ NACA ACR No. L5E21 Fig. 12a ^-2 u QJ \ 6. -2 -.4 "/ -a -6 -"=? -2 o z ^ & /?/^^/<2 of oH-acA^, cc^ c/g^ NATIONAL ADVISORY COMMinEE FOR AERONAUTICS CONFIDENT AL -2. -/ O ./ .2 .3 C-& o/z-fo// 5ec7'-/<=>,r> -/^or- rr70c/&/s o'f "ftvo 3/ z^./>5;o -/>?c/} c/?0/ny, /^ =■ /, /OO. OOP cy {/DO/^ /'^^<'/ ouncu/yo/^ en )^ '^ ^ "O ^1 ^^ (J \ 1 \ 1 ^' ^ V. \ \ \ \ N \ \ \ \ \ N \ \ —1 \ \ \ \ \ 2 1 — z \ \ — ^ \ \ UJ \ \ \ \, Ll- z s \ \ \ \ O \ X \ \ ■^ \ \ V N \ s \ ^ V § 'I CD ^ X ? IV) X ^ (D 00 (X >^ lO C7, Vjxx aw 1 ^ (NX k^ ^^ ^uo/joss' ^s-s^ ''/c/zoc^yyo/o Joj.j3Cfotyr>c/ c/D£>^^ NACA ACR No. L5E21 Fig. 15 ^I'-^s/D'/ys'o:} NACA ACR No. L5E21 Fig. 16 .0 s 1.; ^ ^ 1 \ 0) -o _i o \ V t^ k^ % ^ Y ^ ■^n 1 r K] '■^ \ CO ! N } ^^ -5 \ ^iS L_ X \ < i [V -f. 1 — LU \ r Si LlJ Ll- i s O C_3 p ^ i ^ 3 lo fj? CI sS H' ^ J ^ i "^ q ? ^ <; 5 i n ^ i ^ ID f 9)\: ?^§.S I 1 ^Q ^^^ '^^/D/jijisoo ^^-^cy NACA ACR No. L5E21 Fig. 17a, b ^ ''^c/e^/o^/^&OD ^c/sc^o^y^ NACA ACR No. L5E21 Fig. 18a-g -.■2 -.a --4- o .4- (3 =- /i i^ ^ _ _ _ , |r= =« _ _ _ _ _. -H. \ f — ^^1^^ ^ -^ ^ t ^ •^ 1 ^ f 'aj /^' O. 74C ). I i > CONFIDENTIAL -A2 -.& O .4 .& /.Z ^' 1 ^ .n> f •*^ L 'cr 1 -^ •^ K, '(cy)/^ -0.7S0 ■s * . 'I 5 -r2 -a _< Tt r^ - -^ — — - -- - - — — A £^1 r ^^ /n I ^ j T^ * ■4 j '(b) M'0.770. i a I i \ -/ 2 -a -.4 O a .e /.z ^ u 1 1 ^ L^ — c ■^ u ^ ; ] / ^ r I H ^ 1 y '^ — - - -- — - -1 -- ■- :sj >= s^S-'H ' j {C) M - 0. 840. 20 40 60 Percent chord 8o /oo -a ^^ ^ rni ^ \-— =-1 -A i^ _ -J W _ _ _ _ ^1^ ._ _ HI 1 ^ ^ F=*, / l>«4. / T4^l / . CeJA7 '0.600.] / f ! * -/ 2. y w " L^ b= ? ^ 1=^ _J ' — ' ^*— =3 -- ^ J — -. -- _ - _ -_ — — _ /5, 7 1 1 1 1 I 1 .4 / f7^JA7 = 0.(S^7 1 .& 1 ' /.2 r ^■O 40 SO Percent chord aa /oo -/■Z 1 L- 4= ^ -a 4= r" !r= =:i -4 -^ pif— — < — - ^ _ -_ ._ _ — _ - -- _ — _ ^cr O 1 ' i J / ('cjj Af = aS5e. .a 1 p.. _. , , ^ •CQNFIDtNriAl '.Z MTIONAL AOVISDRV fOMUITUE FOR AtRONAUtlCS 20 40 60 Percent chord so /oo P/aure /8. — Pressuns. -c//5tn/Sut/c>n:> mec?5c//^e^T7en'/^:5 t^o^ on /V/9C/9 O0/d-G4 o/n/o// , CX = -0.26°, /norr? //fe lACA ACR No. L5E21 Fig. 19 '^ '^ '^ -/.'^3/D/jC/300 ^inyC7 NACA ACR No. L5E21 Fig. 20 is 'J 1 J a ^ r CO ii i « o ^ ^ ^ ^ /7 \ ^ "^-! \ V \ *) \ \ ^ v/ 1^ nl V 8 ^ ^ H ^ \ 1 I ^ •1) Q 1 '^ ■ s li //y^oD S00/5 -64 (e) AWC/? 0006-34 (f) fi/^C/)0006-34 (()) N/)Cfl OOIZ- 3< (f)) Nnc/) 0006-63 0) A/flCfl 0003-63 (j) A/flCf) 230e (A) NflC/l 2iOS Q) /^^Cf) 33/2 /O 10 10 10 10 10 10 10 '10 10 10 10 10 10 CONFIDENritL 10 10 (m) N»CP 23IS (n) NflCfl 2401c (OJ NflCfi 240S (p) Nacft 2412. (Cj) USMPS I , -^percen-t ir) U5MPS a , a percent (s) USMPS.3, /O fjercenf- - (r) NRCf) A7/ (CJJ Nf)CA 0O06 T (y) f/flCP 250S (w; Da\iis, 3 percent- m E TH360S b '^ 40 to 80 t)0 6 'ZD 40 to ^ /CO /^ercent chore/ /-^ercent chord r/<^ure -^^^ 4 CONflDENTUL ff)) mc/) 0006-63 c ) ^b 40 6'b 6o /do f-^ercent chore/ /-/a tyre. 22 ■ — /^cfc/a / a/r/oz/s festsd a 5 compared uyif/i s^ec/ /■/&<:/ 0//-/0// ■s/^a/oe'S . Orc/inafe. jco/e f/^re "f/mes c/)ora/ jca/e ^ NACA ACR No. L5E21 Fig. 22i-p 5pec/7^/ea/ airfo// CONFIOENnAl ii) Nf\Cf\ 000 S -63 (K) Nf] CA 2309 /^ ^-^^^^ 4- / \. 4 X^.^^^^-— --"^ a) Nf\Cf\ 8312 NRCP\ 83/S (n) NACA 2406 (p) NACA 24 O 9 (p) A/A CA 24 12 d to 4D S^ 5b TOO d Id 40 60 SO Tdo Perceni' c/iord riqure 22. ~ Con t/nue.d . Pe r cenf chore/ NACA ACR No. L5E21 Fig. 22q-x /Ic^ua/ airfoil Spec/ /fed airfoil ir) USN.P5. Z, 3 bercent thick (v) mCi9 2503 ^ C5)USMPS. 3, / per cent t/lick (w) £)ayis , S percent' it) mc/) M I ~Zo ^ 'ED W Too Percen/' c/iorc/ (X) FT// 3609 O ~20 40 60 60 ~^0 f-'erc ent' chord F-/ y^ 22 . — (Tonc/uded . NACA ACF. No. L5E21 Fig. 23 .3 <2 ~3 '"^ y /O NACA ACR No. L5E21 Fig. 23 Cont O ./ 3 :^ 3^ 'S T /v^6//^ 23 . — Co^7h'r?c/e qf. NACA ACR No. L5E21 Fig. 23 Cone, ./ -./ CON FIDENTIA L J-O— < MD— M3— ( HO-O o G -./ i — 'i yo~i l-EH '-^^l!)-C}-{kcH3 Q = 0.2 N Q > ./ o -,/ KW ^-<^. kU4<^ C^ -- O.J o -/ 1— tJ Pi '^^ rfWo Q =,^-^ CONFID :ntial NATIONAL ADVISOrV COMMITTEE fOR AERONAUTICS o J [* > r 1 ' ^ 7—^. H ^^- r/ q ra5 ' '-V C7 ./ .z .3 .4- .5 -G .7 .a .9 /.O fv'oL/r& 23 . — Cb/^c/c/c/ec/. NACA ACR No. L5E21 Fig. 24 .3 .4- -5 .6 .7 /-O NACA ACR No. L5E21 Fig. 24 Cont. 3 .4- .5 .6 7 .3 /^^/'ycfne 2.4- .— Ci:>r}//''^'-/&c/. NACA ACR No. L5E21 Fig. 24 Cone c .(J u -./ CONFIDENTIAL 1 --U^ KD— ' i-o Q = c / -./ rn-< L HD-1 ra. ¥^3 Q = Q, 2 o -/ , — . ><^ >-eM >^ %*~J 'oo '^~- c^ = o./ QJ I O -./ 1 u- UcK HD— I Hd^ V 1 1 'l^ Q = 0.2 o -/ - ^ r — <* *> — < \ < ^n ,-<^ yO-v ^ r^ (9 T/ NATIONAL ADVISORY COMMIHEi FOR AERONAUTKS ' CONFIDENT WL . J — ^ r-^r—l r-fi-J '-^ •~^ -^ k C^=0.4 1 ; 1 (9 ./ .a .3 .4 -5 -6 .7 .8 .3 /O F'/'gure' 2.S' . — Ct)r>c./c/c/^c/. NACA ACR No. L5E21 Fig. 26 .,£ .3 a .5 .6 .7 Q /■O tyeroafunc/m/c c/ia/'ac7^/~/j'/'/'ci$ ot^ T^e A/^C^ 00/5'-S4 cr//-/o//. NACA ACR No. L5E21 Fig. 26 Cont o ./ .3 .4 .5 .6 .7 .8 AO NACA ACR No. L5E21 Fig. 26 Cone. ./ s CONFIDENTIAl! ■.— f>< \-fy-t t>-o-< r<^ "^ 1 1 1 [ T [ S ■ [ 3 C Wt-t V-n-t f>cH r-cn ^n -■^ |)=o— C/ = a^ \ ? f -/ ^ } { ^ } { >^X 0v-^ r^ c^ = 0.4; NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS CONFIDENTIAL \> 'T \ ■''-V— jk -— — V-^ C^^ 0.5 -/ O ./ .2. .3 .4- .5 .6 7 -3 .9 /C7 /^/<^c/r-e 27. — (Oc^nc/c/c/ecy. NACA ACR No. L5E21 Fig. 28 \ a ^ .0) s .-/-/'/^c/ec/. NACA ACR No. L5E21 Fig. 28 Cone, O -./ CONFIDENTIAL ^tb-J p c \ r — T — \ y-o<. !i-o-o C^-o./ ./ -./ ^J c 1 c ' ' c r — T — ^ P""*! 1— Q-i-EHD C/ = 0. 2 1 '— 1 1 1 \ o -./ < L J 7 s i. \ i rH r^ >.^ 1 rl ^♦o o -/ , -^ Wi— J ^i— A~ -^ ,— A-' Si-^ Cj_ = o.4^ ./ o -/ CONFIDENTIAL ./ 5 ^ ^3^ /=/'^cyns 23 . — CToDc/c/o'ec/. NACA ACR No. L5E21 Fig. 29 .7 :0N "IDE^ TIAL ■6 1 N ( ) ^ 3— — ^ h ■; 1 — ^ H~^ K >" CT \ — \ 1 ^ ^ y H^-1 K /' .0 - J \ N •5 |7/f7 X 4 3 ^ - a - /■ " o ' ^ r ' ■\ "^ w r V3 ^^— ^ f\ /< U 1 /] ^ < S < r — ^ >o-< >-^ \i r-/ Lk> ./ u.^ !> \ fc' c \ [ J f rO— t j-^-. -^ k |X1-E) c ' 'i Lkr ^J^ n C ONFI DENl [IAL i-CH) C \ — I- > — \ r |>-Cr' -./ NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS c ./ .5 .^ .5 .6 .7 e 3 /O /y/^C/^ 00/e.-3^ (y/r-riy//. NACA ACR No. L5E21 Fig. 29 Cont. o ./ .2. /^'guns Z9 . — .3 .4 -5 .6 .7 .a .9 /.O NACA ACR No. L5E21 Fig. 29 Cone, ./ o c -/ CON FIDENTIAL 1 i -o^ Y ^Ha-O .0) .1) I -J r 1 r H3-( H-CH Cl = ^; 2 o -/ 1 ,—X K>^ .-<^ K>-. ~o -^ L Q = 0.3 NATIONAL ADVISORY B AFRnNAIITinS CONFIDENTIAL o -./ Ci^^o.a -z TB a ./ .2. ^'<^cyne Z9 . — .3 .4 .5 a .7 Cc>nc./cjc/&af . /.O NACA ACR No. L5E21 Fig. 30 O .3 a 5 .6 7 -3 /o oeroc/c^r)om/c c/-)afrxjc^er-/^^ycs of^ •/'■he NACA ACR No. L5E21 Fig. 30 Cont' JO .03 u^ .Oti •N \ .0 7 t.- .Q) \ .(j .06 ^ yj n5 ^ {^.04 Q .03 .02 .O/ O cot If/D ENr ML / / r [ r y / / / ■/ / / f f 1 f / r — I / ' / / f A ^ / / L 5 1 / ^ \ '-1 n? ^i y A >■ P\ Y A i 1 ^^ ^-^ j\ H ^' 'A\ / ( —-' ^ r .C^ J>< > 'M r 3 U^|J= =^ 4i U-io-H: Af^ / - -> - > — 1 AL" r" f~T NATIONAL ADVISORY . NFID ENT OMMIT TEEFO RAERQ NAUTIC s o ■3 ,n//r:>c/e" C/ ^o.^ o -/ \ . <:W ^n h rM !^-« C^ = 0.3 c -/ J ^ilJ _ i~A— ^ rA-A Q - a—< '—a K f""^ 7~v C L - 0.5 ^■v o ./ .a .3 .4- .s e .r /^ F'/'c^L^ne- 3C . — Ci::>rK:/c/<:/(Sc/. NACA ACR No. L5E21 Fig. 31 ./ .2. .3 .r>-/-/r}uec/. NACA ACR No. L5E21 Fig. 31 Cone. O Kj CONFIDENTIAL 1 1 , J ,,-f >-eH i-o~_, /K (JWi-U i^ :/ ,cr-^^ ^D— [|H>a Q) f O -/ \r^-l K-^ v> 1 H w V 1 1 o CON FIDE MTIA L COMMI TIONAL ADVISORY fTEE FOR AERONAUTICS U^-n =*-d ■"^ ^ ►^s^ c, f - O.^ J o :2 73 ^ 3 :6 ^ :6 ^ /o /^/^cjr-e. 3/. — Chnc/c^c/ec/ . NACA ACR No. L5E21 Fig. 32 .^ .3 a .5 .6 .7 /.o NACA ACR No. L5E21 Fig. 32 Cont. JO CO \|F1D LNTIAL 1 OS I y V / / t 1 r 1 i ]( Qj 1 / Jf J / 1 Q / J\ ^ j. yjl A 1 / )M A / .1 fj /J < oc / / / \J t JD5 eg ; A y A >■ 4 f m / "1 I "^ 1 U o^< V 'Ml ■=? - -3 — ^ --^ "^ ^'^ ^ { ^ M na. — ^> — ==T V U^k-M- 3 2 — . I L^ 1 - ^=H^ -^ k .0/ / \ — -Jt_ =3 ^ j» V P - y riAL NATIONAL ADVISORY | n C ONF DEN C DMMin EEFOf nm WUTIC 'o ./ .a .3 a 3 ^ :/ .8 /.O ^/c^c/re 32. . — Oor)-/7r>ciecJ • NACA ACR No. L5E21 Fig. 32 Cone. o -/ I ^ I f?^ CONFIDENTIAL ■ o -./ 1 k—LA ™-i-[]L i r^ y T rr~^ Q--^-< r^ o -./ Js A J Y-1 r'--Jvyv_i Q.b ^W.'r :^ o <0 -/ Si: O Q 1 . -^-J rt^. f~4-— ■r 1 1 '■~^ w u ^A-^ \ M^ -^ 1 1 ^ "^--LA^ ^ -/ o 1 I f — If'-— Q=£.3^ J "^ r^ r ' "i^r v •; } — — '■ b j___^ bifa* C^=c .^ "S K^ k ^ '-^a-Sl -./ o -./ .-1 — ^-4^ U-^L^ C^.o.S^ ^J ,JV^ ^ ^ [^ CON FIDE MTIA L COM MITTEE FOR AERONAL TICS \ .^= -4— y~' h^. ■ T ' hr-/t:£l~-^ c 1 — ' / \ r o •/ ^ 13 :5 ^3" :? .7 .s ^ ^^o /^/'cfure JZ. — CTo^c/tyc/ec/. NACA ACR No. L5E21 Fig. 33 /V/qc/:)^ 2309 0/>7fc/'/. NACA ACR No. L5E21 Fig. 33 Cont. o 3 . — I 1 ' f 1 1 1 o -/ L-a [ [i u 1— EH ^V Y 1 ^M ,__l 1 L, t c ^ -., lo^ < > ' — <^ > — i — < k^ ^o^ V r c 1 1 \ ,0 \ o I -aJ rK r f c^ = o: / 1 1 i^^ o -/ o — 1 — 1 — 1 ' h ■ -^ -^ --J- ^^\ r^ 1 1^1 1 1 f — 7 ' ( 1 'l ^^ ^-^ -^ "^ ^V t^-o,^^ CON FIDE ^TIA L CO VIMinEE FOR AERON WTICS (9 ■ -— ' 1 — " r — ' r — ^ i-^^-^i 1-^ rsi" "N ^^ 1 1 1 1 .- o ./ .^ .3 .4 .5 .6 .7 .3 .3 /.O ^/qQrG 33 . — Car-Ki/ucJ&c/ . i<^CA ACR r^o, I,5E21 Fig. 34 /^ Ayfac/? /7cy/mjber , /^ ^<^Q^ ACR No. I,5E21 Fig. 34 .9 /^ /Wb-cr/? ^^cv<c 4 ^ / ' , 1/ / r O . .05 1 ' ^, 3 , ^ p r t y y /^ m 2. I i i i y r / / < \~~ > < .— < yy^ r .01 ( ) C r^ r>r lENT NATIONAL ADVISORY :OMMITTEE FOR AERONAUTICS n cc )NFI[ AL o ./ .3 .'4- .5 .6 .7 .8 .9 /O AVactre. 3-^. — Cor->y/r)uec/ • NACA ACR No. L5E21 Fig. 34 Cone. O -./ COIIFIDtNllALl 1 / X\ hd-g c T T ^^ - 1^' i~o-i y^ 1 1 u^ O Q) -/ Jt\^ / ■- \~~^ <_ /_ - o -/ \ 6 — ^> — (W>~6--^ l^ h w 1 1 1 1 ^ 1 i — i — i>-^ >-A r^^ '^ / -^ -L "n^ '-V-V 1 •^ .3 .-^ .^ .6 .7 -S /.<5 A^cfa/") f7 cv , ■A ^1 J < > — ' — 1 ^ '^c:^ NATIONAL ADVISORY COMMinEE FOR AERONAUTICS ^ 1 COf ^FIDENTIi \L a -/ /^/qc^r'e 35" . — .3 -4 .5 .6 .7 a Cor-) r'-y^c/G c/ . ■ 9 lO NACA ACR No. L5E21 Fig. 35 Cone. O CONFIDEN' [IAL -- iA~o^ J c ) — c ; / y^>o r — < ' ^i^o-J^ " ./ u o 1-' 5 I 1 . c 1 — 1 3 1, r 3'"'^'^ - c - ■ r> / A. V < -' ^ ^ r ' ' 1 kv \ r ( -'L. - o ^ ! o .£rr-f \ < ^ \ \ \ ■ ^ T/ ^ o. 3 % o r-v-^ ki ^ J 1 jj ^-v-^ r-^ 1 \, 1 -/ Q - o.<^ \\ CONF DENTIAL COMMI - REE F( RAER JNAUTI ;s o ./ .^ .3 <^ .5 .e 7 & /.O ^/oc/r& 35'. — Oor-xz/c^c/e^c/. NACA ACR No. L5E21 Fig. 36 O ./ .3 . J / / ^ / .OS / J f . r 7 / .0'4 ■vV / / . /^ /I .03 1 / / ( Cc 4 3 -/ n iJ ,/ J ■^ / / .O^ L > . 1 r W\ ^ t^ F .Ol — / T Vr N=H£I^ 1 1 NATIONAL ADVISORY n CO NFID tNI AL ( mm TEEfO RAERO 1 1 NAUTK S ./ .c£ .J -^ .5" .6 .7 .S .3 /O /vyc/AS 36 . — criv^/zx^c/ec/- NACA ACR No. L5E21 Fig. 36 Cone o CONFID ENTIAL / ' < >-G-< ^-CH kJ Nr^ roo ' 1 [ -J r~* M S^K Wwj^ 1 1 1 8 <:? 1 >-^ ^ ^ Q =o.z o / . -,/ r^ -^ L A 1 1 1 J-A-J n' ^ I o './ ^ '-v. L < 1 < L ?-^^ c NATiONA COMMITTEE F ADVISORY OR AERONAUT! cs -—■ 1 T/ l,T^ ">. k - Cc = ^- -^ 1 ^^2-P' ^^. c ONF DENTIAL :> ./ / .CL _^ 3 .<2 ; 5^ .i -> '" ?■ -t 3 _ i ) /^ A^oc/7 /^c/'-^be^ ^ /l<7 /^gc/re 36 . — Ocv^c/oofe'c/. NACA ACR No. L5E21 Fig. 37 cjeKOcj/(/ric/rry/'c c ha /-Oct's/-/ s /■/c^ o-/^ -/-^-xs- NACA ACR No. L5E21 Fig. 37 Cont. o ./ .3 . < ,■ 1 ^ A ~f-^ Q=-^-2 ■ (J \ ^-1 -^ 4^ ( ^ H^4-Jv^ 1 ' \ 1 1 1 1 o -./ o -I ^ No.. < > — <^=^ M ^>-^ r^ ..^ k 1 1 1 } ■ 1 s , \ J •^-< ^-^ f " C. = o, /' , ^ , . 1 -/ - 1 ^^ ^ . — , M '-^ -„^ ,^?^ ^ C^ = a^' -./ ] '— - ' — 1 h -^^, ^^ ^-^^ v^ C^=a5 u -J — i 1 — " 1^, ^~-r r^ Nn, \, C^^o.^ S ■:> 1 1 1 1 1 NATIONAL ADVISORY CON 1 FIDE NTIA COMMITTEE FOR AERONAUTICS 1 1 1 1 1 C 1 ■/ ■c^ ) ■ V ? &r^ /V7 /7^tyne 37 . — Cjhr>c/i/c/ec/. NACA ACR No. L5E21 Fig. 38 NACA ACR No. L5E21 Fig. 38 Cont. /^^c^cvre 36 . — CTcn/Znaec/. NACA ACR No. L5E21 Fig. 38 Cone. o -./ COyPIEEN lAL .^ M L o J '—< f-O-C •-GH '■ 1 4 1 '- . o 1 f QJ O -/ U Ln c p — i ji — ^ r — ' — [ M ?-qJ 1 9 T ^f / o -/ -n-^>^^>^— ^ i r — s ! 1 > . w ^-x^' r j^oo I.I. -/ 1 ^ I ! 1 ' . '-^ ^ r N s^. O = o. 3 1 1 1 1 -/ O ./ NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS CONFIDENTIAL ^ ,^^ z' _- r-1 '-V~' J \ 1^ v^ .J .^ .5" .6 .7 .S /■O /^(^c^re^ 33 . — CIc>n<^/c/c/er-)-/-/'/-3C/S'a/ , NACA ACR No. L5E21 Fig. 39 Cone. O -.1 JON FIDENT^AL \ — \) — < > t-a—. 1 1 - C: = 1 1 C ■) ^'■^-^ L o i >U— 0— IT- 1 — i i 1 1 HT^ 1 1 c 1 ^ -1) o < \ . i Y^ , c 1 -r 1 1 l. J — < 1 — — A — ^i — i La_ ( M P 1 1 i_A-^ .^ kJ ^ i (9 -/ \ , 14 r-V—i r"^ r 1 \j -^ c L- - (0> 2 ^i ^i-, w M V. \ ■(b ? s I r ~ "1 ^ t^\ wj w h L - V, . T' . / r — F— - C 1 - D ^ t^ '-l!^! r \ I. ■ k -./ \ J - — ^ 1 — - ■ . 1 — ^' ^-^ -Star - c ~ -.o 5 NAT 3MMm Ir-'^ I>-^- ^ -2 I. - ONAI Aovisn «Y CO NFIDENT 1 AL c EE FO AERO «ut:c; o .3 x^ .5 .e .7 G .9 /(? /v^. dV^^ ^fc? . — CC'r^c/c^c/ec/. NACA ACR No. L5E21 Fig. 41 /o /^oc/ns 4-/. — £'^T^c^'/' c^ co'-r}JtDrTS^:5/b///'/'e^ 0-3 -Abe NACA ACR No. L5E21 Fig. 41 Cont. O .3 .4 5 .6 .7 /.o /^/<^c/rs 4/ . — Cctrn'-JryjeG/. NACA ACR No. L5E21 Fig, 41 Cone. O -/ COrJFID^NTAL t ^ I . J t K^ '^ T ' \ C^^O lU-^ H>-y ^.^ ^ i; -/ .^ o c ) — c p ' — i; 1 — 1^ T i >G>— . ( 1 — 1 M — 1 - (O / '"u-iHi-i! Pr T^ c -^ o 1 ^ \ ■ < ^ \ ^ ( rl [^ H \ ' L Ck> ?-. -.^ /' - r 1 = o .3 I'-a-^ U-. IrA-^ N -z v^ -/ -2 o -/ c -c - D '^ LrW— f K NA TIONAI flilViS IRV V, COMMinEE FOR AERONAUTICS '^ --P-^ ^-p-^ ^ — -C ( 1 1 \ / 1 ^. CONFI 1 DENTIAL O ./ .,£ .-3 .^ .5 .6 .7 .3 /^ Ay^Gc/-? /ycy^-y/be/^ ^ /V7 /^/^(u/-& 4-/ . — CTo/ric/cjc/ec:/- NACA ACR No. L5E21 Fig. 42 /V^^c-^ /9c/^'^yt>e/^ . A^ NACA ACR No. L5E21 Fig. 42 Cont. O .R .3 .4 .5 .6 .7 8 AO /^'aur& 42- — Cc>/7 ///0/-ye cd/. NACA ACR No. L5E21 Fig. 42 Cone o -/ CONFIDEI^IAL 1 1 } ^ rfv- \ — A_J 1 k\^ 1^1 1 I \ 7 h f \ n^ - 1 H kJ ■•-v^ 1 I.I 1 1 -— — -1 , \ 1 [ "-c»-( "~T^i H vj 7 1 1 1 1 >17 NATIONAL ADVISORY COMMinEE FOR AERONAUTICS ^ - U Hvh-' r\ •NjJ N -/ G = cS*.^ 5 \1^ CONFIDENTIAL <: :^ ./ / 'C. ■> . w ? .-<; t J • ^ ? . / 7 .<^ i c ? /< f^/<^c/r-& 4Z, — Ccyric/c/c/ec/ NACA ACR No. L5E21 Fig. 43 SO 6 ^ ■ «) .ci 5 ^ ^- a K} "k 3 \ N .3 .7^//. NACA ACR No. L5E21 Fig. 43 Cont. Q u .(b Cs Q /Oci CONFIDEN TIAL ■Uzj 08 f 1 07 1 r / ? 0& / r 05 \ V J / / \ L 1 04 A k 1 f\r CX z/e 5 4 3 2. 7/ V 7 I 1 i.t 03 {^ t '^ ^ y .'1 \M 1 ' — } u / tf . ' ' J '— " { ^ y / m / L i r — ' r^ y\ n O/ => ' ^ LO--; ^ n i T A A r b-Q— i F53>^ t 1 1 rn^i ^. CONF DENTIAL cc NATIONAL ADVISORY MMITTEE FOR AERONAUTICS ■) ,1 r ./^ ) ,^ 5 <4 5 .6 3 ■ / 7 ■t I c ) /. a A^cfC^ r^c/^-^/ber ^ A^ /^/jc/re ^^3 ■ — do^/z/^c/ec/ . NACA ACR No. L5E21 Fig. 43 Cone -./ J C( NFIj)FI^riAl[ >^ !)-o-v )-o-o Q = a / Jill Jo s .V) >I3=( fl ^^ H3-( l-Q-Q 1 1 1 1 ... f \ J T?<^<^ Q = a J II 1 1 I o / ' — , La- ■-aj s ^^v- J *- 1 , 1 -/ KATIONAL ADVISORr aWMITTIE FOR AERONAUTICS T ^ > 7— '- j; ' r ^ ^ TJi^, -^ M ■■^ i^ -.0 .>J '% cc NFIDENTIAL 3 -/ / .i£ 3 ,^ i ^ ? ^ ? .e 3 ./ 7 • i 3 e ? /. £7 y^aa/? r?cy^'>^he/^ , /W /^^cy/'^ ■^S. — CTo^c/c/c/i^c/. NACA ACR No. L5E21 Fig. 44 .3 .-a .5 .6 7 /.O NACA ACR No. L5E21 Fig. 44 Cont. ^^^c/re -4? . — <-^ r ./ T c - 1 - CD ■ ''-^v -.? I. - c [ V"- ' ■■' 1>n- r ■ "-TaTW- . ^-i- o -./ -.2 o ' k — < 1 < H r~\ r^ jjM^ (' - 1 — 1 \ — 1 2 r^ 1 > - /- — -z o I 1 ^^ ^- n ,^ -^ t^v_ H r 1 =; ^Si 1 -/ -2 ' "^ U—-,,. .-r" ^, c - - r -) <3 k. '^- NAT lONAI mm, RY -.2 O ./ .<2 CWimttE FOR AERONAUTICS CON ■IDE ^TIA - 1 ^ (" ^ V-H ^^ »t^ ^f^ c _ - /O 5 ^ ■ L ^ - C/ -^ .■=^ .d~ .6 .7 .8 /.O fv'<^cyris '44- ■ — C^o^^/c/c/&c^. NACA ACR No. L5E21 Fig. 45 .2 .3 .4- -5 .6 .7 8 /.O NACA ACR No. L5E21 Fig. 45 Cont .3 .4- .5 .6 .7 /O ''^/acy/Ts '^fT , — Cor?//^) c/Gc/ . NACA ACR No. L5E21 Fig. 45 Cone. ,/ CONFIDENT AL o \r\^ ./ 1 r -^ - c -Qj U -./ 1 c 3 r H-. r - - <^ / ^\^V /- - ./ o { > 1 S — — i s — \ \ — < Kr\ / r^ L -J c -~ --0 ^ ■-- -^- ■ ./ o ^ r^ N V (-- - <^ .3 ' -IVJ f^ "^-A L - o -./ 1 NATIONAL ADVISORY cc NFI DENT lAL CI MMinr tt hUK AERON AUIIUS ' T-f—\ '-^-^ ^ p 7 f c _ - r- ^^ v^v '—i_ - ^' ' 'J ./ / .2. 7 5 .*=; z > 5 .^ -? . / 7 -d ? C ? /. /^(C/cr/y y^cy^^>^Se/^ ^ /W 't'^' . — Co^cz/uc/ec/. NACA ACR No. L5E21 Fig. 46 /^Wctc/i '^cy^y^S er , /V7 NACA ACR No. L5E21 Fig. 46 Cont. /^i^y-e <^6. — C<=>r?7'^^cy&G^. NACA ACR No. L5E21 Fig. 46 Cone. o CONFIDENTIAL o c ) — V — 1 L v ) O.J-, ./ C- - r^ ^4^- r> ^ ( 1^ V ,0) \ ^^ 8 -/ 1 ) ( 1 L s ^ LJ H^j - P — ^ >€U i 1 Hd-:^ '^ < ^--x 'O-y L<..4H^ ^^ •O :p ^Z. o -/ -7^ o -./ 4 — -. -^ kvv- ^ "^ ■-A . ( ^ n- ■s ~ L. ■< h "v^ '-yJ ^ ^^ C, '-0.4 1 ^ ■ .1 1 ^ o -./ NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS ¥ ^ f'^s^rH ^ C^ ^o.5 1V-; -C-7 CONFIDENTIAL 3 '^ ':5 .6 .7 .« 7y /^^ ■'O ./ .£ z^/^'^^e. ■4€.— CQ/-yc/cfc/ec:/. NACA ACR No. L5E21 Fig. 47 (K ^ 8 4 o 1 0.6 5 - .70 - — .8 ■8 5 90 34- CONF 1 DENTIAL .•^' -^ - 'Cr^ ^ y .^ ^ t'' .1 08 / / / o<^ / / / / --— —•'' ./- y- > ' -- jr __^- — J E^ ^^^^^^ .2 (9 -<2 ^- — - ■-=-^ ~-^ c ONFI[ )ENTI/ \L COM NATION/i MinEE L ADVISORY OR AERONAUTICS -.a o .2 .-/&/■/ NACA ACR No. L5E21 Fig. 48 V ^ ■ yv7 1 o.es .70 30 35 30 ..9^ -.—-. 8 CONF 1 DENTIAL /? ^ V^ w^ Q ^ QJ 0^ to ./a '' y / .o& / / _ - -^ X / n<^ -'' ,' ^' o '^ o :£ CONFIDENTIAL NATIONAL ADVISORY ;OMMITTEE FOR AERONAUTICS -.a o .2. .4- ■& /.o of y^e. /V^C/^ 00/2- ^ ^ /4 y- •■ r ./e ■/ ./a ,''^ ',,- .OQ ^ ./ 04 ---' . -'' ^■ ^ . ■ -— _^^ n t ^ o -a ^ ----- NA IIONAL ADVISORY CONFIDENTIAL 1 1 , COMMI FTEE FOR AERONA yrics -.<£ .<£ .4 .6 .5 AO 0/ //7e /V'^C^ 00 /d-- 6'^ cf/r/o/A KACA ACR No. L5E21 Fig. 51 On .70 ao 35 30 8 .9: ^^> o' s*^ ^ QJ «: ^^ V u .oa y / n ^\ J , ■si- .^ - ^ ^ ^' t ^ ^s /' /' 1 / (O^ _ - - ' "-' ", y /- y 1 / / — -' ^ > <<^' n = L^^ *^ (9 -^ CONFIDENTIAL Niil'ONAL ADVISORY "COMMintE FOR AERONAUTICS " -^ (9 .2. .-a .& .3 /.O 0/ //te A//9C^ OCxDa-3^ cf/r/o^'/. NACA ACR No. L5E21 Fig. 53 - ■ / .65 ■ 70 .85 1 o .30 34 8 nr NFIDENTIA L 4 ^ x' ■ y ;.•■ ^ ^ ^ o /- ^ I? § ./^ y / y / OQ — -- /' / — -—'' y n^ /' /■ /' ^^ i: -- - - " = — — o -^ _ _^ ~ ' ~ - ^ WTIONAL ADVISO W CONFIDENl 1AL COMN (ITTEE FC R AERON AUTICS ^ .a o .a. .4 .8 /.o Z //■/■ coe ///c/e nf, C^ fvc^c/r& 5'3 . — y^eroc/cy/y a/y^/a c^Cf^cfcyey/^f/CSf of f/7& A^yjCy) 00/2~34- a/r/oy/. NACA ACR No. L5E21 Fig. 54 I ON 1 o.es - 70 - _ .80 .6 5 SO — 3a —-- -- 8 — CON ■IDENl lAL 4 .,- ^ f^, '"x' / O ■^^^ f^^' '^ Q Q ./2 .08 .04 O y' /' / 1 ^' --" ^^-' JT-*^ ■ y r-i^= fcS=^^ "^ - - £1:^^ — - -"-■— NATIONAL ADVISORY a c ONFII ENTI/ \L aiMMin EE FOR ^ ERONAUl ICS -.a o ■4 . coe///c/er?/; C^ 07^ /^ /V'^C^ 000^-e>3 o/^/o^/- NACA ACR No. L5E21 Fig. 55 00 /^ 0-65 ■ 70 QO 3 5 8 30 34 — _- — CONFIDENTIAL 1 1 4- r/r^ '' J'^'' y^. ■€ ^ ' €^^ ^ 0N\ ./a 08 y / - -■' '■ ^/ / n^ — --' /' y' 1 / ^ -<:- • y o ^-- ^^ o -^ - ~ 1 NATION IMinEE \V ADVIS FORAER ORY 3NAUTICS c 3NFID ENTIP L con -.^ o .2. .4 ■8 /■O ^L/ff coiBff/c-/e.n-t C of f/ie A//9C/9 0009-G3 a/rfo/V. NACA ACR No. L5E21 Fig. 56 8 - 4 o -^ 0.&5 .70 .60 1 .35 --- .90 — - .94 — >^>" CONFIDr ilNllAi ■ .^',<^''^^' ,,< _^ :- '"^' ^ -x'' ^ -^^ ^''' >"-;; ^ V >0 Q ./a .08 y ' \ ^^ /■ (O^ --.. ^^- — --- -— ' ^ ' / / ~ v^ - — ^ --" — ' ,, /, n ""~°^ L^^^l-: "■ '^^^-^ X -(j^ I o -^ 1 NATIONAL ADVISORY cc NF1D[ :ntiai " - — ^ --; - J :irr: -r^ii — -^ — ~~" ■ -•^ -.2 ^ .a ■4 .8 K AOA -/- J (. ;■ ■-■■■ Q -is>c>: NACA ACR No. L5E21 Fig. 57 U On 8 A o -^ /^/ 1 0.65 .70 .ao .8 5 .90 .9^ CONF IDENl "lAL /:,-- a^ - ,'^ ',-' / V / ^ • ' ^>' ' / -*^ i. • f X .y / /' ^ .^' // ^\. ^ ^^ ./2 ^6 \ ^^ ^ /' \ "^ --^- --'' /'' cfc/nar?o/C' c/?cf/'ac/T&r/s/-/cs o7^ f/?e. /y^C/9 2^oe, o/'rfo//. NACA ACR No. L5E21 Fig. 61 V (J Q ^ 8 ^ -^z ^ ' -^^^ ^^ 0^ OS*. (J Q (u. ^ O -z -.4 NATIONAL ADVISORY COMMinEE FOR AERONAUTICS ^^ ~- — - rr^ --- - ^ __ CONF DENl ■|AL -.^ -a o -^ .^ e .a Z//f Coe-f-fiC/ e nf, C^ of iVie C/S./V^S. 2 cf^rfof/. 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