1、TECHNICAL NOTE 0-363 INVESTIGATION OF THE AERODYNAMIC CHARACTERISTICS OF A COMBINATION JET-FLAP AND DEFLECTED-SLIPST-AM CONFIGURATION AT ZElRO AND LOW FORWARD SPEEDS By Kenneth P. Spreemann and Ebin E. Davenport Langley Research Center Langley Field, Va. NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
2、 WASHINGTON May 1960 PASA-%N-D-363) INVESTXGATILl LE TBB N8 9-7 G9 9 3 AEBOCYNAflIC CbASACXEblS?XCS CE A COMBINATION 3E1-F LAP AND DE however, a few significant results have been noted. Large losses in lift were encountered at low forward speeds for values obtained within ground proximity compared w
3、ith values obtained out of ground proximity. INTRODUCTION Recent investigatjons have shown that jet-flap-wing configurations at low forward speeds have provided very high lift coefficients. example, see ref. 1.) that the propeller slipstream deflected by large chord flaps can give very high lift coe
4、fficients (ref. 2). slipstream principles produce significant lift augmentation over and above the sum of the power-off lift and the vertical component of the thrust. may be useful in analyzing the manner in which these augmentations com- bine at low forward speeds and the effect of ground proximity
5、. (For Also, tests at low forward speeds have indicated Both the jet-flap and the deflected- The present investigation was undertaken to provide data that The model employed in this investigation was an unswept, untapered wing with two propellers mounted in two inboard positions on the wing. Incorpo
6、rated in the wing was a full-span blowing nozzle that ejected Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 4 air over the knee of the sliding flap at 61.5 percent of the wing chord. The data were obtained at zero and low forward speeds in and ou
7、t of ground proximity. , .+ COEFFICIENTS AND SYMBOLS I The force and moment coefficients used in this paper are based on the dynamic pressure in the slipstream. This system is employed because, when a wing is located in a propeller slipstream, large forces and moments can be produced even though the
8、 free-stream velocity decreases to zero. For this condition, coefficients based on the free-stream 2 dynamic pressure approach infinity and hence become meaningless. There- 5 L 8 fore, it appears appropriate to base the coefficients on the slipstream dynamic pressure. indicated by the use of the sub
9、script s in this paper. The relations between the thrust and dynamic pressure in the slipstream have been derived in reference 3. The more familiar coefficient forms based on the free-stream dynamic pressure can be found by dividing by (1 - CT,); The coefficients based on this dynamic pressure are .
10、 . The positive senses of forces, moments, and LL, s that is, CL = angles are indicated in figure l(a) for the static tests and in figure l(b) for the wind-tunnel tests. wing quarter-chord point. - T?s - The pitching moments are referred to the CL lift coefficient L - lift coefficient based on slips
11、tream dynamic pressure, qss CL, s cx, s bX longitudinal-force coefficient, - qss Mv -L pitching-moment coefficient, - q,sc cm, s CT TP thrust coefficient, 24 onD cT, s thrust coefficient based on slipstream dynamic pressure, T, r D2 qs 4 Provided by IHSNot for ResaleNo reproduction or networking per
12、mitted without license from IHS-,-,-3 I- CP cP F F L L FX FX M,. * -1 MY TP Q Qj vm pm P 8, 231 Qn 35 power coefficient, pmn D P - P, 9, pressure coefficient, Q-P *V qS momentum coefficient, JJj resultant force from static tests, lb resultant force from tunnel tests, lb lift from static tests, lb li
13、ft from tunnel tests, lb longitudinal force from static tests (Thrust - Drag), lb longitudinal force from tunnel tess (Thrust - Drag), lb pitarthing moment from static tests, ft-lb pitching moment from tunnel tests, ft-lb measured jet thrust from wing-flap configuration, lb propeller thrust, lb prop
14、eller shaft torque, ft-lb rate of airflow out of the jet expanded to free-stream static pressure, cu ft/sec jet exit velocity (assuming isentropic expansion from plenum chamber to free-stream static pressure), ft/sec free-stream velocity, ft/sec free-stream static pressure, lb/sq ft local static pre
15、ssure, lb/sq ft free-stream dynamic pressure, pmVm 12 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 pm b/2 C D h S X Y n U iW 0 6f T .E. P Cb r R t TP slipstream dynamic pressure, 900 + -, lb/sq ft D2 r- 4 mass density of air in free stream, slug
16、/cu ft mass density of air in jet, slugs/cu ft span of semispan wing, ft wing chord, ft propeller diameter, ft height of wing quarter chord above ground, ft semispan wing area, sq ft wing chord station measured from leading edge, ft wing spanwise station measured from root chord, ft propeller rotati
17、onal speed, rps angle of attack of wing chord plane, deg wing incidence, deg turning angle (inclination of resultant-force vector measured 1L from longitudinal-force axis), tan FXO deg flap deflection relative to wing chord plane, deg deflection of trailing-edge extension relative to flap chord plan
18、e, deg propeller blade element angle, deg propeller blade element chord, ft radius to propeller blade element, ft propeller tip radius, ft propeller blade element thickness, ft Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. I 5 MODEL AND APPARATUS
19、 A drawing and the pertinent dimensions of the model are presented in figure 2. the following table : The geometric characteristics of the model are given in Wing : . Area (semispan), sq ft 6.22 Span (semispan), ft 4.67 Chord, ft 1.33 Taper ratio 1.00 . Aspec* ratio 7.00 Airfoil section NACA 63A412
20、Propeller: Diameter, ft 1.33 Nacelle diameter, ft 0 -33 Number of blades 3 Airfoil section Clark Y Solidity 0.134 The model consisted of a semispan wing with two 1.33-foot-diameter equal to 0.25 and 0.554. A sliding flap was i300-MPH 7- by 10-foot tunnel, upstream of the regular test section. ment a
21、nd calibration of this section are given in the appendix of reference 2. The investigations reported in As a result, the l7-foot The arrange- The tests were run at various free-stream dynamic pressures and propeller thrusts so selected as to maintain a dynamic pressure of 8.0 lb/sq ft in the slipstr
22、eam. also made at a free-stream dynamic pressure of 8.0 lb/sq ft. of the propellers was held constant throughout the angle-of-attack range. The tests with the propeller off were The thrust Corrections to the free-stream velocity due to blockage and slip- stream contraction were estimated and found t
23、o be negligible. boundary corrections applied to the angle of attack and the longitudinal force were estimated for a square test section by a method similar to that of reference 5. culation about the wing, it was necessary to subtract the direct thrust contribution of the propeller and jet to the li
24、ft before applying them. The jet- Inasmuch as these corrections depend on the cir- The following relations were used: where ACL is the increment of lift coefficient approximately propor- tional to the circulation and is obtained by subtracting the direct thrust contribution as follows : F3 + 8 2 5 4
25、 * Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-“ t. 6 e 9.t 7 L 2 5 a d . where Fp - and 8, are the thrust recovery factor and turning angle TP obtained with propeller thrust at zero forward speed and Oj and Fj - Tj are the turning angle and thru
26、st recovery factor with the blowing nozzle at zero forward speed. PRESENTATION OF RESULTS Forces, moments, and turning angles at various flap angles are pre- sented for the static condition out of ground proximity in figure 6. Force and moment coefficients for the various configurations tested in th
27、e tunnel in and out of ground proximity are presented in figures 7 and 8 and the (a) parts of figures 9, 10, 12, and 13. Propeller coef- ficients are given in the (b) parts of figures 9, 10, 12, and 13. sure coefficients over the wing leading edge are given in figure 6(e) for the static condition an
28、d in parts (c) of figures 9 and 12 at low forward speeds for a limited number of configurations and momentum coefficients. Pres- rm ine results f the imestigntion a.re presented in the following detailed listing of the data figures: Figure 6 Slipstream deflection data, static Forward speed data, tun
29、nel: . 7 6f=oo 8 10 Effect of propeller thrust on aerodynamic characteristics with model Power-off characteristics Effect of propeller thrust on aerodynamic characteristics with model out of ground proximity at - 6f=40 9 6f = 40; 6T.E. = 40 6f = 40; iTaE = 60 11 tif=4O O 12 . . within ground proximi
30、ty at - . if = 40; 6T,E = 60 13 Summary of comparison of lift coefficients in and out of ground proximity: 6f=400 14 6f = 40; tjTmE = 60 15 . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-8 DISCUSSION In all figures in which the longitudinal-force
31、coefficients appear, = 0 indicates steady level flight, negative values of indi- indi- cate decelerating or gliding flight, and positive values of cate accelerating or climbing flight. without analysis; however, a few significant results of the investiga- tion should be noted. CX, The data are prese
32、nted herein A comparison of the lift for steady level flight (CL, at CX, = 0) 8 out of ground proximity (figs. 9 and 11) with that obtained within ground proximity (figs. 12 and 13) is presented in figures 14 and 15. 2 3 From these figures it is seen that for values obtained within ground proximity,
33、 compared with values obtained out of ground proximity, large losses in lift were encountered at low forward speeds. However, in the higher speed range low momentum coefficients, Cp,s 0.1. forward speeds on a plain jet-flap model (i.e., without propellers) have been reported in reference 6. CT,s = 0
34、.6 only small losses were observed at the Similar ground effects at low One concept of a jet-flap configuration involves mounting a large number of jet engines in the wing with their inlets at the wing leading edge. Pressure distributions around the wing leading edge were taken in order to provide s
35、ome information on the airflow within which such inlets ilay iiage to operate. From this investigation it is shown that for the range of variables tested (i .e., angle of attack, momentum coefficient, and spanwise location behind the propeller), there was considerable variation in the location of th
36、e wing leading-edge stagna- tion point and peak pressure coefficients. Langley Research Center, National Aeronautics and Space Administration, Langley Field, Va., January 19, 1960. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-9 REFERENCES 1. Lockw
37、ood, Vernard E., Turner, Thomas R., and Riebe, John M.: Wind- Tunnel Investigation of Jet-Augmented Flaps on a Rectangular Wing to High Momentum Coefficients. NACA TN 3865, 1956. 2. Kuhn, Richard E., and Hayes, William C., Jr.: Wind-Tunnel Investiga- tion of Longitudinal Aerodynamic Characteristics
38、of Three Propeller- Driven VTOL Configurations in the Transition Speed Range, Including Effects of Ground Proximity. NASA TN D-55, 1960. 3. Kuhn, Richard E., and Draper, John W.: Investigation of the Aero- dynamic Characteristics of a Model Wing-Propeller Combination and of the Wing and Propeller Se
39、parately at Angles of Attack up to go. NACA Rep. 1263, 1936. (Supersedes NACA TN 3304 by Draper and KUhn.) 4. Kuhn, Richard E., and Hayes, William C., Jr.: Wind-Tunnel Investiga- tion of Effect of Propeller Slipstreams on Aerodynamic Characteris- tics of a Wing Equipped With a 50-Percent-Chord Slidi
40、ng Flap and a 30-Percent-Chord Slotted Flap. NACA TN 3918, lB7. 5. Gillis, Clarence L., Polhamus, Edward C.) and Gray, Joseph L., Jr.: Charts for Determining Jet-%mdaq Corrections for Complete Models in 7- by 10-Foot Closed Rectangular Wind Tunnels. (Formerly NACA ARR L5G31. ) NACA WR L-123, 1945. I
41、 6. Vogler, Raymond D., and Turner, Thomas R. : Wind-Tunnel Investigation NACA TN 4116, 1957. at Low Speeds To Determine Flow-Field Characteristics and Ground Influence on a Model With Jet-Augnented Flaps. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-
42、,-,-10 m a) m aJ 0 k 0 k % 0 I I rl a, k a aJ m 3 .d Fr -. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-11 J Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-12 i I Figure 2.- Drawing of model. (All
43、 dimensions in inches.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-T; - Upper surface Typical cross section with chordwise locations .I43 ,179 .i I I Q .2 s .3. Inboard nacelle ? .2 7 1 J Sp an wise s tot ions Figure 3.- Location of pressure ori
44、fices. (All dimensions in inches.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-14 (a) Three-quarter front view. L-5 7-2826 Figure 4.- Photograph of model in tunnel with ground board installed. 6f = 40; 6T.E = 60. Provided by IHSNot for ResaleNo r
45、eproduction or networking permitted without license from IHS-,-,-. n (b) Three-quarter rear view. Figure 4. - Concluded. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-16 Figure 5.- Physical characteristics of 1.33-foot-diameter propeller employing
46、Clark Y airfoil section. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. CAS (a) Pitching moment. G.,S (5) Ratio of resultant force to thrust. 8 .2 .4 .6 .8 LO I2 c, ,s (e) Turning angle. Figure 6.- Effects of variations in momentum coefficient on
47、the aero- dynamic characteristics out of ground proximity with and without trailing-edge extensions. CT,s = 1.0; g, = 0. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-18 0 0 A .8 .6 L .2 7-p 5 (d) Summary of turning effectiveness. Figure 6.- Contin
48、ued. None 40 60 t 0 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. -2 i -2 - 2 179 CP 0 r7 143 C, I- 0 Upper surface -Lower wrfoce -. -._ I= j:,. I */c x/c K/C X/C c,* = 25 c, = 49 c, = 77 0 IO 20 0 IO 20 0 IO 20 0 IO 20 c Provided by IHSNot for ResaleNo reproduction or networking permitted without licens
