1、RESEARCH MEMORANDUM FRELIMINARY INVESTIGATION OF THE TRANSONIC CHARACTERISTICS OF AN NACA SUBMERGtiD INLET By John A. Axelson and Robert A. Taylor Ames Aeronautical Laboratory Moffett Field, Calif. . NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS WASHINGTON June 5, 1950 Provided by IHSNot for ResaleNo
2、reproduction or networking permitted without license from IHS-,-,-. I . r NACA RM A5OCl3 _ -. # NATIONAL ADKEORY COMMITTEE FOR AEROlDWTICS PRELIMIHARY RWEsTIGATION OF TEE TRANSONIC CEARACIERISTICS By John A. Axelson and Robert A. Taylor A preliminary inveetig%tion of m.NACA ubmerggd inlet operating
3、over a range of ma884low ratfoe and ancomfng flow angle8 was conducted throu but introducing this value in figure 8(a) has little effect on the relative values of the ram+e c every ratios for the three angles of attack. At ccmmrabls mass-flow ratios, the ram+recovery ratio decreased about 0.05 when
4、the angle of attack was increased from 0 to 4, but -roved-about 0.02 when the angle of attack was increased frcxn 4 to 8. A similar variation of ram+c%covery ratio with angle of attack was reported in figure 9 of reference 2 for the inlet fitted with amall boundary-layer deflectors shown in figure 3
5、 of refer- ence 2. . - Effect of Mach number and bump boundary layer.- The determination of ,the ram-recovery characteristics of an RACA i3ubm8rd inlet through the transonic speed rang8 tis the primary purpose of the present investigation and the reeults have been presented in fig and, second, the b
6、oundary layer that flows frm the outside surface on to the ramp by passing over the Sharp edges of the ramp wall is involved in a mixing action with higheMnergy air and SO IS less prone to separate. Pressure Distributions and Tuft Studies I . In the preceding discussian, the ram-recovery lossee w8re
7、 attributed principally to the entrance of low-nergy air fram the bump boundary layer. The bump boundary-layer parameters varied comparatively little above 0.92 Mach number; however, the ram-recovery ratios varied in the Mach number rang3 fram 0.92 to 1.15. Tuft studies, scpII8 photographs of which
8、are pre- Sented in figure 15, indicated that no si in. v (bl Me, 0.9Z Figu r 8 4. - continued . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. , , . . . PO 16 Bump chord, percent 40 45 50 55 I I l.d4 x / 1 I I /- . I / / I ” I I I Y I I I v I I /I
9、 I/ t /- II / 1 /I 1 /I 1 I InI I /I I 76 80 84 88 .92 96 IO0 104 IO8 II2 II6 I20 BUmQ station, in, v Id M, 1.12. Figure 4. - Concluded. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-22 NACA FiMACl3 2” Gieurance - 5” Clearonce .8 .6 (a) Boundary- i
10、uyer thickness. .08 .06 -08 .06 (b) Displacement Mickness. fc) Momentum fhickness. ./6 - - -.-.- 19 1 I I t I I I I I . ,L .68 .76 .84 .92 1.00 LO8 I. f6 Mach number. A4, (d) Boundary-iayer parameter #. T figure 5.- Varhfion with Moth number of. fhe bump boundary- layer choracferistics measured at 3
11、4-percent chord for two clearances between fhe bump and wind - funne/ a/. _- .- . I q .- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-RACA RM A5OCXL3 23 .86 .82 -78 p” Q a? Lzlr m. 0.57. Ram-fecovery f afio Mass-f/o w f ofio fi 1 M, i-02; W% K-g #
12、 0.80; ml m* 0.54. Figure lo.- Ram-recovery and moss-flow ConfOUB in the e?fYat?Ce of the submerged in/et, a, 0” v 27 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-28 ITACA RM A5OC13 fd) 4, 0.72; Y-4 J%Yg I 0.81; 2 m. f 0.40. ffum-recovery ratio Mu
13、ss-f/o w I utio (e) MO, i-O/; B - 4-e I 0.77; 2 m, jO.40. . Figure IO.- Continued, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. -. NACA RI4 A50213 Rum-recovery rafio Mass-flow f of/0 (9/ N, 0.76; Y-e H-p a 0.70; 0 6-P H-p t 0.76; * 0 2 o-30- Figure /O.- Concluded. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
