On the aerodynamic characteristics of thin slab delta wings at hypersonic speeds - part 2: effect of wing geometry

We report our findings on the aerodynamic characteristics of thin slab delt a wings at hypersonic speeds. We have tested wings with three sweeps (76 de grees ,70 degrees and 65 degrees) and four t/c ratios (0.04, 0.053, 0.06g a nd 0.10) usings a special thin three-component balance. To date, the wing w ith t/c of 0.040 is the thinnest wing ever tested without lee-side body at any hypersonic Mach number. The study was carried out at Mach number of 8.2 , Reynolds number of 2.13 x 10(6) and incidence of -4 degrees to 12 degrees . In general, for any given tie ratio, the increase in sweep decreased the C-N whereas increased C-M and C-A. A possible explanation, for the effect o f sweep, is given using the pressure data available in the literature. We a lso observed that for the sweeps considered, the t/c does not have anp effe ct on CN and CL but increasing t/c increased C-M and C-A, reduced (L/D)(max ) and moved the X-cp upstream. Blunt slab delta wings are shown to possess a unique property, wherein the C-D increases with increase in sweep at high er sweep angles. This property also reflects in the (L/D) characteristics. Furthermore, the slab delta wings does not exhibit the classical C-L alpha behaviour of sharp delta wings given in the literature. An empirical correl ation has been developed to correlate C-A0 over a wide range of Mach number , t/c and sweep. Linearised theory has been shown to be useful in predictin g the (L/D)(max) at Mach numbers as high as 20, for a wide range of t/c and sweep back angle.