Three-dimensional Navier-Stokes simulations have been done for transonic and low supersonic flow past a nonaxisymmetric nozzle typical of those advocated for advanced fighter airplanes. The jet exhaust is included in the calculations. The investigation compares the performance of the unmodified Baldwin-Lomax turbulence model with its performance when enhanced by the Degani-Schiff and the Goldberg modifications. Solutions are presented for Mach numbers of 0.80,0.94, and 1.20 at 0-deg angle of attack and a Reynolds number of 20 x 10 6 . The numerical results, which are compared to the wind-tunnel data, show that the three turbulence models predict considerably different shock locations, separated-flow regions, and flowfields. NomenclatureA, B, Ci,C 2 = constants in the Goldberg modification for turbulence modelsfunction in the Baldwin-Lomax turbulence model [see Eq. (6)] F, G, H = flux vectors in the transformed coordinate £, T/, f directions respectively 9 =Gaussian [see Eq. (8)] K = Clauser constant L = reference length, length of model from nose to jet exit (63 in.) £ = mixing length for turbulent viscosity Moo = free-stream Mach number n = normal distance from the wall n + = law-of-the-wall coordinate, (n\lp w r w )/n w p = pressure Q = transformed vector of dependent flow variables #00 = freestream dynamic pressure, R = Reynolds number based on length of model from nose to nozzle exit / = time u s -velocity scale for separated flows [see Eq. (8)] u, v, w = velocities in the physical coordinate directions x,y 9 z, respectively x, y, z = physical (Cartesian) coordinates in the axial, horizontal, and vertical directions respectively, (origin at nose of model) a. = angle of attack, deg p = viscosity £, 77, f = generalized coordinates in transformed coordinate system (approximately the axial, circumferential, and radial directions) p = density T W = local shear stress at wall co = vorticity Subscripts i = inner max = maximum min = minimum o = outer s = separated t -turbulent w = wall oo = freestream conditionsUnless otherwise noted, all variables in this paper are nondimensionalized by appropriate combinations of the free-stream parameters and the reference length L.

A 3.5-year effort to characterize the aerodynamic behavior of the Ares I-X Flight Test Vehicle (AIX FTV) is described in this paper. The AIX FTV was designed to be representative of the Ares I Crew Launch Vehicle (CLV). While there are several differences in the outer mold line from the current revision of the CLV, the overall length, mass distribution, and flight systems of the two vehicles are very similar. This paper briefly touches on each of the aerodynamic databases developed in the program, describing the methodology employed, experimental and computational contributions to the generation of the databases, and how well the databases and underlying computations compare to actual flight test results.

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