Launch-Vehicle Simulations Using a Concurrent, Implicit Navier-Stokes Solver

A large-scale multibody launch-vehicle simulation at supersonic speed is described. The simulation was conducted on a 256-node Intel Delta machine using a concurrent implementation of the Aerospace Launch System Implicit/Explicit Navier-Stokes code. This general Navier-Stokes solver has been used for a broad range of practical simulations. Those of interest involve a variety of nozzle flows and multibody launch-vehicle configurations such as the Titan IV. The code utilizes a finite volume total-variation-diminishing scheme for computing both steady and unsteady solutions to the three-dimensional compressible Navier-Stokes equations. The scheme is second-order accurate in space and is fully vectorized for operation on Cray computers. A line-by-line relaxation algorithm is used to accelerate the convergence for steady-state solutions. The code employs a variety of features that increase its practical utility. These include multibody configurations, turbulence modeling, and propellant-burning capabilities. The procedures for extending this code to distributed-memory parallel computers are described. Results of the application to a Titan IV launch vehicle at freestream Mach number 1.6 are discussed. Nomenclature E,F,G = flux vectors E, F, G = transformed flux vectors e = total energy per unit volume cx>£.v> &z = unit vectors in the x,y, and z directions, respectively J = Jacobian of the transformation k = thermal conductivity p = pressure q = heat transfer vector T = temperature t = time