NavierStokes analysis of cold scramjetafterbody flows
Abstract
The progress of two efforts in coding solutions of NavierStokes equations is summarized. The first effort concerns a 3D space marching parabolized NavierStokes (PNS) code being modified to compute the supersonic mixing flow through an internal/external expansion nozzle with multicomponent gases. The 3D PNS equations, coupled with a set of species continuity equations, are solved using an implicit finite difference scheme. The completed work is summarized and includes code modifications for four chemical species, computing the flow upstream of the upper cowl for a theoretical air mixture, developing an initial plane solution for the inner nozzle region, and computing the flow inside the nozzle for both a N2/O2 mixture and a Freon12/Ar mixture, and plotting densitypressure contours for the inner nozzle region. The second effort concerns a full NavierStokes code. The species continuity equations account for the diffusion of multiple gases. This 3D explicit afterbody code has the ability to use high order numerical integration schemes such as the 4th order MacCormack, and the GottliebMacCormack schemes. Changes to the work are listed and include, but are not limited to: (1) internal/external flow capability; (2) new treatments of the cowl wall boundary conditions and relaxed computations around the cowl region and cowl tip; (3) the entering of the thermodynamic and transport properties of Freon12, Ar, O, and N; (4) modification to the BaldwinLomax turbulence model to account for turbulent eddies generated by cowl walls inside and external to the nozzle; and (5) adopting a relaxation formula to account for the turbulence in the mixing shear layer.
 Publication:

Progress Report
 Pub Date:
 April 1989
 Bibcode:
 1989odun.reptR....B
 Keywords:

 Afterbodies;
 Computational Fluid Dynamics;
 Finite Difference Theory;
 Hypersonic Flow;
 Hypersonic Nozzles;
 NavierStokes Equation;
 Nozzle Flow;
 Parabolic Differential Equations;
 Supersonic Flow;
 Applications Programs (Computers);
 Continuity Equation;
 Flow Distribution;
 Free Flow;
 Isobars (Pressure);
 Nozzle Design;
 Supersonic Combustion Ramjet Engines;
 Fluid Mechanics and Heat Transfer