Calculations of Flowfield About Indented Nosetips,
NAVAL SURFACE WEAPONS CENTER SILVER SPRING MD
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The unsteady implicit numerical procedure for solving Euler or Navier- Stokes equations with thin-layer approximation for hypersonic flows over blunt noses developed by Kutler et al is examined and applied to compute the flowfield of hypersonic flows over a series of four severely indented nosetip shapes. For inviscid flows routing calculation fails to give a solution and a special calculation procedure has been developed in order to obtain reasonable solutions. For viscous flows, comparisons of calculated results and measured data are not satisfactory. The calculated temperature field is poor and difficulties to simulate flows with large separation bubble and turbulent flows are described. Consequently, a reanalysis of the complete calculation procedure for solving the full Navier-Stokes equations has been carried out. The original code was then revised by rewriting all the viscous subroutines according to the new analysis for thin-layer theory without turbulence model. The revised code has been applied to compute laminar flow over a hemisphere-cylinder and a sphere-cone. The new results do not show that temperature is a mesh dependent variable as reported by Kutler et al and the temperature field compare well with the available solution for full Navier-Stokes equations and boundary layer calculation. Finally, a coupling of the nosetip code with an existing NSWC supersonic marching code for inviscid afterbody solution has also been carried out.
- Numerical Mathematics
- Fluid Mechanics