Axisymmetric and 2-D Blunt-Body Flowfields at Mach 20


Mach 20, perfect-gas flow over a spherical and a cylindrical blunt-body, at a flight altitude of 100 kft and zero angle of attack. Additional assumptions include an isothermal wall-temperature of 500 R, and a nose radius of 0.5 inch.

Computational Grid: Computational grid used consisted of 65 body-normal grid points and 25 streamwise grid points in the blunt-body FNS (Full Navier-Stokes) Zone (Zone 1). At the wall, very fine grid spacing was used, resulting in a grid spacing at the stagnation point of 7.8×10-8 inch and 2.2×10-7 inch, respectively, for the axisymmetric and 2-D cases.

PC Hardware Used: Computations were done on a very old 133 MHz Intel Pentium PC, with 1 GB hard disk and 32 Meg RAM.

Computational Time Required: Total clock time used in axisymmetric was 25 min, while the time taken for the 2-D computation was 30 min .

Snapshots of Predicted Flowfield:

(a) Predicted axisymmetric and 2D pressure contours in the blunt-body region, and comparison with empirical correlations.

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(b) Predicted axisymmetric and 2D temperature contours in the blunt-body region, and comparison with empirical correlations.

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