Aerodynamic Heating of a Hypersonic Projectile with Forward-Facing Ellipsoid Cavity at Nose

摘要

Numerical experiments are carried out using a commercially available computational-fluid-dynamics code to investigate the aerodynamic heating of a hemisphere-cylinder with a forward-facing ellipsoid cavity at nose in atmosphere. A wide range ellipsoid cavity of depths varying between 3 to 30 mm placed axisymmetrically at the nose of the blunt body with base diameter 40 mm and overall length 70 mm have been investigated. The ratios of semimajor axis to semiminor axis of these cavities (a/b) are 3, 2, or 1.5, where semimajor axis a is equal to the depth of cavity d and the semiminor axis b is close to the lip radius r of the cavity. All computations have been done at a freestream Mach number of 10.1 and static pressure and temperature of 16,066 Pa and 216.65 K respectively. The steady-state solutions of axisymmetric Navier-Stokes equations are obtained using a time marching approach in order to study the aerodynamic heating of a hypersonic projectile with a forward-facing ellipsoid cavity at a nose. The simulation results suggest that, though the stagnation-point heat flux and the total heat-transfer rates to the blunt body can be favorably reduced by the introduction of ellipsoid cavity, the local heating at lip can become drastically high.