Effects of Sonic Line Transition on Aerothermodynamics of the Mars Pathfinder Probe

摘要: Flowfield solutions over the Mars Pathfinder Probe spanning trajectory through Martian atmosphere at angles of attack from 0 to 11 degrees are obtained. Aerodynamic coefficients derived these reveal two regions where derivative pitching moment with respect angle is positive small attack. The behavior associated transition sonic line location between blunted nose and windside shoulder 70 degree half-angle cone in a gas low effective ratio specific heats. first occurs as shock layer chemistry evolves highly nonequilibrium near equilibrium, above approximately 6.5 km/s 40 km altitude, causing heat decrease. next an equilibrium flow regime velocities decrease 3.5 increases again decreasing ent halpy. effects expansion into wake more strongly felt on fustrum when sits shoulder. also produces counter-intuitive trend which heating levels increasing resulting increase t he radius curvature. Six-degree-of-freedom analyses utilizing computed aerodynamic coe fficients predict moderate, 3 4 total probe, spinning 2 revolutions per minute, passes regions.