variavel0=<b>WILSON F. N. SANTOS</b> - wilson@lcp.inpe.br INPE
<b>Abstract.</b> A numerical study was performed to determine the upstream effects of leading edge thickness on the rarefied hypersonic flow over wedges at zero angle of attack. The simulations were performed by using a Direct Simulation Monte Carlo Method. A method that has demonstrated to yield excellent comparisons with flight- and ground-test data, and that properly accounts for nonequilibrium aspects of the flow that arise near the leading edge and that are especially important at high Mach number. Some significant differences between sharp and blunt leading edges were noted on the flowfield structure and on the aerodynamic surface quantities. It was found that the upstream effects have different influence on velocity, density, pressure and temperature along the stagnation streamline ahead of the leading edges. Interesting features observed in the surface fluxes showed that small leading edge thickness compared to the freestream mean free path still has important effects on high Mach number leading edge flows.
<b>Keywords.</b> DSMC, Hypersonic flow, rarefied flow, blunt leading edge, wedge..