S. M. Hosseinalipour - CAE & CFD Center, Mechanical Engineering Dept, Iran University of Science & Technology
M. Barzegar - CAE & CFD Center, Mechanical Engineering Dept, Iran University of Science & Technology
M. Abdollahzadeh - Dept. of Mechanical Engineering, Babol Noshirvani University of Technology

In this paper, Effectiveness of Aerospike assemblies as retractable drag-reducation devices for large-angle blunt cones flying th hypersonic Mach numbers is simulated numerically with a 120-deg apex-angle blunt cone at various angles of attack. The flow field around large angle blunt cones flying at hypersonic Mach numbers is complex with a strong detached shock wave in front. Visualization of these shock waves around the test models in ground based testing facilities is an essential part of the modern day research in hypersonic aerodynamics.The results indicate around 35% reduction in drag for the blunt cone with flat spike at zero degree angle of attack for a free stream Mach number of 5.7.5 In numerical analysis, 3-5 full Navier-stokes equations are solved with k- (SST) turbulence model. The visualized shock structure and the measured drag on the blunt cone with Aerospike agree well with the Experimental result. Surface convective heat-transfer rate measurement point on the blunt-cone surface. The measured heat-transfer rates fluctuate rates fluctuate by about 20% in the separated flow region as well as near the reattachment point indicating the unsteady flow field around the spiked blunt cone. A grid sensitivity analysis has been performed until grid-solution independence is achieved. The numerical results are compared with the measured pressure and surface heat flux distributions in the hypersonic shock tunnel HST2 and a good agreement is found, although some discrepancies are present, especially on the length of the recirculation region.

Drag Reduction, AeroSpike, Numerical Analysis, Hypersonic Flow