Session: 11-19-01: Fluid Measurements and Instrumentation/Young Engineer Paper (YEP) Contest

Paper Number: 166627

Effect of Aerospike Geometry on the Blunt Body of Formation 1221 at a Supersonic Flow Condition 

    The drag reduction capabilities of disked aerospike geometry are observed using ANSYS Fluent density-based CFD solver and k-omega SST turbulence model under low supersonic flow (Mach 2).  Modern computational fluid dynamic tools (e.g., ANSYS) can be used to predict the aerothermal heating environment around supersonic reentry space bodies. A student-designed supersonic reentry space body is modeled and simulated through geometry, mesh creation, and determination of relevant flight conditions. Aerodynamic and aerothermal analysis is carried out using the Reynolds-Averaged Navier Stokes model to better understand the aerodynamic drag, excessive thermal environments, and shock wave location around reentry space bodies at supersonic conditions. In this study, a hemispherical blunt body with 0.75 fineness ratio, 15-degree semi-angle, and flat base is considered at zero angle of attack without additional aerospikes to analyze its drag coefficient. These results are verified by monitoring solution values and comparing results to past studies’ experiments and simulations. A grid convergence study was also conducted to demonstrate that solution values converge to a finite value with finer meshing. These methods verify the geometry and meshing methods of the simple blunt body simulation for further studies with the additional spiked geometry added to the stagnation point of the blunt body.

    Simple aerospike geometry is then added to the nose to investigate the changes in drag coefficient and wall surface heat flux. This aerospike includes a small aero-disk at the tip of the spike. This study observes these properties as the aerospike’s length changes and as its disk diameter changes. A spike length to blunt body base diameter of 0.5 to 1.5 in increments of 0.25 were simulated for observing how length changes these properties. To observe these changes as disk diameter changes, disk diameters of 0.33, 0.5, and 0.75 times the base diameter were simulated. The length to blunt body base diameter of 1 was used as the disk diameter was investigated, and the disk diameter to blunt body base diameter of 0.33 was used as the length was investigated. Past studies show that the addition of an aerospike to the nose of a blunt body typically reduces drag; observing how changing the aerospike shape affects this reduction is the purpose of this study. This research provides basic information for the impact on aerospike geometry, specifically length and disk diameter dimensions, on the blunt body’s drag coefficient and heating for design purposes, as these will have significant impact on the design of a re-entry vehicle nose cone or other blunt body.

Presenting Author: Sophie Lewis California State University, Fresno

Presenting Author Biography: Ms. Sophie Lewis is a M.S. graduate student in the Mechanical Engineering Department at California State University, Fresno. Sophie is a 4.0 CGPA graduate student. Sophie received the mechanical engineering nomination for the Dean's Undergraduate Medalist in the Lyles College of Engineering at California State University, Fresno. Her research interest is in the supersonic and hypersonic aerothermodynamics.

Authors:

Sophie Lewis California State University, Fresno
Deify Law California State University, Fresno