Browsing by Author "Hinman, William"

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    Application of simplified numerical and analytical methods for rapid analysis in atmospheric entry vehicle design
    (AIAA Conference, 2015) Hinman, William; Johansen, Craig; Wilson, Steven
    Selected simplified numerical and analytical methods are applied to flow around hypersonic adiabatic blunt bodies. In particular, selected methods that are well defined in the literature, such as the modified Newton’s method, transformed finite difference grid in the shock layer, and the method of characteristics in the supersonic region, are utilized to solve the flow around an adiabatic circular cylinder at Mach 6. The results are compared to results obtained by numerical simulation of the compressible Navier-Stokes equations. The comparison is used to draw conclusions about the applicability and accuracy of these methods as they apply to low Reynolds number, small radius of curvature bodies such as atmospheric entry vehicles. A minor improvement to the results is proposed by the inclusion of an iterative interaction between the boundary layer displacement thickness, and the external inviscid free-stream.
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    Computational fluid dynamics study of optimized hypersonic leading edge geometries
    (AIAA Conference, 2015) Hinman, William; Schmitt, Simon; Johansen, Craig; Rodi, Patrick
    An aerothermal optimization study of two-dimensional hypersonic leading edge geometries has been performed. The accuracy of a simplified model and a reduced order numerical model was assessed through comparison to simulations of the compressible Navier-Stokes equations performed in OpenFOAM. Specifically, the estimated surface pressure, and laminar convective heating distributions have been compared. The simplified model was found to have compromised accuracy in regions of high and low surface curvature. The reduced order numerical model was found to give accurate results with significantly reduced computational cost compared to complete Navier-Stokes simulations. Optimizations were then performed using the simplified analysis technique, and the reduced order numerical model. The performance of the optimized hypersonic leading edge geometries was analyzed using OpenFOAM. The results show that both methods achieve a similar geometric result. However, the quality of the optimization is improved by using the reduced order numerical model. An analysis was performed in the design space immediately surrounding the optimized geometry to assess the impact of small geometric changes on aerothermal performance. The results show that even small changes in leading edge geometry can have a significant influence on aerothermal performance.