Date of Award

Fall 1989

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Mechanical & Aerospace Engineering

Program/Concentration

Mechanical Engineering

Committee Director

Oktay Baysal

Committee Member

Surendra N. Tiwari

Committee Member

James L. Pittman

Call Number for Print

Special Collections; LD4331.E56E54

Abstract

The recent renewal of interest in hypersonic aerodynamics, brought about largely in part due to the development of the National Aerospace Plane (NASP), is resulting in an increased reliance on computational fluid dynamics for flowfield data in this flight regime. The design of the nozzle-afterbody section for a hypersonic transport such as the NASP is currently underway, and is being conducted using both computational fluid dynamics and cold, non-reacting, simulant gas experimental models. In this study, a computational analysis is conducted for the flow through a scramjet nozzle-afterbody test section.

Computations have been performed for a cold gas simulation of a scramjet afterbody flowfield using the Reynolds averaged Navier-Stokes equations. The computations are compared with the results obtained from an experimental study of scramjet module nozzle-afterbody flows. The expansion of a supersonic flow through an internal/external

nozzle-afterbody configuration and its viscous mixing with a hypersonic freestream flow of air is computed using two and three-dimensional upwind, finite volume, Navier-Stokes schemes. The Reynolds stresses are represented by a Baldwin-Lomax algebraic turbulence model with modifications to account for separated flow, multiple wall geometry, and turbulent wake flow. Two-dimensional computations are performed on both fixed and flow adapted grids, and three-dimensional results are computed over a half-span nozzle model on a fixed grid. The results obtained from the adapted grid computations show improved accuracy and resolution, especially in regions where shocks and shear layers occur. Afterbody flowfield results are presented for two-dimensional over-expanded (off design) and under-expanded nozzles, and a three-dimensional spanwise symmetric nozzle. The two-dimensional and three-dimensional nozzle computations compare favorably with experimental results. Furthermore, the results demonstrate that the solutions obtained from the computational fluid dynamics algorithms used in this study, can be used to expand the database for these types of nozzle-afterbody configurations.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

DOI

10.25777/j8rn-8874

Share

COinS