Date of Award

3-1999

Document Type

Thesis

Degree Name

Master of Science in Aeronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

Jeffrey P. Bons, PhD

Abstract

Experimental and computational heat transfer investigations were performed on a cavity with an inclined trailing wall (20-degrees to the horizontal), simulating one under investigation for use in a scramjet engine. Heat transfer data are reported in the form of Stanton number obtained using a curve fit to the recorded transient surface temperature history under cold flow conditions. Ascending from the reattachment point, the Stanton number increased by nearly 50% due to flow compression. This effect of flow compression was also evident at the junction of the cavity floor and inclined trailing wall, where the Stanton number also increased by 50%. Descending from the reattachment point, the Stanton number increased by 30% due to flow recirculation. Downstream of the inclined trailing wall, the Stanton number increased by 90% due to the boundary layer-shock interaction when compared to that at the same axial location on a flat plate. A schlieren flow visualization technique was employed, showing the formation of the oblique shock from coalescing weak compression waves. For comparison, a 2-D Navier-Stokes CFD analysis was performed using a realizable k-epsilon turbulence model. In the cavity, the CFD Stanton number results were an order of magnitude lower than the experimental values, while downstream of the cavity, the CFD Stanton number results were 40% lower than the experimental results. Similar differences are noted within the open literature with application of various turbulence models, suggesting that the flow in the cavity is quite complex and the use of two equation turbulence models requires closer investigation.

AFIT Designator

AFIT-GAE-ENY-99M-07

DTIC Accession Number

ADA361609

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