Date of Award


Publication Type

Master Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering

First Advisor

David Ting

Second Advisor

Xiaohong Xu


CFD, Flow, Trapezoidal Cavity, Turbulence, Wind tunnel




The effect of Reynolds number (Re), turbulence intensity (Tu) and aspect ratio (W/D) on flow above and inside a trapezoidal cavity is studied in terms of the vortex characteristics inside the cavity and the normalized volumetric air exchanged rate from the cavity (Qnormalized). A CFD model has been set and validated based on limited wind tunnel data. With increasing Re (60000, 123000, and 181000), the center of vortex moved toward the trailing edge of the cavity, Qnormalized increased, and the vortex inside the cavity had more strength (Vorticity magnitude increased). With increasing Tu (0.67%, 5%, and 15%), the center of vortex moved toward the leading edge in W/D of 2, and Qnormalized did not change significantly. With increasing W/D (2, 4, and 6), the center of vortex moved toward the leading edge, and Qnormalized increased significantly. W/D was found to be the most significant factor affecting vortex characteristics and Qnormalized. The cavity was "open" in W/D of 2 and 4, whereas, the cavity was found to be "closed and transitional" in W/D of 6.