Numerical simulation of a turbulent flow over an axisymmetric hill

Castagna, Jony; Yao, Yufeng; Yao, Jun

Abstract

Simulation of a turbulent °ow over an axisymmetric hill has been carried out to study three-dimensional °ow separation and reattachment that occur on the lee-side of the geome-try. A total of four simulations are considered at low Reynolds number of ReH=6500, based on free-stream quantities and hill height (H). Synthetic in°ow generation and data feed-in methods are tested on a trial coarse grid and the results have shown good agreements be-tween two techniques, conrming the feasibility of the in°ow data feed-in treatment. Fine grid simulations continue on a baseline domain and an extra longer and wider domain, both having the same grid resolution of x+ = 12:5, z+ = 6:5, and y+ 1 = 1:0 and about 10 points in the viscous sublayer. It was found that a separation bubble exists at the foot of the wind-side of the hill and the incoming turbulent boundary layer °ow undergoes re-laminarization process around the crest of the hill. These lead to a significant °ow sep-aration at the lee-side of the hill, where a very large primary separation bubble embedded with a smaller secondary separations have been captured. The present low-Re simulation reveals some °ow features that are not observed by high-Re experiments, thus is useful for future experimental studies. Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

• Presentation Conference Type: Conference Paper (published)
• Conference Name: The 50th AIAA Aerospace Sciences Meeting
• Start Date: Jan 9, 2012
• End Date: Jan 12, 2012
• Publication Date: Nov 6, 2012
• Deposit Date: Jun 23, 2021
• Series Number: AIAA-2012-0098
• DOI: https://doi.org/10.2514/6.2012-98
• Public URL: https://uwe-repository.worktribe.com/output/7487818