A DIRECT NUMERICAL SIMULATION OF CHANNEL FLOW TRANSITION UNDER AN EXTERNAL BODY FORCE |
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| Authors: | C C HAO J N CHUNG |
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| Institution: | Department of Mechanical and Materials Engineering , Washington State University , Pullman, WA, 99164-2920, U.S.A |
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| Abstract: | This research seeks to increase our understanding on the laminar-turbulent transition under an external body force. Direct numerical simulation by the spectral method with a weak formulation is used to solve the transient 3-D Navier-Stokes equations. Initial disturbances consist of the finite-amplitude 2-D Tollmien-Schlichting wave and two 3-D oblique waves. Competitions among different modes were computed during transition for different Richardson numbers. It is found that the body force can modify the transition mechanism of flows between two vertical plates. The body force was found to hasten the formation of three-dimensional flow. A non-laminar flow induced by the body force may present when the background flow is still laminar. |
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| Keywords: | Direct numerical simulation spectral method weak formulation channel flow transition external body force |
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