Numerical Simulation on Laminar-Turbulent Transition of the Channel Flow with Simulated Wall Roughness
Direct numerical simulation on laminar-turbulent transition of the channel flow is conducted to elucidate the effect of distributed wall roughness on the transition. In the numerical simulation, distributed wall roughness is simulated by a periodic suction/blowing (PSB) acted on the channel wall. It is found from the simulation that the PSB simulates well a kind of two-dimensional distributed wall roughness and can strongly destabilize the channel flow. As a result, it induces the transition of the sub-critical channel flow with its Reynolds number equal to 5000 when it has a large amplitude. On the other hand, it accelerates the transition process of the super-critical channel flow with its Reynolds number equal to 10000. The critical amplitude of the PSB under which it has no effect on the transition is found.
Keywordschannel flow transition wall roughness numerical simulation
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- Reshotko, E.: Disturbances in a Laminar boundary Layer due to Distributed Surface Roughness, Turbulence and Chaotic Phenomena in Fluids, Tstsumi, T. ed., Elsevier Sci. Publ. ( 1984) 39–46.Google Scholar
- Yamamoto, K. , Murase, T. and Floryan, J. M.: Numerical Simulation of Laminar-Turbulent Transition in a Channel Flow with a Periodic Suction and Blowing, Proceedings of the 9th and 10th NAL Workshop on “Investigation and Control of Boudary Layer Transition”, NAL Special Publ., SP-18 (1992) 5–9.Google Scholar
- Floryan, J. M., Yamamoto, K. and Murase, T.: Laminar-Turbulent Transition Process in the Presence of Simulated Wall Roughness, Canad. Aero. Space J. 38 (1992) 173–182.Google Scholar
- Itoh, N.: A power Series Method for the Numerical Treatment of the Orr-Sommer-feld Equation, Trans. Japan Soc. Aero. Space Sci. 17 (1974) 65–75.Google Scholar
- Herbert, T.: Finite Amplitude Stability of Plane Parallel Flow, Laminar-Turbulent Transition, AGARD Conf. Proc. No. 224 (1977) 3.1–3.10.Google Scholar