Pulsed Turbulent Impinging Jet at Large Temperature Differences: A CFD Study of the Heat Transfer Characteristics
Peng Xu1, Arun S. Mujumdar2, Hee Joo Poh3 and Boming Yu4
1College of Science, China Jiliang University, Hangzhou, Zhejiang 310018, China.
xupenghust@yahoo.com.cn
2 Fellow, ASME, Mechanical Engineering Department, National University of Singapore, 117576 Singapore.
mpeasm@nus.edu.sg
3Fluid Dynamics Division, Institute of High Performance Computing, 117528 Singapore.
pohhj@ihpc.a-star.edu.sg
4School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
yuboming2003@yahoo.com.cn
ABSTRACT
Pulsed impinging jets have received much attention in recent years for their potential in heat and mass transfer enhancement. A numerical investigation has been performed on a two dimensional pulsed turbulent impinging jet for large temperature differences between the jet flow and the impinging surface to examine the effect of temperature-dependent thermophysical properties along with pulsation of the jet on the local Nusselt number distribution on the target surface. Predictions with various turbulence models are compared, and the effects of temperature difference, Reynolds number, pulsation frequency and amplitude as well as the geometrical configurations on local averaged heat transfer are analyzed for both cooling and heating applications. The local time-averaged Nusselt numbers calculated with various thermal property values at the jet, film and impingement surface temperatures differ significantly for large temperature difference cases ( > 100K).
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