ISSN 1002-1027  CN 11-2952/G2

Acta scientiarum naturalium Universitatis Pekinensis

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Turbulent Fluxes over Heterogeneous Surfaces and the Blending Height

ZHOU Cheng1, CHEN Jiayi1, 2, CAI Xuhui2   

  • Received:2005-03-22 Online:2006-05-20 Published:2006-05-20

Abstract: The concept and application of blending height are introduced. Large-eddy simulations were conducted to study the blending height in convective boundary layers over heterogeneously heated surfaces. The influences of heterogeneous length, heterogeneous strength and wind speed on blending height were investigated. The results show that the blending heights are mainly determined by the heterogeneous length and wind speed, while less influenced by the heterogeneous strength. Blending height appears at the height where the spatial standard deviation of heat flux decreases to 5% of that on the surface and can be fitted as Zb = 1/Cwm * w'θ'sfc/Θ0 * Lahetero/Ub, with a=1.266, b=0.854, Cwm=3.205×10-3.