Conjugate Wall Conduction-Fluid Natural Convection in a Three-Dimensional Inclined Enclosure

Abstract

Laminar conjugate conduction-natural convection heat transfer in a 3-D inclined cubic enclosure comprised of finite thickness conductive walls and central cavity is numerically investigated. The dimensionless governing equations describing the convective flow and wall heat conduction are solved by the high accuracy multidomain pseudospectral method. Computations are performed for different Rayleigh numbers (10³ ≤ Ra* ≤ 10⁶), thermal conductivity ratios (1 ≤ k ≤ 100), dimensionless wall thickness (0 ≤ s ≤ 0.25), and enclosure inclinations (−30° ≤ α ₁ ≤ 30°, 0° ≤ α ₂ ≤ 45°). The effects of the above controlling parameters on the heat transfer performances of the enclosure system are investigated in detail, with emphases on the variations of wall conduction and fluid convection heat transfer, and the interactive heat transfer conditions between solid walls and fluid in the central cavity. Numerical results reveal that the existence of enclosure walls reduces the temperature gradient across the cavity and alters the temperature distribution within the solid walls; thus, the fluid convection is complexly determined by the combined effects of k and s, and is greatly affected by enclosure inclinations at high Rayleigh numbers. Moreover, the temperature distributions and solid-fluid interactive heat transfer conditions are provided for further interpretation and demonstration of the effects of the solid walls.

Acknowledgments

The authors appreciate the financial support provided by the National Natural Science Foundation of China (nos. 50725621 and 51176146), and the National High Technology Research and Development Program (863 Program) of China (no. 2009AA01A135). W. Zhang and Z. Huang would like to thank Lei Zhao for his assistance in coordinating the computer resources, and Zhongguo Sun, Yangyang Liang, Wei Wang, and Baotong Wang for their helpful suggestions. Comments from the anonymous reviewers are also appreciated.