Coarse Particles in Homogeneous Non-Newtonian Slurries: Combined Effects of Shear-Thinning Viscosity and Fluid Yield Stress on Drag and Heat Transfer from Hemispherical Particles

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• 作者：Om Prakash ; S. A. Patel ; A. K. Gupta…
• 关键词：Hemisphere ; Bingham number ; Nusselt number ; Herschel–Bulkley fluid ; Reynolds number
• 刊名：Transactions of the Indian Institute of Metals
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：70
• 期：2
• 页码：341-358
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Metallic Materials; Materials Science, general; Tribology, Corrosion and Coatings;
• 出版者：Springer India
• ISSN：0975-1645
• 卷排序：70

文摘

In this work, the momentum and energy equations have been solved numerically for predicting the hydrodynamic drag and heat transfer coefficient for a hemispherical particle submerged in a flow stream of yield-pseudoplastic fluids in order to elucidate the combined effects of shear-thinning viscosity and fluid yield stress. In this case, the momentum transfer aspects are influenced by the values of the Reynolds number (0.1 ≤ Re ≤ 100), Bingham number(0 ≤ Bn ≤ 100), shear-thinning index (0.2 ≤ n ≤ 1) and the orientation of the hemisphere. Similarly, the corresponding heat transfer results show additional dependence on the Prandtl number (0.7 ≤ Pr ≤ 100) and the type of thermal (isothermal or isoflux) boundary condition specified on the surface of the heated hemisphere. The numerical results are discussed in terms of the size and shape of the fluid-like yielded regions, wake lengths, hydrodynamic drag and heat transfer coefficients as functions of the preceding dimensionless parameters. Finally, the present values of the drag coefficient and Nusselt number have been fitted using simple expressions thereby enabling the interpolation of the present results for the intermediate values of the parameters and/or their prediction in a new application.