Analysis of entropy generation for distributed heating in processing of materials by thermal convection
| Autor: | Ram Satish Kaluri, Tanmay Basak |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Fluid Flow and Transfer Processes
Convection Materials science Natural convection Basis sets Bejan number Conduction regime Convection regime Distributed heating Entropy generation Fluid friction Galerkin finite element methods Heat transfer irreversibility Local entropy Minimum entropy Square cavities Square cavity Temperature uniformity Thermal convections Thermal mixing Total entropy Velocity gradients Finite element method Flow measurement Fluids Friction Heating Entropy Convective heat transfer Mechanical Engineering Thermodynamics Condensed Matter Physics Thermal conduction Heat transfer Thermal |
| Zdroj: | International Journal of Heat and Mass Transfer. 54:2578-2594 |
| ISSN: | 0017-9310 |
| DOI: | 10.1016/j.ijheatmasstransfer.2011.02.003 |
| Popis: | Analysis of entropy generation has been carried out for square cavities with distributed heated sources filled with various materials involving wide range of Pr(=0.015, 0.7, 10, 1000) during the conduction and convection regime within Ra(=103 - 105). Entropy generation terms involving thermal and velocity gradients are evaluated accurately based on elemental basis set via Galerkin finite element method. Local entropy maps are analyzed in detail for various cases and the dominance of thermal and frictional irreversibilities is studied via average Bejan number. The heat transfer irreversibility is found to dominate during conduction regime while the fluid friction irreversibility dominates the entropy generation in the convection regime, except for the low Pr fluid based on the heating configuration of the cavity. Further, the variation of total entropy generation has been observed to be similar for different heating configurations for higher Pr fluids (=10, 1000) whereas, the configuration of cavity has been found to have little effect on total entropy generation for fluids with Pr = 0.7 during both conduction and convection regimes. Thermal mixing and degree of temperature uniformity due to distributed heating in various cases are also reported and optimum cases for processing of various fluids are presented based on minimum entropy generation. � 2011 Elsevier Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
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