Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary Conditions
Time evolution features of kinetic and thermal entropy generation rates in turbulent Rayleigh-Bénard (RB) convection with mixed insulating and conducting boundary conditions at <i>Ra</i> = 10<sup>9</sup> are numerically investigated using the lattice Boltzmann method. The sta...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-06-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/22/6/672 |
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| author | Yikun Wei Pingping Shen Zhengdao Wang Hong Liang Yuehong Qian |
| author_facet | Yikun Wei Pingping Shen Zhengdao Wang Hong Liang Yuehong Qian |
| author_sort | Yikun Wei |
| collection | DOAJ |
| description | Time evolution features of kinetic and thermal entropy generation rates in turbulent Rayleigh-Bénard (RB) convection with mixed insulating and conducting boundary conditions at <i>Ra</i> = 10<sup>9</sup> are numerically investigated using the lattice Boltzmann method. The state of flow gradually develops from laminar flow to full turbulent thermal convection motion, and further evolves from full turbulent thermal convection to dissipation flow in the process of turbulent energy transfer. It was seen that the viscous, thermal, and total entropy generation rates gradually increase in wide range of <i>t</i>/τ < 32 with temporal evolution. However, the viscous, thermal, and total entropy generation rates evidently decrease at time <i>t</i>/τ = 64 compared to that of early time. The probability density function distributions, spatial-temporal features of the viscous, thermal, and total entropy generation rates in the closed system provide significant physical insight into the process of the energy injection, the kinetic energy, the kinetic energy transfer, the thermal energy transfer, the viscous dissipated flow and thermal dissipation. |
| first_indexed | 2024-03-10T19:07:08Z |
| format | Article |
| id | doaj.art-7603b687ffae4221be2dbed3853c3b29 |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-03-10T19:07:08Z |
| publishDate | 2020-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-7603b687ffae4221be2dbed3853c3b292023-11-20T04:04:38ZengMDPI AGEntropy1099-43002020-06-0122667210.3390/e22060672Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary ConditionsYikun Wei0Pingping Shen1Zhengdao Wang2Hong Liang3Yuehong Qian4Joint Engineering Lab of Fluid Transmission System Technology, Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaJoint Engineering Lab of Fluid Transmission System Technology, Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaJoint Engineering Lab of Fluid Transmission System Technology, Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaDepartment of Physics, Hangzhou Dianzi University, Hangzhou 310018, ChinaSchool of Mathematical Science, Soochow University, Suzhou 215006, ChinaTime evolution features of kinetic and thermal entropy generation rates in turbulent Rayleigh-Bénard (RB) convection with mixed insulating and conducting boundary conditions at <i>Ra</i> = 10<sup>9</sup> are numerically investigated using the lattice Boltzmann method. The state of flow gradually develops from laminar flow to full turbulent thermal convection motion, and further evolves from full turbulent thermal convection to dissipation flow in the process of turbulent energy transfer. It was seen that the viscous, thermal, and total entropy generation rates gradually increase in wide range of <i>t</i>/τ < 32 with temporal evolution. However, the viscous, thermal, and total entropy generation rates evidently decrease at time <i>t</i>/τ = 64 compared to that of early time. The probability density function distributions, spatial-temporal features of the viscous, thermal, and total entropy generation rates in the closed system provide significant physical insight into the process of the energy injection, the kinetic energy, the kinetic energy transfer, the thermal energy transfer, the viscous dissipated flow and thermal dissipation.https://www.mdpi.com/1099-4300/22/6/672entropy generation ratethermal plumemixed boundary conditionsheat transfer |
| spellingShingle | Yikun Wei Pingping Shen Zhengdao Wang Hong Liang Yuehong Qian Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary Conditions Entropy entropy generation rate thermal plume mixed boundary conditions heat transfer |
| title | Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary Conditions |
| title_full | Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary Conditions |
| title_fullStr | Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary Conditions |
| title_full_unstemmed | Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary Conditions |
| title_short | Time Evolution Features of Entropy Generation Rate in Turbulent Rayleigh-Bénard Convection with Mixed Insulating and Conducting Boundary Conditions |
| title_sort | time evolution features of entropy generation rate in turbulent rayleigh benard convection with mixed insulating and conducting boundary conditions |
| topic | entropy generation rate thermal plume mixed boundary conditions heat transfer |
| url | https://www.mdpi.com/1099-4300/22/6/672 |
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