Convection Heat Transfer Enhancement on Recirculating Flows in a Backward Facing Step: The Effects of a Small Square Turbulence Promoter
| Autor: | Miguel Vaz, Gregory T. Gargioni, Paulo S. B. Zdanski |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics Work (thermodynamics) Turbulent diffusion Convective heat transfer Turbulence K-epsilon turbulence model Mechanical Engineering Turbulence modeling 02 engineering and technology Mechanics K-omega turbulence model Condensed Matter Physics 01 natural sciences Nusselt number 010305 fluids & plasmas Physics::Fluid Dynamics 020303 mechanical engineering & transports 0203 mechanical engineering 0103 physical sciences |
| Zdroj: | Heat Transfer Engineering. 37:162-171 |
| ISSN: | 1521-0537 0145-7632 |
| Popis: | This work addresses the numerical simulation of incompressible turbulent recirculating channel flows in a backward-facing step. The effects of a small square turbulence promoter on convection heat transfer are evaluated through a parametric study. The governing equations comprise the time-averaged mass, linear momentum, and energy conservation principles in conjunction with the two-equation k–epsilon turbulence model. The study is focused on the assessment of the local and global Nusselt numbers at the channel stepped wall. The main results indicate that a maximum increment around 15% on the average Nusselt number can be achieved by using a small turbulence promoter to disturb the flow. Furthermore, it was found that the peak of the local Nusselt number on the stepped wall is located in the region where the turbulent diffusion is maximum in the near wall region. |
| Databáze: | OpenAIRE |
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