Transient conjugated heat transfer in thermally developing laminar flow in thick walled pipes and minipipes with time periodically varying wall temperature boundary condition
| Autor: | Aziz Hakan Altun, Ali Ateş, Şefik Bilir |
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| Rok vydání: | 2016 |
| Předmět: |
Fluid Flow and Transfer Processes
Dynamic scraped surface heat exchanger Materials science Convective heat transfer 020209 energy Mechanical Engineering Thermodynamics Film temperature Laminar flow 02 engineering and technology Heat transfer coefficient Mechanics Condensed Matter Physics Thermal conduction Thermal diffusivity Physics::Fluid Dynamics Heat transfer 0202 electrical engineering electronic engineering information engineering |
| Zdroj: | International Journal of Heat and Mass Transfer. 92:643-657 |
| ISSN: | 0017-9310 |
| DOI: | 10.1016/j.ijheatmasstransfer.2015.09.011 |
| Popis: | Transient conjugated heat transfer for thermally developing laminar flow in thick walled pipes is analyzed involving two-dimensional wall and axial fluid conduction. A two-regional, initially isothermal pipe is considered and the problem is handled for hydrodynamically developed flow with periodically time-varying outer wall temperature in the downstream region. The problem is solved numerically by a finite-difference method and a parametric study is done to analyse the effects of four defining parameters namely, wall thickness ratio, wall-to-fluid conductivity ratio, wall-to-fluid thermal diffusivity ratio, the Peclet number and also the effect of angular frequency. Considerable amount of heat is transferred through the upstream region due to both wall and fluid axial conduction. Heat transfer characteristics change periodically in time similar to the periodic change in the outer wall temperature. The results are found to be affected by the parameter values and by the angular frequency. |
| Databáze: | OpenAIRE |
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