Выходит 18 номеров в год
ISSN Печать: 1064-2285
ISSN Онлайн: 2162-6561
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Numerical Investigations of Opposing Mixed Convection Heat Transfer in Vertical Flat Channel. 1. Laminar Mixed Convection and Transition to Vortex Flow in the Case of Symmetrical Heating
Краткое описание
In this paper we present the results of numerical investigation into the local opposing mixed convection heat transfer in a vertical flat channel with symmetrical heating in laminar airflow. Numerical two-dimensional simulation was performed using FLUENT 6.1 code. The investigations were performed under steady state flow conditions in airflow of 0.1; 0.2 and 0.4 MPa pressure at the Reynolds numbers from 1.5·103 up to 4.3·103 with the Grq number varying from 1.65·105 to 3.1·109 in order to define the effect of the influence of buoyancy on heat transfer. Numerical modeling demonstrates that under small buoyancy effect there are only small transformations in the velocity profile but flow is oriented downward (direction of forced flow). With increase in buoyancy forces, the flow separation occurs at some distance from the beginning of the heated channel section. With further increase in buoyancy, the position point of flow separation moves towards the beginning of a heated section. The channel wall temperature decreases noticeably at the flow separation point. Correlations for calculating heat transfer in the laminar mixed convection region and for the determination of the position of flow separation from the wall are suggested.
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Scheele, G. F., Rosen, E. M., and Hanratty, T. J. , Effects of natural convection on transition to turbulence in vertical pipes.
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Petukhov, B. S., Polyakov, A. F., and Strigin, B. K. , Issledovanie teploobmena v trubakh pri viazkostno-gravitatsionnom techenii (Heat Transfer Investigations in Tubes with Viscous-Gravitational Flow).
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Petukhov, B. S., Genin, L. G., and Kovalev, S. A. , Teploobmen v yadernykh us-tanovkakh (Heat Transfer in Nuclear Plants).
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Hallman, T. M. , Combined forced and free laminar convection in vertical tubes with uniform internal heat generation.
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Scheele, G. F. and Hanratty, T. J. , Effects of natural convection instabilities on rates of heat transfer at low Reynolds numbers.
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Fluent 6.1 Documentation.
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Kenjeres, K. and Hanjalic, K. , Numerical insight into flow structure in ultraturbulent thermal convection.
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Petukhov, B. S. and Polyakov, A. F. , Teploobmen pri smeshannoi turbulentnoi konvektsii (Turbulent Mixed-Convection Heat Transfer).
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Zaman Shuja Shahzada, Yilbas Bekir, Flow over a heated block in a vertical channel , International Journal of Numerical Methods for Heat & Fluid Flow, 24, 5, 2014. Crossref