scholarly journals Numerical Simulation of Separated Flow Transition and Heat Transfer Around a Two-Dimensional Rib

2007 ◽  
Vol 73 (725) ◽  
pp. 260-267
Author(s):  
Hideki YANAOKA ◽  
Takao INAMURA ◽  
Reiri KOBAYASHI
1971 ◽  
Vol 93 (4) ◽  
pp. 342-348 ◽  
Author(s):  
John W. Mitchell

An experimental investigation of the heat transfer from the base of a two-dimensional wedge-shaped body to the separated-flow region was conducted in a low-speed wind tunnel. The Stanton number has been determined as a function of Reynolds number for two geometries that are representative of heat-exchanger surfaces. The heat transfer is found to be comparable in magnitude to that for attached flows. An analysis based on the mechanisms of vortex shedding and boundary-layer behavior is developed. The analysis agrees fairly well with the data and indicates the parameters governing base heat transfer.


Author(s):  
Yassine Slatni ◽  
Mahfoud Djezzar ◽  
Tarek Messai ◽  
Mahfoud Brahim

Inside a greenhouse, during the day, the temperature rises very quickly, while the plants have to face temperatures that rise to more than 35[Formula: see text]C. The plant closes its pores to limit sweating and stops growing. As soon as it gets hot, it is therefore necessary to ventilate the greenhouse. In this context, this research aims to investigate the behavior of the natural ventilation on the internal climate of the tunnel greenhouse, which contains two openings in the roof. The effect of the position of the openings on heat transfer is considered, thus promoting photosynthesis and plant growth. The vorticity transport equation, the Poisson equation and the energy equation are discretized by using the finite volume method. Two-dimensional simulations that described laminar flows in a steady state were carried out. Flows are studied for a range of parameters: the Rayleigh number, Ra, [Formula: see text], and three positions of opening ventilation. The results reveal that the ventilation through the top opening position allows the best creation of heat exchanges between the air inside the greenhouse and its atmosphere, which serves to conserve the plant under a favorable climate that allows its growth.


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