Effect of Pressure Gradient on the Evaporation Rate from a Horizontal Water Panel.

Document Type : Research Studies

Author

Mechanical Power Engineering Department, Faculty of Engineering, Mansoura University, Mansoura, Egypt.

Abstract

The rate of evaporation from a water panel to air flow in a wind tunnel is investigated experimentally. A turbulent air is flowed in a rectangular duct (11000<Re<51670). Wedges are fixed on the inner vertical walls of the test section above the water panel. The influence of area ratio parameter (β) on the evaporation rate and hence the mass transfer coefficient is considered at different values of Reynolds number. The results show that. Sherwood number increases with increasing Reynolds number for both negative and positive pressure gradient. Also, Sherwood number increases with increasing the area ratio parameter, which is proportional to the pressure gradient for all values of Reynolds number in case of convergent configuration. But it decreases with the increase in positive pressure gradient in case of divergent configuration. The maximum enhancement in mass transfer coefficient in case of negative pressure gradient is 297% at Re=11000 and B=0.06898. An empirical correlation for Sherwood number as a function of Reynolds number, Schmidt number and area ratio parameter for the considered operating conditions are obtained.

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