•  
  •  
 

Corresponding Author

Mostafa, Hesham

Subject Area

Mechanical Power Engineering

Article Type

Original Study

Abstract

Evaporation rate of water into air flow over water panel which fixed in the floor of a rectangular wind tunnel is investigated, experimentally. Flow passage area variation is constructed by fixing wedges in the ceiling of the test section; in front of water panel. Two configurations are achieved for passage in the section; convergent configuration and divergent configuration. Convergent configuration increases air velocity accordingly there is a negative pressure gradient, and Convergent configuration decreases air velocity accordingly there is a positive pressure gradient. The required measurements for velocity, temperature and humidity, are taken at upstream and downstream over the water panel. Also, the amount of water evaporated through each experiment was measured. The effect of flow passage area variation of the evaporation rate is investigated at different values of Reynolds number and its impacts on Sherwood number are considered. The rang tested for Reynolds number is (4000>Re>11000). The obtained experimental results show that, Nusselt and Sherwood numbers increases with increasing Reynolds number for both convergent and divergent configuration. Sherwood number takes higher values in case of convergent configuration than the divergent configuration. The maximum enhancement in Nusselt about 150% and Sherwood numbers is about 140%at Re=11446 and area ratio parameter (β=1.05) in the considered operating ranges. Empirical correlations for Nusselt and Sherwood numbers as a function of Reynolds number, Prandtl and Schmidt numbers. Evaporation rate of water into air flow over water panel which fixed in the floor of a rectangular wind tunnel is investigated, experimentally. Flow passage area variation is constructed by fixing wedges in the ceiling of the test section; in front of water panel. Two configurations are achieved for passage in the section; convergent configuration and divergent configuration. Convergent configuration increases air velocity accordingly there is a negative pressure gradient, and Convergent configuration decreases air velocity accordingly there is a positive pressure gradient. The required measurements for velocity, temperature and humidity, are taken at upstream and downstream over the water panel. Also, the amount of water evaporated through each experiment was measured. The effect of flow passage area variation of the evaporation rate is investigated at different values of Reynolds number and its impacts on Sherwood number are considered. The rang tested for Reynolds number is (4000>Re>11000). The obtained experimental results show that, Nusselt and Sherwood numbers increases with increasing Reynolds number for both convergent and divergent configuration. Sherwood number takes higher values in case of convergent configuration than the divergent configuration. The maximum enhancement in Nusselt about 150% and Sherwood numbers is about 140%at Re=11446 and area ratio parameter (β=1.05) in the considered operating ranges. Empirical correlations for Nusselt and Sherwood numbers as a function of Reynolds number, Prandtl and Schmidt numbers.

Keywords

heat and mass transfer; humidification; moist air; duct flow

Download

Share

COinS