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Heat and mass transfer from or to a horizontal moving water film to airflow flowing over the film inside a rectangular duct wind tunnel is investigated, experimentally. To perform the experimental study for this phenomenon air flows inside a rectangular duct over a moving water film flow inside the duct, which is fixed in the floor of the tunnel. Therefore, some of the water film is evaporated from the water surface to the air flowing over it. The following measurements for velocity of moist air and water, temperature, humidity, are taken at five positions along test section and upstream of the water panel. Also, the amount of water evaporated through each experiment is measured. The results show that, Nusselt and Sherwood numbers increase with increasing Reynolds number. Comparison between the obtained results and the previous works show good agreement.

Heat and mass transfer between a horizontal moving water film and air flowing over the film is theoretically investigated. In the present theoretical model, the flow of air over the moving water film is assumed to be laminar and steady in Cartesian coordinates. The governing equations are the continuity, momentum, energy and concentration equations. These governing equations set of equations to determine the distribution of the dimensionless velocity, temperature are in a dimensionless form. By introducing new proper independent and dependent variables, the governing equations are transformed to a set of dimensionless differential equations. A computer program in FORTRAN language is developed to solve this and concentration. Also, local values of Nusselt and Sherwood numbers for different values of Reynolds number are calculated. Comparison between the obtained results and the previous works show good agreement. The results show that, Nusselt and Sherwood numbers increase with increasing Reynolds number.

Thermal performance of a flat heat pipe cooling system is experimentally investigated. Pure water and Al2O3-water based nanofluids are used as working fluids. An experimental setup is designed and constructed to study its performance under different operating conditions. The effect of working fluid, filling ratio, volume fraction of nano-particle in the base fluid, and heat input rate on the average heat transfer coefficient and in turn the average Nusselt number are investigated. Total thermal resistance of the heat pipe for pure water and Al2O3-water based nanofluid are also predicted. Correlation is obtained to predict the influence of Prandtl number, filling ratio and dimensionless heat coefficient, Kq for Nusselt number. Results showed that the average heat transfer coefficient, using Al2O3-water based nanofluid enhanced by 10.5% up to 37% compared to that of pure water, depending on filling ratio and volume fraction of nano-particles in the base fluid. The experimental data are compared with the available literature and discrepancies between results are discussed.