An Interferometric Technique for Temperature and Concentration Measurement for an Air-Water Interface

1971 ◽  
Vol 93 (2) ◽  
pp. 185-190
Author(s):  
C. Prasad ◽  
C. S. Chen ◽  
J. T. Beard
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Water System ◽  
Lewis Number ◽  
Ambient Air ◽  
Water Interface ◽  
Interferometric Technique ◽  
Air Water Interface ◽  
A New Technique ◽  
Simultaneous Heat

A new technique for the measurement of temperature and concentration for a simultaneous heat and mass transfer analysis is described. The technique employs a one wavelength Mach-Zehnder interferometer with an additional noninterferometric measurement of temperature or concentration. This overcomes the difficulties encountered in other interferometric techniques used for simultaneous heat and mass transfer analysis such as two wavelength technique and one wavelength technique with the assumption of Lewis number being unity. Computational formulas were developed, by which either temperature or concentration can be calculated from the interferograms. An air-vapor boundary layer formed due to heated water and ambient air set in parallel flow was analyzed with this technique. Better results in the air-water system were obtained for the concentration from interferogram analysis with the temperature measured by another technique.

Simultaneous Heat and Mass Transfer From a Two-Dimensional, Partially Liquid-Covered Surface

1991 ◽  
Vol 113 (4) ◽  
pp. 874-882 ◽  
Author(s):  
Y.-X. Tao ◽  
M. Kaviany
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Reynolds Number ◽  
Surface Temperature ◽  
Heat And Mass Transfer ◽  
Solid Surface ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Ambient Air ◽  
Simultaneous Heat

Simultaneous heat and mass transfer from partially liquid-covered surfaces is examined experimentally using a surface made of cylinders with the voids filled with liquid. The steady-state evaporation rate, surface temperature of the liquid and exposed solid, and location of meniscus are measured for various ambient air velocities and temperatures. Using these, we examine the effect of the extent to which the liquid covers the surface on the evaporation mass transfer rate resulting from the convective heat transfer from the ambient gas to this surface. The results show strong Bond and Reynolds number effects. For small Bond and Reynolds numbers, the presence of dry (exposed solid) surface does not influence the mass transfer rate. As the Bond or Reynolds number increases, a critical liquid coverage is found below which the mass transfer begins to decrease. Heat transfer from the exposed solid to the liquid is also examined using the measured surface temperature, a conduction model, and an estimate of the liquid and solid surface areas (using a static formation for the liquid meniscus). The results show that at the liquid surface an analogy between heat and mass transfer does not exist.

Simultaneous Heat and Mass Transfer in Inclined Channel With Asymmetrical Conditions

2010 ◽  
Author(s):  
Othmane Oulaid ◽  
Brahim Benhamou ◽  
Nicolas Galanis
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Mass Fraction ◽  
Numerical Study ◽  
Water Film ◽  
Ambient Air ◽  
The Body ◽  
Parallel Plates ◽  
Inclined Channel ◽  
Simultaneous Heat

This work deals with a numerical study of simultaneous heat and mass transfer with phase change in an inclined channel formed by two parallel plates. The lower one is covered by a thin liquid water film and the upper one is considered impermeable. The plates are maintained at a constant temperature TW. Ambient air with uniform dry bulb temperature Tin and relative humidity φin enters the channel with a uniform upward velocity Uin. The liquid film is assumed to be extremely thin and its temperature is equal to the wall temperature. Steady state conditions are considered and the flow is assumed to be laminar. Viscous dissipation, radiation heat transfer and other secondary effects (pressure work, energy transport by the inter-diffusion of species, Dufour and Soret effects) are neglected. The physical properties are taken constant except for the density in the body forces, which is considered to be a linear function of temperature and mass fraction. Results show that buoyancy forces have an important effect on the hydrodynamic, thermal and mass fraction fields and this effect depends on the channel inclination. A flow reversal chart and analytical correlations for the corresponding critical values of the thermal and solutal Grashof numbers are presented for different channel inclinations.

Simultaneous heat and mass transfer during evaporation from a film of liquid into the turbulent gas

1982 ◽  
Vol 47 (3) ◽  
pp. 766-775 ◽  
Author(s):  
Václav Kolář ◽  
Jan Červenka
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Driving Forces ◽  
Proper Definition ◽  
Definition Of ◽  
Simultaneous Heat ◽  
Theory And Experiment

The paper presents results obtained by processing a series of published experimental data on heat and mass transfer during evaporation of pure liquids from the free board of a liquid film into the turbulent gas phone. The data has been processed on the basis of the earlier theory of mechanism of heat and mass transfer. In spite of the fact that this process exhibits a strong Stefan's flow, the results indicate that with a proper definition of the driving forces the agreement between theory and experiment is very good.

Simultaneous Heat and Mass Transfer in Free Convection

1957 ◽  
Vol 49 (6) ◽  
pp. 961-968 ◽  
Author(s):  
W. G. Mathers ◽  
A. J. Madden ◽  
Edgar L. Piret
Keyword(s):  
Mass Transfer ◽  
Free Convection ◽  
Heat And Mass Transfer ◽  
Simultaneous Heat
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