A NEW METHOD FOR MEASURING INSTANTANEOUS AND LOCAL MASS TRANSFER RATE

Abstract

A new method for measuring instantaneous and local mass transfer rate is established by observing a rate of conductive heat transfer inside a solid with mass transfer by means of a thin-film resistance thermometer. The principle of the method, the instruments and the procedure are described. To verify the measuring method experimentally, we measured the rate of vaporization of an organic solvent from a porous flat plate surface into an air stream. The experimental results are in good agreement with the previously reported results in the range of the Reynolds number Re= 10³4×10⁴ for laminar and turbulent boundary layers. The experimental error is estimated to be at most about ±10% and the response time to be about 10μ sec. This method may contribute a great deal to the analysis of various instantaneous phenomena in unsteady and transient states as well as in steady states.