A new method for the experimental determination of Lewis' relation

The Lewis relation is an important part of the equations that govern simultaneous heat and mass transfer processes that take place in many engineering devices. Usually, the assumption is made that the value of Lewis relation is equal to 1 which is not always realistic. As result, a new method is presented for evaluation of Lewis relation. This method is then used to evaluate Lewis relation in the case of the flow of free air stream over a flat planar test specimen. The flat planar materials used to demonstrate the method in this work is made out of two different materials, bleached paper and bleached paper/Na-silicate.