Assessment of the parameters of surface friction with the methods of the experiment design theory

A mathematical model is constructed of the dependences of the coefficient of permeable-wall surface friction with heat-and-mass transfer on various factors (flow speed, parameter of equivalent sand roughness, plate thickness, gas-film lubrication, and others). The model is based on the results of research conducted using the polyfactorial experiment method. The key feature of this method is the polyfactorial approach to implementation of the experiment because it changes all the operating factors simultaneously point-by-point, rather than changing them in succession. The novel polyfactorial experiment design method enables us to select for experimentation the most informative combinations of values of the significant factors and to determine the number of experiments necessary and sufficient to obtain an analytical dependence of the surface friction coefficient with the required accuracy.