Laminar Flow in Porous Tubes at High Extraction Rates

摘要

It is shown that stable mathematical solutions exist at high extraction rates. Both approximate and exact solutions (within computer accuracy) are derived. In order to obtain these results in practice it is necessary for the wall Reynolds Number, based on the extraction velocity, to be greater than approximately 40. This severely limits the tube lengths to which the results apply if the axial Reynolds Number is to be below 3000, the normal limit of laminar flow. However, it is suggested that high rates of extraction may remove the boundary layer rapidly enough to promote laminarization at much higher Reynolds Numbers and thus increase the range of practical importance of the results. (Author)