Mathematical models for coating processes

摘要: The flow is considered of a Newtonian fluid, viscosity η and surface tension T, in the narrow gap between pair rollers radii R1 R2, whose peripheral speeds are constant equal to U1 U2 respectively. objective determine coating thickness h1∞ on upper roller as function non-dimensional parameters H0/R, ηU/T U1/U2, where H0 minimum thickness, U = ½(U1 + U2), 2R−1 R1−1 R2−1.Using lubrication theory provide an adequate description fluid flow, two mathematical models derived essential difference lies specification boundary conditions. In separation model it assumed that pressure distribution will terminate at position which both stagnation point separation, whereas Reynolds incorporates classical each case, theoretical predictions for h1∞/H0 U1/U2 found compare well with experiment. However, does suggest applicable different complementary regions parameter space, hence together they may form basis further investigations into various features processes.