Steady secondary flows of Phan-Thien-Tanner fluids in the vicinity of a corner

Secondary flows of Phan-Thien-Tanner fluids in channels formed by two intersecting walls, and driven by a pressure gradient parallel to the intersection line, are studied by means of perturbation analysis, where the perturbing parameter is the relaxation time. The velocity field is analysed in relation to the opening angle and distance from the comer within the fluid region. An analytically exact solution is found at 0(λ³), through the mathematical structure of which is possible to draw some general and important conclusions about the dynamics of the transversal flow. Such results are of potential interest in the design of devices aimed at exploiting the transport capacity of secondary flows.