Numerical Simulation of Viscoelastic Flows through Periodic Undulating Channels

Abstract

Viscoelastic flows through periodic undulating channels were numerically simulated with the HSMAC method by using the modified Giesekus model. The results obtained with a variety of the modified Giesekus fluids show the increment of flow resistance: the occurrence of excess pressure loss. The degree of the excess pressure loss depends on the stretch-thickening property of elongational viscosity as well as the amplitude and wavelength of undulating channel. The streamlines after the occurrence of the excess pressure loss indicate a significant swell in the expansion part because of the Barus effect. The distributions of stress power are presented in order to discuss the mechanism of the occurrence of the excess pressure loss, and the connection with stress relaxation property of the fluids is pointed out.