CFD Simulations of Viscous Heating in a Spiral-Channel Micropump

In this work, the influence of viscous heating on the flow performance of a spiral-channel viscous micropump was investigated numerically using finite volume method (FVM). A number of 3D models for the spiral-channel micropump boundary conditions and using different working fluids (Glycerin, and water) were built and analyzed by considering the change of the fluid viscosity as a function of temperature. Results showed that significant temperature rises due to viscous heating are obtained, and the error in calculating the volumetric flow rate by considering viscous heating term is increased with increasing Re.Eu, and reaches 10% for the spiral wall condition and 40% for the single wall condition at Re.Eu = 1.5. Also, it was found that large deviations from the analytical predictions are obtained for high viscous fluids, and that viscous heating and temperature rise in the stationary wall condition is higher than that in the spiral wall condition. As a conclusion, viscous heating in the spiral-channel micropump is too significant to be neglected and affects the temperature, pressure, and velocity distribution of the flow field.