The calculation of the peristaltic pump characteristics taking into account the roughnesses on the internal surface of the working member

In the introduction of the work the short review of the literature, devoted to the miniature peristaltic pumps and also to the studies of the influence of the roughness in the microchannels with the laminar flow, is presented. The presented calculation procedure of the pump characteristics is based on the usage of the Bernoulli equation and the interpretation of the pump working member sections with the roughness as the local hydraulic resistances. The losses in these sections are expressed in the equivalent length which has been counted by performing the numerical experiments in the program STAR-CCM+. As have shown by the numerical experiments, the equivalent length of such sections is the function of a Reynolds number and the geometrical parameters of the roughness of the surface of the pump working member. For calculations the axisymmetric roughness with the profiles is in the form of the isosceles triangles and the rectangular triangles have been chosen. The calculation for the roughness in the form of rectangular triangles was performed in such a manner that when the fluid flows in the direction of the pressure pipeline it represented the repeating confusers and the sudden enlargements, and when flow takes place in the opposite direction - diffusors and sudden contractions. The numerical calculation has shown that in such case an energy loss with the flow in the opposite direction is bigger, but only with the certain geometrical parameters of the roughness. It was considered, that the roughness are only in the beginning and in the end of the pump working member (tube), and in the compression region the surface is smooth. As a calculations result the pump’s pressure characteristics for both tube without the sections with the roughness and the tube with these sections were constructed. The results gained with the offered technique have shown good enough coincidence to the results of the numerical experiments

peristaltic pump, laminar flow, computational hydrodynamics