Influence of polymers on flow and heat transfer due to peristaltic waves: a molecular approach

Abstract

This work aims to have an insight into the effects of polymers on flow and heat transfer due to peristaltic waves. Oldroyd-B model, based on kinetic theory, is considered to study the relation between the molecular structure of the polymers and the rheological properties. The main advantage of using this model is the inclusion of information based on molecular structure. Such inclusion in stress tensor incorporates the effects of stretching and orientation of the molecules. Some significant applications polymer-peristalsis can be found in tissue engineering, intake of food, and medicines. Approximations of long-wavelength and low Reynolds number are used to investigate the main features of the problem. Pressure gradient, velocity, temperature, trapped bolus, drag coefficient, and heat flux at the wall are studied numerically. The analysis is based on the change in important parameters like polymer concentration, relaxation time, Weissenberg number, and Brinkman number. Results show that by increasing polymer concentration parameter, Weissenberg number, and relaxation time parameter, the negative pressure gradient in the flow geometry increases. By increasing the polymer concentration parameter and time relaxation parameter, the velocity and temperature profiles increase. An increase in polymer concentration increases the size of the trapped bolus. Drag parameter at the wall decreases while heat flux increases when polymer concentration and Weissenberg number are increased.