Two-dimensional simulations of valveless pumping using the immersed boundary method

Flow driven by pumping without valves is examined, motivated by biomedical applications: cardiopulmonary resuscitation (CPR) and the human fetus before the development of the heart valves. The direction of flow inside a loop of tubing which consists of (almost) rigid and flexible parts is investigated when the boundary of one end of the flexible segment is forced periodically in time. Despite the absence of valves, net flow around the loop may appear in these simulations. The magnitude and even the direction of this flow depend on the driving frequency of the periodic forcing.