40.4 Saturday, Jan. 5 Tubular heart pumping in tunicates and other invertebrates. BAIRD, A.J.*; MILLER, L.A.; Univ. of North Carolina, Chapel Hill email@example.com
Valveless tubular hearts transport hemolymph in many invertebrates with open circulatory systems. Tunicates such as Ciona intestinalis rely on bidirectional valveless pumping through a U-shaped heart tube. Research related to valveless fluid transport has described pumping in tubular hearts as either peristalsis (characterized by a linear frequency-flow relationship and active contractions down the length of the tube) or dynamic suction pumping (characterized by a nonlinear frequency-flow relationship and a localized region of active contraction). The immersed boundary method will be used to simulate the fully-coupled fluid-structure interaction problem. Corresponding experiments will be performed using dynamically scaled physical models of peristalsis and dynamic suction pumping. Womersley number and other parameters will be matched to the heart tube of Ciona intestinalis and other tunicates. The fluid transport efficiencies of each mechanism will be described over this parameter space. A new pumping mechanism that includes features of both traditional peristalsis and dynamic suction pumping will be introduced that incorporates the electrophysiology of the tubular heart.