Diastolic flow in a left ventricle physical model from Arvind Santhanakrishnan on Vimeo.

Streamlines of diastolic filling flow in a flexible-walled anatomical left ventricle physical model incorporated into a pulsatile flow circuit.

Intraventricular filling flow in obstructive hypertrophic cardiomyopathy, from Arvind Santhanakrishnan on Vimeo.

Intraventricular flow in a physical model of obstructive hypertrophic cardiomyopathy, at heart rate of 110 bpm. Flow visualized using particle image velocimetry (PIV). Contours indicate vorticity (rotation strength) of the flow, and arrows correspond to the 2D velocity vector field.

Upside-down jellyfish pulsing in background flow from Arvind Santhanakrishnan on Vimeo.

Interaction of upside-down jellyfish currents with background flow, filmed at the Applied Fluid Mechanics Lab, Oklahoma State University. Pink dye is introduced left of the video frame near the sandy substrate. The dye is pulled toward the medusa by pulsations of the bell . The branched oral arms of the jellyfish break the coherent starting vortex formed during bell contractions, and effectively mix the dye with the incoming background flow moving left to right.

Intraventricular flow at increased heart rate (110 bpm) from Arvind Santhanakrishnan on Vimeo.

Particle image velocimetry (PIV) data acquired on left ventricle model at the Applied Fluid Mechanics Lab @ Oklahoma State University. Contours indicate vorticity (rotation strength) of the flow, and arrows correspond to the 2D velocity vector field.

Clap and fling simulator from Arvind Santhanakrishnan on Vimeo.

Top view of the 'clap and fling' wing-wing interaction simulated using a robotic model for studies of tiny insect flight at low Reynolds numbers.

Bell motion of upside-down jellyfish from Arvind Santhanakrishnan on Vimeo.

High-resolution video of bell pulsations of upside-down jellyfish filmed at the Applied Fluid Mechanics Lab, Oklahoma State University. Swirling motion of particles mixed in water is seen near bell margin.

Flapping flight with bristled wings from Arvind Santhanakrishnan on Vimeo.

Physical models of bristled wings in 'clap and fling' interaction for studies of tiny insect flight at low Reynolds numbers.

Ghost shrimp swimming from Arvind Santhanakrishnan on Vimeo.

High-speed video (600 frames per second) of a ghost shrimp individual (1.5 inches body length) showing deformation of individual swimming limbs and their relative non-synchronous stroke pattern. A tail-to-head metachronal wave is generated in the same direction as the animal motion (right to left).

Ghost shrimp hovering from Arvind Santhanakrishnan on Vimeo.

Hovering of a freshwater ghost shrimp individual (~1.5 inches body length) was filmed at 600 frames per second at the Applied Fluid Mechanics Lab, Oklahoma State University.