Towards Numerical Simulation of Flapping Foils on Fixed Cartesian Grids

Flapping foils found in nature such as bird and insect wings and fish fins are being studied for potential use in micro aerial vehicles and autonomous underwater vehicles. The fluid dynamics associated with these foils is extremely complicated and much remains to be learnt in this arena. Experimental investigations of flapping foils in nature are limited by their inability to provide full-field, spatially and temporally resolved, velocity and pressure measurements. Many of the limitations can be alleviated with computational fluid dynamics techniques. Computational analysis of these flows is however, by no means an easy proposition due to the many inherent complexities in these flows. These include a wide variety of flow conditions and the presence of flexible moving boundaries. In the current paper, we describe a Cartesian grid based immersed boundary flow solver which is being developed to handle such flows. The paper describes the salient features of the numerical approach along with examples that illustrate its capabilities.