Dynamic-mesh Cfd and Its Application to Flapping-wing Micro-air Vehicles

We are currently developing new numerical simulation methods and computational fluid dynamics (CFD) codes designed for advanced fluid-structure interaction (FSI) applications that have moving mechanical components and/or changing domain shapes. The method is called Dynamic-Mesh (DM) and is currently being implemented in parallel within our XFlow CFD simulation code. This method involves the tight coupling of automatic mesh generation (AMG) technology with more traditional parallel CFD methods designed for unstructured meshes. By coupling these two distinct technologies together, the mesh generation process never stops and continues throughout the entire simulation. By doing this, we can define a so-called “dynamic” mesh that has the ability to adjust, change, and modify its structure in response to any changes in geometry or other factors. DM-CFD technology of XFlow can be used to model the fluid flow around or within flapping-wing vehicles, rotorcraft, engines, turbines, pumps, airdrop systems, and has applicability to modeling free-surface flow, fluid-particle flow, energy/nuclear systems, and many bio-medical applications. Traditionally, these are some of the most difficult applications to simulate. We are currently demonstrating and testing the DM technique and the capabilities of XFlow through a series of complex FSI applications. These applications include the simulation of airdrop systems involving the deployment (i.e. opening) of parachutes, bio-medical applications, and the simulation of micro air vehicles (MAV) and biological systems. Results of the modeling of a flapping-wing MAV will be highlighted here to demonstrate the capabilities and potential of the DM method in XFlow, as well as providing some illusrative results for an interesting application.