Adaptive Cartesian/Immersed Interface Methodology for Micro Air Vehicle Flow Control with Electro-Hydrodynamic Forces

The design of future Micro Air Vehicles (MAVs) requires detailed understanding of unsteady flows around flexible lifting surfaces with strong interactions between separation and transition at low Reynolds numbers. Since flexure often involves large deformations exceeding the Kolmogorov scale by orders-of-magnitude, methods employing moving and deforming computational grids may require excessive re-meshing to prevent unacceptable grid distortion. The goal of this project is to develop a computational capability that combines the benefits of Cartesian mesh with Adaptive Mesh Refinement (AMR) and Immersed Interface Method (IIM) for Direct Numerical Simulations (DNS) of separation and transition over flexible moving surfaces avoiding prohibitively expensive re-meshing. This new hybrid AMR-IIM approach will enable dynamic grid adaptation to flow physics down to the Kolmogorov scale. In Phase I, the feasibility of the AMR-IIM approach will be demonstrated for hovering wings with prescribed flexure. Initial studies of flow control concepts combining wing flexibility with electro-hydrodynamic forces will be performed. Phase II efforts will focus on adding a Fluid-Structure Interaction (FSI) capability for modeling aeroelastic effects, developing plasma flow control capabilities and code parallelization for large scale simulations. Innovative concepts of flow control over flexible flapping wings with electro-hydrodynamic forces and plasmas will be tested and demonstrated. BENEFIT: The computational tool developed in this project will be used to understand flow features and analyze innovative flow control concepts for Micro Air Vehicles with flapping wings. It will be useful to better understand the physics of insect flight, molecular motors designed by nature, and future smart nanomachines. Other applications include a wide range of aerospace, defense and biomedical applications where moving surfaces and the resolution of fine flow features and boundary layer flows is important. These include, aircraft maneuvering and store separation, missile maneuvering (moving fins), heart valves and many other biomedical applications.