Satish Kumar Chimakurthi

Bio: Satish Kumar Chimakurthi is an academic researcher from University of Michigan. The author has contributed to research in topics: Aerodynamics & Wing. The author has an hindex of 10, co-authored 18 publications receiving 1190 citations. Previous affiliations of Satish Kumar Chimakurthi include Imperial College London & Ansys.

Computational Aeroelasticity Framework for Analyzing Flapping Wing Micro Air Vehicles

Abstract: Because of their small size and flight regime, coupling of aerodynamics, structural dynamics, and flight dynamics are critical for micro aerial vehicles This paper presents a computational framework for simulating structural models of varied fidelity and a Navier-Stokes solver, aimed at simulating flapping and flexible wings The structural model uses either 1) the in-house developed UM/NLABS, which decomposes the equations of 3-D elasticity into cross-sectional and spanwise analyses for slender wings, or 2) MSCMarc, which is a commercial finite-element solver capable of modeling geometrically nonlinear structures of arbitrary geometry The flow solver employs a well-tested pressure-based algorithm implemented in STREAM A NACA0012 cross-sectional rectangular wing of aspect ratio 3, chord Reynolds number of 3 x 10 4 , and reduced frequency varying from 04 to 182, with prescribed pure plunge motion is investigated Both rigid and flexible wing results are presented, and good agreement between experiment and computation are shown regarding tip displacement and thrust coefficient Issues related to coupling strategies, fluid physics associated with rigid and flexible wings, and implications of fluid density on aerodynamic loading are also explored in this paper

Computational modeling of spanwise flexibility effects on flapping wing aerodynamics

Abstract: The implications of spanwise flexibility on flapping wing aerodynamics are investigated numerically for a rectangular wing in pure heave A computational framework for fluidstructural interactions has been developed based on a direct coupling procedure between (i) a pressure-based finite-volume fluid flow solver based on the Navier-Stokes equations, and (ii) a quasi-3D finite element structural dynamics solver based on a geometrically nonlinear composite beam-like and linear plate-like formulations The computational results are first correlated with available experimental data It is shown that two key factors associated with spanwise wing deformation affect thrust generation, namely, in-phase motion between the wing tip and root, and the increased effective angle of attack of the deformed wing If the wing motions resulting from both prescribed motion and deformation are correlated, the increased effective angle of attack at the tip could enhance the aerodynamic performance If the flexibility is too high, then the wing tip and root could move in inconsistent directions, resulting in deteriorated aerodynamic performance

A computational and experimental study of flexible flapping wing aerodynamics

Abstract: To gain some more understanding of the flapping wing aerodynamics and aeroelasticity associated with biological flyers and micro air vehicles (MAVs), a combined computational and experimental study of a well characterized flapping wing structure was conducted. In particular, the coupling between aerodynamics and structural dynamics plays an important role in such flyers but to date has not been adequately addressed. An aeroelasticity framework based on a co-rotational shell finite element solver with a Navier-Stokes solver is developed. Experimentally, a customized digital image correlation system measures the wing deformation, a load sensor attached to the flapping mechanism records the forces produced by the flapping motion, and a stereo digital particle image velocimetry measures the flow velocities. Computational efforts with insight into the fluid physics are reported. Relevant fluid physics are documented including the counter-rotating vortices at the leading and the trailing edge which interact with the tip vortex during the wing motion. Overall, good correlations between experiment and computation are attained. Furthermore, studies on hypothetical flexible flapping wing configurations showed that wing flexibility can be tailored to alter the aerodynamics of a flapping wing.

Flapping Wing CFD/CSD Aeroelastic Formulation Based on a Co- rotational Shell Finite Element

Abstract: Flexible flapping wings have garnered a large amount of attention within the micro aerial vehicle (MAV) community: a critical component of MAV flight is the coupling of aerodynamics and structural dynamics. This paper presents a computational framework for simulating shell-like wing structures flapping in incompressible flow at low Reynolds numbers in both hover and forward flight. The framework is developed by coupling an in-house co-rotational finite element structural dynamics solver suitable for small strain and large rotations, to an in-house pressure-based Navier-Stokes solver. The development of the computational structural dynamics (CSD) solver and its coupling with the computational fluid dynamics (CFD) solver is discussed in detail. Validation studies are presented for both the CSD and the aeroelastic solvers using different wing configurations. Structural dynamics solutions are presented for rectangular wings with either a prescribed plunge or a single degree-of-freedom flapping motion. The aeroelastic response is computed for two different wing configurations: 1) a thin-plate rectangular aluminum wing (aspect ratio 6) undergoing a single-axis large amplitude flapping motion and 2) a rectangular wing of NACA0012 cross-section (aspect ratio 6) under a pure plunge motion. Results are validated against available experimental data and those obtained from a different aeroelasticity framework previously developed by the authors.

A Review of Morphing Aircraft

Abstract: Aircraft wings are a compromise that allows the aircraft to fly at a range of flight conditions, but the performance at each condition is sub-optimal. The ability of a wing surface to change its geometry during flight has interested researchers and designers over the years as this reduces the design compromises required. Morphing is the short form for metamorphose; however, there is neither an exact definition nor an agreement between the researchers about the type or the extent of the geometrical changes necessary to qualify an aircraft for the title ‘shape morphing.’ Geometrical parameters that can be affected by morphing solutions can be categorized into: planform alteration (span, sweep, and chord), out-of-plane transformation (twist, dihedral/gull, and span-wise bending), and airfoil adjustment (camber and thickness). Changing the wing shape or geometry is not new. Historically, morphing solutions always led to penalties in terms of cost, complexity, or weight, although in certain circumstances, thes...

Mechanics of composite materials

Abstract: 1.Introduction to Composite Materials 2. Macrochemical Behavior of a Lamina 3.Micromechanical Behavior of a Lamina 4.Macromechanical Behavior of a Laminate 5.Bending, Buckling, and Vibration of Laminated Plates 6.Other Analysis and Behavior Topics 7.Introduction to Design of Composite Structures Appendix A.Matrices and Tensors Appendix B.Maxima and Minima of Functions of a Single Variable Appendix C.Typical Stress-Strain Curves Appendix D.Governing Equations for Beam Equilibrium and Plate Equilibrium, Buckling, and Vibration Index