IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Multi-megawatt wind turbines that are increasingly being used for higher and cheaper wind power generation have large, slender and extremely flexible rotor blades made of advanced composite materials. Safe and efficient design of these rotors requires an accurate modeling of the blade aeroelastic response under real wind conditions to include the effect of blade flexibility. This paper presents the results of the numerical simulations of the flow field around a 3-bladed horizontal axis wind turbine rotor and the blade aeroelastic response using a coupled computational fluid dynamics (CFD) and finite element analysis (FEA) approach. The blade has a NACA64 profile with a box-spar stiffener. The wind shear along the blade span and the effect of wake turbulence is included in the unsteady aerodynamic load calculation. The velocity field ahead and in the rotor wake is obtained for different mean wind speeds at the inlet. The time history of the flap-wise blade deformations is computed at different span locations. The wake turbulence was investigated by computing the turbulence intensity. Copyright © 2013 APCWE-VIII. All rights reserved. Publishedby Research Publishing, Singapore.

Department of Aerospace Engineering

Proceedings of the 8th Asia-Pacific Conference on Wind Engineering, APCWE 2013

CFD-FEA coupled simulation of the dynamic aeroelastic response of a large scale horizontal axis wind turbine rotor

The residual strength estimation of thin-walled pressurized shell structures is of relevance to pressurized thin piping systems and aged airframes for life extension programs. This requires powerful and efficient computational techniques using finite element method and numerical fracture mechanics for elastic or inelastic stress analysis and crack growth simulation. For this purpose, detailed modeling and finite element mesh generation of built-up structures like stiffened cracked thin shells is necessary and it is a computationally intensive task. Automating the entire process from geometric modeling to stress analysis and crack growth simulation (requires remeshing) vastly improves the efficiency of the computational analysis and reduces the chances of modeling and simulation errors. A geometric primitive based technique has been developed for automated modeling and meshing. The work is carried out primarily on aged fuselage shell panels but the method is applicable to other pressurized thin piping systems. This paper presents a simple and efficient computational procedure using a geometry based logic and surface mesh generation technique for automated modeling and crack growth simulation in pressurized thin-walled shells. The approach has been used to develop a structural integrity evaluator software. Finite element analysis is carried out using a commercial software, and these results are fed to the structural integrity evaluator. Some results of the nonlinear finite element analysis and elastic-plastic stable crack growth simulation in pressurized stiffened fuselage panels using this approach are presented.