The effects of variation of blade torsion frequency on rotor performance and structural loads are investigated for a 1/rev active flap rotor and baseline rotor (no active control). The UH-60A four-bladed articulated main rotor is studied at a high-speed forward flight condition. The torsion frequencies are varied by modifying the spanwise torsional stiffness of the blade and/or the pitch link s...

ABSTRACT Blade failure is a common problem of a steam turbine and it’s failure in-service results in safety risks, repair cost and non operational revenue losses. Thus, the reliability of these blades is very important for the successful operation of a steam turbine. Dynamic analysis of a steam turbine blade in computational environment is carried out in the present work. In order to gain physi...

The present paper aims at describing and comparing different small Vertical Axis Wind Turbine (VAWT) architectures, in terms of performance and loads. These characteristics can be highlighted by resorting to the Blade Element-Momentum (BE-M) model, commonly adopted for rotor pre-design and controller assessment. After validating the model with experimental data, the paper focuses on the analysi...

Title of Dissertation: CFD Based Unsteady Aerodynamic Modeling for Rotor Aeroelastic Analysis Jayanarayanan Sitaraman, Doctor of Philosophy, 2003 Dissertation directed by: Associate Professor James D. Baeder Department of Aerospace Engineering A Computational Fluid Dynamics (CFD) analysis is developed for 3-D rotor unsteady aerodynamic load prediction. It is then coupled to a rotor structural a...

The effectiveness of surrogate modeling of helicopter vibrations, and the use of the surrogates for optimization of helicopter vibration are studied. The accuracies of kriging, radial basis function interpolation, and polynomial regression surrogates are compared. In addition, the surrogates for the vibratory hub shears and moments are used to generate an objective function which is employed in...

The effects of variation of blade torsion frequency on rotor performance and structural loads are investigated for a 1/rev active flap rotor and baseline rotor (no active control). The UH-60A four-bladed articulated main rotor is studied at a high-speed forward flight condition. The torsion frequencies are varied by modifying the spanwise torsional stiffness of the blade and/or the pitch link s...

The ongoing trend towards larger wind turbines intensifies the demand for more physically realistic wind turbine rotor aerodynamics models that can predict the detailed transient pressure loadings on the rotor blades better than current engineering models. In this report the mathematical, numerical, and practical aspects of a new wind turbine rotor flow simulation code is described. This wind t...

This paper presents the development of a mixed-variable optimization framework for the aeroelastic analysis and design of active twist rotors. Proper tailoring of the blade properties can lead to the maximization of the active twist and the control authority for vibration reduction under operating conditions. Thus, using mathematical optimization, the crosssectional layout is designed using con...

this paper presents the aerodynamic design and economical evaluation of a 200 kw site specific wind turbine for the province of semnan in iran. by designing site specific wind turbines, the cost of energy which is calculated out of the annual energy production and also the cost of manufacturing the rotor are minimized. the aerodynamic design is based on the well-known blade element momentum the...