Currently the lifespan of rotor blades is determined based on a conservative lifetime calculation. This leads to blades being discarded while they still possess a significant residual amount of flight-hours. Blade health monitoring systems are desired to actively track the strains in the blade thereby drastically extending the technical life expectancy. A major drawback is in the need for an el...

In this paper we obtain a limit model for a turbine blade fixed to a 3D solid. This model is a three-dimensional linear elasticity problem in the 3D part of the piece (the rotor) and a two-dimensional problem (the nonlinear shallow shell equations) in the 2D part (the turbine blade), with junction conditions in the part of the turbine blade fixed to the rotor. To obtain this model, we perform a...

Introduction Rotor blade lllJunes are uncommon in the Armed Forces because of continual safety training and protection in relation to the use of helicopters. Rarely, accidents do still happen as a reminder that even with acute awareness of ground movements, incidents will occur. A review of the total United States Army rotor blade accidents between 1972 and 1991 reported 24 strike injuries, 12 ...

A single rotor CFD model using wall-modeled Large Eddy Simulations (LES) was performed to predict the unsteady loading on the blade surface under partial admission. Geometry of the rotor blade of high pressure steam turbine of a 500 MW fossil-fuel power plant was used for this study. Periodically changing inlet boundary model was developed for single rotor model to simplify a full annular of th...

The Active Vibration and Noise Reduction (AVINOR) aeroelastic simulation code for helicopter rotor blades is described. AVINOR is a research code that has been developed at UCLA and the University of Michigan for the purpose of conducting computationally efficient aeroelastic response analyses while maintaining a level of fidelity so as to be suitable for preliminary design of helicopter rotor ...

in the present paper, the aeroelastic stability of helicopter rotor blade is determined using aeroelastic frequency response function. the aeroelastic model of blade is obtained by combining dowell - hodges beam model with loewy unsteady aerodynamic theory which considers an unsteady wake beneath the rotor. equations are formed and aeroelastic frequency response functions are obtained by invert...

More cost-effective wind turbines with higher rated power, are desired to emerge in the near future. The current trend in wind energy is for this reason the increase of the wind turbine dimensions. Increasing their size is however strongly limited by the rotor blades structural integrity towards occurring aeroelastic loads, especially with respect to blade fatigue. Advanced (re)active load redu...

An aeroelastic model of a smart rotor system (which incorporates blade-mounted trailing-edge flap actuators and conventional root pitch actuation) is presented in linear time invariant state space form. The servo-flap deflections are modeled as producing incremental lift and moment variations, so that any linear aerodynamic actuator can be evaluated. This smart rotor model is used to conduct pa...