Current linear aeroelastic analysis approaches are not suited for capturing the emerging concerns in bridge aerodynamics introduced by aerodynamic nonlinearities and turbulence effects. These issues may become critical for bridges with increasing spans and/or with aerodynamic characteristics sensitive to the effective angle of incidence. This paper presents a nonlinear aerodynamic force model a...

A reliable and fast method of predicting complex aerodynamic coefficients for flight simulation is presented using neural networks. The training data for the neural network is derived from numerical simulations and wind-tunnel experiments. The aerodynamic coefficients are modeled as functions of the flow characteristics and the control surfaces of the vehicle. The basic coefficients of lift, dr...

A practical three-dimensional shape optimization for aerodynamic design of a transonic wing has been performed using Evolutionary Algorithms (EAs). Because EAs coupled with aerodynamic function evaluations require enormous computational time, Numerical Wind Tunnel (NWT) located at National Aerospace Laboratory in Japan has been utilized based on the simple master-slave concept. Parallel process...

A support tower is the main structure which would support rotor, power transmission and control systems, and elevates the rotating blades above the earth boundary layer. A successful design should ensure safe, efficient and economic design for the whole wind turbine system. It should provide easy construction and easy access for maintenance of the rotor components and sub-components. UHPC mater...

Current design load estimation procedures for wind turbines often do not accurately treat the statistical nature of loads. Current practice for wind turbine load analysis is reviewed. The authors’ opinions on the shortcomings of these practices are discussed. Experience gained from current research on statistical load extrapolation methods is reviewed. Statistical modeling techniques are presen...

Passive torque servo system (PTSS) simulates aerodynamic load and exerts the load on actuation system, but PTSS endures position coupling disturbance from active motion of actuation system, and this inherent disturbance is called extra torque. The most important issue for PTSS controller design is how to eliminate the influence of extra torque. Using backstepping technique, adaptive fuzzy torqu...

This paper is concerned with bump-less transfer of parametrized disturbance observer 1 based controller (DOBC) with Individual Pitch Control (IPC) strategy for full load operation of wind 2 turbine. Aerodynamic cyclic loads are reduced by tuning multivariable DOBC with the objective 3 to reduce output power fluctuation, tower oscillation and drive-train torsion. Furthermore tower 4 shadow and w...

The effect of boundary layer oscillating suction (BLOS) on the vortex structure high-load linear compressor cascades is studied by a high-fidelity numerical calculation. oscillation parameters (amplitude and frequency) control (suction position mass flow) are continuously adjusted. It was found that higher aerodynamic efficiency could be obtained with suitable parameters. This achieved because ...

Aerodynamic forces due to blade-tip clearance eccentricity are a known destabilizing source in rotating machinery with unshrouded impellers. Dynamic also appear shrouded impellers, changes the pressure gap between impeller casing and its shroud. These load-dependent typically characterized by cross-coupled stiffness coefficient (k > 0). This paper reviews archival literature for quantificati...