A DLM-based aerodynamic simulator for flutter is used to identify some of the most important aerodynamic drivers for the T-Tail flutter mechanism of a complete aircraft. The simulator is using the Modal Descrambling Factoring Method, which permits individual variations of each direct and each interference aerodynamic force, moment and hinge moment independently of any other force or moment. The...

Aerodynamic forces on bridges are commonly separated into static, self-excited, and buffeting force components. By delving into the relationships among force descriptors for static, self-excited, and buffeting components, novel perspectives are developed to unveil the subtle underlying complexities in modeling aerodynamic forces. Formulations for airfoil sections and those based on quasisteady ...

Recent enhancements to the development of CFD-based unsteady aerodynamic and aeroelastic reduced-order models (ROMs) are presented. These enhancements include the simultaneous application of structural modes as CFD input, static aeroelastic analysis using a ROM, and matched-point solutions using a ROM. The simultaneous application of structural modes as CFD input enables the computation of the ...

This paper examines feasibility and performance issues in using Control Moment Gyroscopes (CMGs) to control the attitude of a fixed-wing aircraft. The paper describes a control system structure that permits allocating control authority and bandwidth between a CMG system and conventional aerodynamic control surfaces to stabilize a vehicle with neutral aerodynamic stability. A simulation study ex...

Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast,...

A simple approach for computing unsteady aerodynamic forces from simulated measured strain data is proposed in this study. First, the deflection and slope of the structure are computed from the unsteady strain using the two-step approach. Velocities and accelerations of the structure are computed using the autoregressive moving average model, on-line parameter estimator, low-pass filter, and a ...

nowadays, we live in a world which quality, speed, accuracy and cost are the most important parameters in parts' design and manufacturing. due to the complexity of part manufacturing, traditional and nontraditional manufacturing techniques are used. aerodynamic tests usually requires one or several models for testing in wind tunnels and these models typically have particular complexities in whi...

wind power has been widely considered and utilized in recent years as one of the most promising renewable energy sources. in the current research study, aerodynamic analysis of the upwind three-bladed horizontal axis turbine is carried out using blade element momentum theory (bem), and a genetic algorithm (ga) is applied as an optimization method. output power generation is considered as an obj...

wind power has been widely considered and utilized in recent years as one of the most promising renewable energy sources. in the current research study, aerodynamic analysis of the upwind three-bladed horizontal axis turbine is carried out using blade element momentum theory (bem), and a genetic algorithm (ga) is applied as an optimization method. output power generation is considered as an obj...

The efficient direct optimization method is developed for aerodynamic shapes design at subsonic and supersonic flow regimes. The method combines Newton based algorithm with CFD modeling and is capable of handling large number of design variables. Aerodynamic drag is considered as the objective function minimized under volume and overall dimensions constraints. The efficiency of the method is de...