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 ...

An unsteady aerodynamics model of a flexible unmanned air vehicle is presented in this paper. The unsteady aerodynamics results from structural vibrations of the flexible airframe which affect the airflow around it. The doublet lattice method, which is a potential flow based panel method, is used for obtaining the basic unsteady aerodynamics model. It gives the pressure distribution on a liftin...

The creation of an integrated rotorcraft conceptual and preliminary design framework at DLR involved the development of geometry and fuselage aerodynamics modules at the Institute of Aerodynamics and Flow Technology. After a short revision of the RIDE rotorcraft design environment architecture this paper focuses on the implementation of these disciplinary modules. The aim of the geometry module...

The present research investigates the torsional aeroelasticity of the blade of an H-type vertical axis wind turbine subject to stall and post-stall conditions in various Reynolds regimes, which is experienced by the blade in a full revolution. In order to simulate the aerodynamics, a new model based on a combination of the Double Multi Streamtubes (DMST) model and the nonlinear multi-criteria C...

The aerodynamics of micro air vehicles (operating at the chord Reynolds number of 10 5 or below) is substantially influenced by the unsteadiness of the wind gust and the aircraft’s light weight. In this effort, we investigate the active flow control of the dielectric barrier discharge actuator for flows around the SD7003 airfoil, with the chord Reynolds number of 6×10 4 , to enhance our underst...

The basis of this work was to understand the generation of lift and thrust of a flapping biwing ornithopter, which is influenced by its geometrical, dynamic, kinematic and aerodynamic features by following a generic approach in order to identify and mimic the mechanisms. As further development of earlier work, three-dimensional rigid thin wing is considered in flapping and pitching motion using...

The exploitation of computational fluid dynamics for non linear aeroelastic simulations is mainly based on time domain simulations of the Euler and NavierStokes equations coupled with structural models. Current industrial practice relies heavily on linear methods which can lead to conservative design and flight envelope restrictions. The significant aeroelastic effects caused by nonlinear aerod...

Unlike a transonic flow in compressible aerodynamics, a ship cruising steadily in a channel at nearly the linearized long wave speed generates unsteady wave motion. In a channel of limited width, solitons are radiated periodically up-stream. Such waves may have been the cause of a fatal accident at the Port of Harwich, England, and were described by a witness “like the white cliffs of Dover”. A...

Analysis of the aerodynamic forces acting on baseball pitches from major league games reveals a large variance in the measured coefficients of lift and drag. We have examined possible explanations for this effect and found that, while uncertainties introduced by measurement error and the method of reporting major league pitch trajectories do explain some of the spread, the reasons for the large...