A lightweight flapping-wing micro air vehicle (MAV) was designed and built and successfully filed in the sky. The unsteady aerodynamics associated with this MAV was detailedly studied by using the method of computational fluid dynamics (CFD).The variations of different parameters of the flapping MAV, such as flapping amplitude, pitch amplitude and flapping frequency, were investigated with nume...

The strength design of the high-speed maglev train lacks specific methods, and analysis mainly refers to standards traditional wheel-rail technology, which cannot meet requirements development. An efficient structure evaluation method for trains is proposed based on Shanghai system. combined operation conditions are first constructed by linear superposition combination single conditions. Throug...

This letter presents a data-driven optimal control policy for micro flapping wing unmanned aerial vehicle. First, set of trajectories are computed off-line based on geometric formulation dynamics that captures the nonlinear coupling between large angle motion and quasi-steady aerodynamics. Then, it is transformed into feedback system according to framework imitation learning. In particular, an ...

This paper proposes a nonlinear H∞ controller for stabilization of velocities, attitudes and angular rates of a fixed-wing unmanned aerial vehicle (UAV) in a windy environment. The suggested controller aims to achieve a steady-state flight condition in the presence of wind gusts such that the host UAV can be maneuvered to avoid collision with other UAVs during cruise flight with safety guarante...

An investigation into the total blockage effects on aerodynamic drag in closed-wall wind tunnel testing has been carried out by computational fluid dynamics (CFD). The simulation of flow past two different realistic, full-scale, heavy-duty truck models was conducted. The models were placed at different yawing angles in the virtual wind tunnels with blockage ratio of about 10%; which is exactly ...

The aerodynamics of future hypersonic air-breathing vehicles will be greatly affected by high-enthalpy or “real gas” effects. It is the purpose of a recent NATO Research and Technology Organization study to assess the readiness of computational fluid dynamics to simulate high-enthalpy flows. This paper summarizes the results of this effort through the discussion of four test cases: a transverse...

Force measurements from experiments conducted in water on a flapping-and-pitching thin flat plate wing of semi-elliptic planform at low Reynolds numbers are reported. Time varying force data, measured using a force transducer, provide a means to understand the mechanisms that lead to enhanced performance observed in insect flight compared to fixed wing aerodynamics. Experimental uncertainties a...

Continued studies have been undertaken to investigate and develop aerodynamic models that predict aircraft response in nonlinear unsteady flight regimes for transport configurations. The models retain conventional static and dynamic terms but replace conventional acceleration terms with indicial functions. In the Subsonic Fixed Wing Project of the NASA Fundamental Aeronautics Program and the In...