Minimizing the aerodynamic drag and the lift of the train coach remains a key issue for high-speed trains. With the development of computing technology and computational fluid dynamics (CFD) in the engineering field, CFD has been successfully applied to the design process of high-speed trains. However, developing a new streamlined shape for high-speed trains with excellent aerodynamic performan...

wing to the material differences in the natural and engineered systems, the design of a biological-inspired aircraft possesses considerable challenges to the aircraft designer. The birds employ a structure of hollow bones, flexible joints and muscles, and feathers to morph their wings to suit the desired flight condition. While the aircrafts use the rigid joints and structures to sustain the ae...

Aerodynamic testing of low-rise structures is fraught with difficulties that can be the cause of large measurement errors, resulting in the underestimation of aerodynamic pressures by a factor of as much as two. The errors are primarily attributable to the inadequate knowledge and simulation of wind flows affecting low-rise buildings, especially residential homes in suburban environments. A typ...

Birds usually moult their feathers in a particular sequence which may incur aerodynamic, physiological and behavioural implications. Among birds, hummingbirds are unique species in their sustained hovering flight. Because hummingbirds frequently hover-feed, they must maintain sufficiently high flight capacities even when moulting their flight feathers. A hummingbird wing consists of 10 primary ...

The development of micro aerial vehicles has been hindered by a poor understanding of the flight dynamics associated with the unique aerodynamic regime. This study experimentally estimates the aerodynamic damping derivatives of flat-plate wings with aspect ratios less than 3 at a Reynolds number of 7.5 × 104; when combined with previously published results detailing the lateral and longitudinal...

Shape control of adaptive wings has the potential to enhance wing aerodynamic performance during cruise and high-speed off-design conditions. A possible way to attain this objective is to develop specific technologies for trailing edge morphing, aimed at variating the airfoil camber. In the framework of SARISTU project (EU-FP7), an innovative structural system incorporating a gapless deformable...

A numerical investigation of the dynamic Fluid Structure Interaction (FSI) of a yacht sail plan submitted to harmonic pitching is presented to address both issues of aerodynamic unsteadiness and structural deformation. The FSI model — Vortex Lattice Method fluid model and Finite Element structure model — has been validated with full-scale measurements. It is shown that the dynamic behaviour of ...

The recent development of large wind turbines poses new challenges with regard to understanding the mechanisms surrounding unsteady flow-structure interaction. The larger and more flexible blades imply risks from an aeroelastic point of view and urge the need to properly understand and model these phenomena. Due to limited experimental data available in this field, Computational Fluid dynamics ...

At the most fundamental level, main rotor loading noise is caused by the harmonically-varying aerodynamic loads (acoustic pressures) exerted by the rotating blades on the air. Rotorcraft main rotor noise is therefore, in principle, a function of rotor control inputs, and thus the forces and moments required to achieve steady, or “trim”, flight equilibrium. In certain flight conditions, the ensu...

As aircraft wings become much more flexible due to the use of light-weight composites material, adverse aerodynamics at off-design performance can result from changes in wing shapes due to aeroelastic deflections. Increased drag, hence increased fuel burn, is a potential consequence. Without means for aeroelastic compensation, the benefit of weight reduction from the use of light-weight materia...