The kinematics and hydrodynamics of free-swimming mayfly larvae (Chloeon dipterum) were investigated with the aid of a simple wake visualisation technique (tracer dyes) and drag measurements on dead insects. The basic swimming movement consists of a high-amplitude dorso-ventral undulation and, during continuous swimming, this produces a wake of ring vortices shed alternately to the dorsal and v...

In this paper an energy harvesting system based on a piezoelectric converter to extract energy from airflow and use it to power battery-less sensors is presented. The converter is embedded as a part of a flexure beam that is put into vibrations by von Karman vortices detached from a bluff body placed upstream. The vortex street has been investigated by Computational Fluid Dynamics (CFD) simulat...

We use direct Lyapunov exponents to identify Lagrangian coherent structures (LCSs) in a bioinspired fluid flow: the wakes of rigid pitching panels with a trapezoidal planform geometry chosen to model idealized fish caudal fins. When compared with commonly used Eulerian criteria, the Lagrangian method has previously exhibited the ability to define structure boundaries without relying on a presel...

In this study, the aerodynamic sound generated from the inclined circular cylinder was investigated experimentally and numerically. The generated sound and a coherent length of velocity fluctuation along the cylinder axis were measured by a low-noise wind tunnel with endplates. The sound and the flow in wake were also simulated by Large Eddy Simulation and Lighthill-Curle’s equation. We got the...

We perform numerical expe riments wit h a novel cellularautomaton fluid mod el. T he mod el has simple pair -in t eraction rules and works in arb it rarily man y dimensions; here we consider the twodimension al case . By observing the smoothing-out of the velocity profile of a shear flow and t he relax ati on of a shea r wave, we measure t he kin em ati c shear viscosity and obtain a value of R...

In this study the centre manifold is applied for reduction and limit cycle calculation of a highly nonlinear structural aeroelastic wing. The limit cycle is arisen from structural nonlinearity due to the large deflection of the wing. Results obtained by different orders of centre manifolds are compared with those obtained by time marching method (fourth-order Runge-Kutta method). These comparis...