We study numerically the two-dimensional flow past a circular cylinder as a prototypical transitional flow, and investigate the influence of a generic slip boundary condition on the wake dynamics. We show that slip significantly delays the onset of recirculation and shedding in the wake behind the cylinder. As expected, the drag on the cylinder decreases with slip, with an increased drag sensit...

Unsteady drag, unsteady lift, and movement of one or two moving particles caused by the passage a planar shock wave are investigated using particle-resolved simulations viscous flows. The particle motion analysis is carried out based on for under Mach number 1.22 Reynolds 49, migration fluid forces investigated. behavior different densities configurations. time evolution drag lift changed inter...

The motion and the action of microbubbles in homogeneous and isotropic turbulence are investigated through ~three-dimensional! direct numerical simulations of the Navier–Stokes equations and applying the Lagrangian approach to track the bubble trajectories. The forces acting on the bubbles are added mass, drag, lift, and gravity. The bubbles are found to accumulate in vortices, preferably on th...

The motion of the ball thrown by a pitcher is influenced by three forces: gravity, drag force due to air resistance, and lift force which deflects a ball vertically or laterally due to ball spin. The lift force acting on the ball increases with spin rate and movement speed when the spin axis of the ball is orthogonal to the direction of ball movement. Among individual pitchers there were great ...

High performance force sensors often encounter the conflicting requirements of fine sensitivity and wide bandwidth. While there is an intrinsic tradeoff between these two metrics that cannot be physically avoided for any force transducer, through proper optimization the product of these two can be maximized. Similarly, the requirements of multiple sensing axes and overall compactness are also o...

The flow field around a flat plate of infinite span has been investigated for several values of the angle of attack. Numerical predictions have been compared to experimental measurements, in order to examine the effect of turbulence model and grid resolution on the resultant aerodynamic forces acting on the plate. Also the influence of the free-stream turbulence intensity, at the entrance of th...

We discuss a new numerical scheme involving adaptive boundary conditions which allows to compute, at very low Reynolds numbers, drag and lift of airfoils with rough surfaces efficiently with great precision. As an example we present the numerical implementation for an airfoil consisting of a line segment. The solution of the NavierStokes equations is singular at the leading and the trailing edg...

Maritime Platforms Division within DSTO is currently studying the science and technology of autonomous underwater vehicles for defence applications. Part of this work involves a study of the hydrodynamics and manoeuvrability of these vehicles and the development of methods to determine the hydrodynamic coefficients of submerged bodies as a function of their shape. This report describes the appl...

We combine three-dimensional descriptions of the movement patterns of the shoulder, elbow, carpus, third metacarpophalangeal joint and wingtip with a constant-circulation estimation of aerodynamic force to model the wing mechanics of the grey-headed flying fox (Pteropus poliocephalus) in level flight. Once rigorously validated, this computer model can be used to study diverse aspects of flight....

In this project fluid flow over various airplane wings was simulated using lattice gas cellular automata (LGCA)[1]. The aim of this simulation was to study how the drag and lift forces on a wing vary for various wing shapes, wing pitches and wind speed. The results of this study are presented, along with key details of the LGCA implementation that was used to construct the wind tunnel and inter...