A wind tunnel investigation was performed to study the flow field over a 70° swept sharped edge delta wing model at high angles of attack. The experiments were conducted in the subsonic wind tunnel at the Department of Mechanical Engineering, Sharif University of Technology. Velocity profiles have been measured using a special pitot tube and hot wire anemometer at angles of attacks of 10 to 35 ...

Abstract   Due to restrictions on the choice of relaxation time in single relaxation time (SRT) models, simulation of flows is generally limited base on this method. In this paper, the SRT lattice Boltzmann equation was used to simulate lid driven cavity flow at different Reynolds numbers (100-5000) and three aspect ratios, K=1, 1.5 and 4. The point which is vital in convergence of this scheme ...

The present work is aimed at the development of a robust, computationally efficient algorithm for the simulation of unsteady incompressible flows of interest in engineering. In particular, we focus on the extension of a fully-implicit multigr~d driven algorithm, orig/nally proposed and vaJhdated for both the two-dimensional Euler and Navier-Stokes equations in references [1,2], to three dimensi...

1 2 A general method based on adjoint formulation is discussed for the optimal control of distributed parameter systems (including boundary parameter) which is especially suitable for large dimensional control problems. Strategies for efficient and robust implementation of the method are described. A set of consistency checks are proposed for the validation of the adjoint code. The method is ap...

The study on the flow behave inside of a ball valve is important for heavy crude oil transportation. Owe to the fast progress of the numerical technique, it becomes an effective way to observe the flows inside a valve and to analyze the flow structure of the oil-water core annular flow. In the present study, the simulation of the oil-water core annular flowing through the valve is conducted...

An axi-symmetric and swirling vortex sheet is investigated as the simplest ow in which there is non-trivial vortex stretching and as a possible setting for studying vortex cancellation and singularity formation. Rayleigh's criterion indicates linear stability of a single sheet but instability for other conngurations of sheets. Due to the simplicity of vortex sheet problems, the linear modes and...

We study the Lagrangian dynamics of systems of N point vortices and passive particles in a two-dimensional, doubly periodic domain. The probability distribution function of vortex velocity, pN , has a slow-velocity Gaussian component and a significant high-velocity tail caused by close vortex pairs. In the limit for N→` , pN tends to a Gaussian. However, the form of the single-vortex velocity c...

Steady, inviscid, axisymmetric vortex ows past a sphere are obtained numerically as solutions of a partial di erential equation for the stream function. The solutions found include vortex rings, bounded vortices attached to the sphere and in nite vortex tubes. Four families of attached vortices are described: vortex wakes behind the sphere, spherically annular vortices surrounding the spherical...

In a shaken Bose-Einstein condensate, confined in a vibrating trap, there can appear different nonlinear coherent modes. Here we concentrate on two types of such coherent modes, vortex ring solitons and vortex rings. In a cylindrical trap, vortex ring solitons can be characterized as nonlinear Hermite-Laguerre modes, whose description can be done by means of optimized perturbation theory. The e...