Two-dimensional unsteady wake characteristics and Strouhal number discontinuity have been investigated numerically in flow past rectangular cylinder of different aspect ratio using lattice Boltzmann method. Effect (AR) has studied for Reynolds (Re) the range from 75 to 150. For investigation between 0.05 1 considered. Different regimes, such as two-rows regime, modulated fully developed regime ...

Direct numerical simulation data of a 24 compression ramp configuration are used to analyze the shock motion. The characteristic frequencies in the incoming boundary layer are reported for reference. The shock wave motion exhibits high-frequency spanwise wrinkling, as well as low-frequency streamwise motion. Correlations between the incoming flow and the shock motions, as well as the downstream...

The goal of this work is to develop low order dynamical systems models for the unsteady aerodynamic forces on small wings and to better understand the physical characteristics of unsteady laminar separation. Reduced order models for a fixed, high angle of attack flat plate are obtained through Galerkin projection of the governing Navier-Stokes equations onto POD modes. Projected models are comp...

Results for time-dependent, viscous, incompressible flows were investigated using the lattice-Boltzmann (BGK) automata. The decay of a synthetic turbulent flow field and the time evolution of an initial vortex were simulated for validation purposes. The focal point was the investigation of the instationary flow around a square obstacle in a twodimensional channel for a range of Reynolds numbers...

In this paper, the implicitly implemented LES method and fifth order bandwidth-optimized WENO scheme are used to make comprehensive studies on the interaction of vortex rings and shock waves of the MVG controlled flow at M=2.5 and Re θ θ θ θ =5760. The kinetic information of the vortex rings is carefully studied and provided. The interaction of the streamwise vortices and vortex rings are inves...

Trapping of vortices in a cavity has been explored in recent years as a drag reduction measure for thick airfoils. If, however, trapping fails, then oscillation of the cavity flow may couple with elastic vibration modes of the airfoil. To examine this scenario, the effect of small amplitude vertical motion on the oscillation of the shear layer above the cavity is studied by acoustic forcing sim...

Two-dimensional numerical simulations are used to examine the vorticity flux and slot entrance effects in zero-net mass-flux devices. The simulations allow us to extract a simple scaling law for the vorticity flux which provides insight into the relative importance of the various operational parameters. In addition to this, a semi-analytical model is proposed in order to determine the pressure ...

This paper describes the non-linear dynamics of premixed flames responding to harmonic velocity disturbances. It extends a prior computational study which determined the key parameters influencing the nonlinear flame characteristics. It was shown that the linear and nonlinear characteristics of the flame dynamics were controlled by the superposition of two sources of flame disturbances: those o...