The origin of strong magnetic fields in the Universe can be explained by amplifying weak seed fields via turbulent motions on small spatial scales and subsequently transporting the magnetic energy to larger scales. This process is known as the turbulent dynamo and depends on the properties of turbulence, i.e., on the hydrodynamical Reynolds number and the compressibility of the gas, and on the ...

In this study, temporally-evolving incompressible and compressible Turbulent Shear Layer (TSL) instability problem is solved using an all-speed (allMach), implicit, non-dissipative and kinetic energy conserving algorithm. An in-house, fully parallel, finite-volume Direct Numerical Simulation (DNS) solver was developed using PETSc. Convergence characteristics at low-Mach numbers were also improv...

Background Turbulent blood flow is a cause of energy loss in the cardiovascular system, and can thus be seen as a measure of flow inefficiency. Novel 4D flow CMR methods permit estimation of intracardiac turbulent kinetic energy (TKE). On the basis of the Reynolds number, one might expect that larger left ventricular (LV) size would promote higher TKE values, and thus lower flow efficiency. In ...

We present new observations from a microstructure-equipped ocean glider in the southeastern Beaufort Sea of the Canadian Arctic. The glider measured 345 quasi-vertical profiles of microstructure shear and finescale temperature and salinity. We use these measurements to calculate the rate of dissipation of turbulent kinetic energy and to assess the strength of turbulent mixing. The region is cha...

The present paper is primarily concerned with modeling complex turbulent wall-bounded flow in spray-painting processes by using a commercial CFD code. Computational results of turbulent channel flow with low Reynolds numbers are compared with DNS data in order to obtain the performance of turbulence models and near wall treatments. The realizable k-ε model with the nonequilibrium wall function ...

Compressibility may strongly reduce the redistribution of turbulent kinetic energy. The question of how such effects can be taken into account in turbulence models is addressed here. First, a corresponding stochastic turbulence model is developed on the basis of a simplification of the generalized Langevin model for turbulent velocities. This model is then reduced to a deterministic model that ...

Direct numerical simulations were performed to investigate the physics of a spatially-developing turbulent boundary layer flow subjected to spanwise oscillating electromagnetic force. The electromagnetic force beneath the flat plate was locally given with a finite length. A fully implicit fractional step method was employed to simulate the flow. The mean flow properties and the Reynolds stresse...

This paper pRisents nwneric:a.l analysis of the incompressible turbulent flow field in a single cavity of the stepped multi-cavity seal. The dimensionless bulk pressure drop for the cavity with and without groove has been investigated for four different Reynolds numbers and three different shaft ro~ating speeds. SIMPLER algoritlun is applied to solve the NavierStokes equation and lowReynolds nu...

energy equation for turbulent flow in a rotating system was derived in terms of second order correlation tensors, where the correlation tensors were functions of space coordinates, distance between two points and time. to reveal the relationship of turbulent energy between two points, one point was taken as origin of the coordinate system. due to rotation, the coriolis force played an important...

A numerical study is performed to investigate nonlinear processes during internal wave generation by the oscillation of a background barotropic tide over a sloping bottom. The focus is on the near-critical case where the slope angle is equal to the natural internal wave propagation angle and, consequently, there is a resonant wave response that leads to an intense boundary flow. The resonant wa...