We present work towards a parameter-free method for turbulent flow simulation based on adaptive finite element approximation of the Navier-Stokes equations at high Reynolds numbers. In this model, viscous dissipation is assumed to be dominated by turbulent dissipation proportional to the residual of the equations, and skin friction at solid walls is assumed to be negligible compared to inertial...

In this paper, known probabilistic methods for estimating the thickness of boundary layer a two-dimensional laminar flow viscous incompressible fluid are extended to three-dimensional flows compressible medium. Their applicability problems boundary-layer stability is studied with LOTRAN3 software package, which allows us compute position laminar-turbulent transition in aerodynamic configurations.

Wall-bounded turbulent shear flows are perhaps the last area in ‘classical’ incompressible turbulence in which there still are open questions about basic physical mechanisms. There are two competing conceptual models. In the first one, wall turbulence is just a modification of ordinary shear turbulence occuring when the latter is a near wall, and is therefore dependent on the prior existence of...

The rate of viscous energy dissipation in a shear layer of incompressible Newtonian fluid with injection and suction is studied by means of exact solutions, nonlinear and linearized stability theory, and rigorous upper bounds. The injection and suction rates are maintained constant and equal and this leads to solutions with constant throughput. For strong enough suction, expressed in terms of t...

The rate of viscous energy dissipation in a shear layer of incompressible Newtonian fluid with injection and suction is studied by means of exact solutions, nonlinear and linearized stability theory, and rigorous upper bounds. For large enough values of the injection angle a steady laminar flow is nonlinearly stable for all Reynolds numbers, while for small but nonzero angles the laminar flow i...

A turbulent flow is characterised by an unpredictable behaviour, a broad spectrum of length and time scales, and its strong mixing properties. Turbulent flows have a great mixing potential involving a wide range of vortical length scales. In steady flows, the turbulence measurements must be conducted at high frequency to resolve the small eddies and the viscous dissipation process. They must al...

We propose an invariant feature space for the detection of viscous dominated and turbulent regions (i.e., boundary layers wakes). The developed methodology uses principal invariants strain rotational rate tensors as input to unsupervised Machine Learning Gaussian mixture model. selected is independent coordinate frame used generate processed data, it relies on rate, which are Galilean invariant...

Abstract

the current study presents the results of the aerodynamic noise prediction of the flow field around a naca 0012 airfoil at a chord-based reynolds number of 100,000 and at 8.4 degree angle of attack. an incompressible large eddy simulation (les) turbulence model is applied to obtain the instantaneous turbulent flow field. the noise prediction is performed by the ffowcs williams and hawkings (fw-...

We consider the problem of magnetic-energy amplification by a turbulent flow of conducting fluid. This effect is known as the small-scale turbulent dynamo, and it is believed to be relevant in application to magnetic fields in astrophysical objects. It is, in fact, a generic property of random (in time and/or space) flows that they can amplify magnetic fluctuations at scales smaller than the sc...