Asymptotic closure model for inertial particle transport in turbulent boundary layers

Instabilities in turbulent boundary layers

An investigation of a model of turbulence generation in the wall region of a turbulent boundary layer is made through direct numerical simulations. The model is based on the instability of a streak. First, a laminar boundary layer disturbed by a continuous blowing through a slot is simulated in order to reproduce and further investigate the results reported from the experiments of Acarlar & Smi...

Transitional-turbulent spots and turbulent-turbulent spots in boundary layers.

Two observations drawn from a thoroughly validated direct numerical simulation of the canonical spatially developing, zero-pressure gradient, smooth, flat-plate boundary layer are presented here. The first is that, for bypass transition in the narrow sense defined herein, we found that the transitional-turbulent spot inception mechanism is analogous to the secondary instability of boundary-laye...

Control of turbulent boundary layers

The objective of this paper is to give an overview of recent progress on boundary layer control made by the author’s research group at University of California, Los Angeles. A primary theme is to highlight the importance of a certain linear mechanism and its contribution to skin-friction drag in turbulent boundary layers—and the implication that significant drag reduction can be achieved by alt...

Assessment of inflow boundary conditions for compressible turbulent boundary layers

A description of different inflow methodologies for turbulent boundary layers, including validity and limitations, is presented. We show that the use of genuine periodic boundary conditions, in which no alteration of the governing equations is made, results in growing mean flow and decaying turbulence. Premises under which the usage is valid are presented and explained, and comparisons with the...

Towards a Closure Scheme for Turbulent Boundary Layers Using the Attached Eddy Hypothesis