Significant progress has been made towards understanding the large scale features of wall-bounded shear flow in zero pressure gradient (ZPG) turbulent boundary layers (TBL). Here we consider their effects in adverse pressure gradient (APG) flows where the pressure gradient parameter is held constant and Reynolds number is varied. This is done by documenting the changes in the mean velocity, str...

This study describes the turbulent processes in the upper ocean boundary layer forced by a constant surface stress in the absence of the Coriolis force using large-eddy simulation. The boundary layer that develops has a two-layer structure, a well-mixed layer above a stratified shear layer. The depth of the mixed layer is approximately constant, whereas the depth of the shear layer increases wi...

This article describes a 3D CFD (computational fluid dynamics) simulation implementation of the stepped planning hull in calm water. The turbulent free surface flow around the stepped planing hull is computed with a RANSE method, using the solver ANSYS-CFX. The turbulence model used is standard k–ε. In order to simulate the disturbed free surface, VOF model is implemented. The CFD model has bee...

\Flutter of a buckled plate as an example of chaotic motion of a deterministic autonomous system," 22 References 1. Ludwig, G. R., \An experimental investigation of the sound generated by thin steel panels excited by turbulent ow (boundary layer noise)," U. 21 be found. The formulation given by Eq. (63) represents a new way of estimating the radiated acoustic pressure from an elastic plate exci...

Turbulent Prandtl number distributions are measured in a laboratory boundary layer flow with bed roughness, active blowing and sucking, and scalar injection near the bed. The distributions are significantly larger than unity, even at large distances from the wall, in apparent conflict with the Reynolds analogy. An analytical model is developed for the turbulent Prandtl number, formulated as the...

This contribution deals with a self-consistent description of time-mean turbulent lubricant flow, i.e. flow through a wedge-shaped gap confined by counter-sliding solid surfaces. The methods adopted are matched asymptotic expansions, where the slenderness or aspect ratio of the gap and the accordingly defined Reynolds number represent the perturbation parameters. As a remarkable result, a load-...

A square splittered and unsplittered rod is placed in a turbulent boundary layer developed over a flat plate. The effect of the resulting disturbances on the local heat transfer coefficient is then studied. In both cases the square rod modifies the flow structure inside the boundary layer. As a result, a stagnation point, a jet and wake area are generated around the square rod, each making a co...

The present work is carried out to investigate heat transfer and friction factor characteristics of fluid (air) flow through turbulent channel i.e. parallel plate heat exchanger for different geometry and designs parameters, with a bottom plate applied to uniform constant heat flux thermal boundary condition, and upper plate is provided with a insulated condition. The fluid domain is designed u...

Birds and gliders exploit warm, rising atmospheric currents (thermals) to reach heights comparable to low-lying clouds with a reduced expenditure of energy. This strategy of flight (thermal soaring) is frequently used by migratory birds. Soaring provides a remarkable instance of complex decision making in biology and requires a long-term strategy to effectively use the ascending thermals. Furth...

We present the development, validation, and application of a numerical model for the simulation of bottom boundary layer (BL) flows induced by arbitrary finite amplitude waves. Our approach is based on coupling a ‘near-field’ local Navier–Stokes (NS) model with a ‘far-field’ inviscid flow model, which simulates large scale incident wave propagation and transformations over a complex ocean botto...