An Integral Prediction Method for Turbulent Boundary Layers Using the Turbulent Kinetic Energy Equation
An Integral Prediction Method for Turbulent Boundary Layers Using the Turbulent Kinetic Energy Equation

Author: E. A. Hirst

Publisher:

Published: 1968

Total Pages: 176

ISBN-13:

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A new integral method was devised for predicting the development of two-dimensional, incompressible, stationary turbulent boundary layers. This new method differs from the older integral methods in that it explicitly accounts for the turbulence via a characteristic turbulent velocity scale. A model of the turbulent kinetic energy integral equation is used to keep track of this turbulence scale. The model equation is developed on the basis of intuition, physical reasoning and some experimental evidence. In this new method the model equation is solved in conjunction with the momentum integral equation and the entrainment equation. A two-layer velocity profile is used. The law of the wall is assumed valid in the inner region and Coles' law of the wake is assumed valid in the outer region. The two profiles are joined by asymptotic matching; this gives an implicit equation for the skin friction. The predictions using this method are in excellent agreement with the measurements for fourteen different experimental boundary layers. (Author).

Studies of an Integral Method for Calculating Time-Dependent Turbulent Boundary Layers
Studies of an Integral Method for Calculating Time-Dependent Turbulent Boundary Layers

Author: Gary D. Kuhn

Publisher:

Published: 1973

Total Pages: 41

ISBN-13:

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An integral boundary-layer method is examined for its applicability to unsteady turbulent boundary layers. The method employs an analytical velocity profile formulation modeled after the law of the wall and the law of the wake and recently applied successfully to calculation of steady separated turbulent boundary layers. Analytical solutions developed from a small perturbation analysis indicate the method is valid for unsteady flow over a certain range of frequencies. Good comparisons were obtained between the linearized theory and results produced by a finite-difference solution of the complete nonlinear unsteady boundary-layer equations. Examination of the nature of the integral equations in the vicinity of a point of zero wall shear stress indicates that that point does not necessarily correspond to a point of separation in unsteady flow. That result is also consistent with the results of other researchers. (Author).

Analysis of Turbulent Boundary Layers
Analysis of Turbulent Boundary Layers

Author: Tuncer Cebeci

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 423

ISBN-13: 0323151051

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Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculating two-dimensional and axisymmetric laminar and turbulent boundary layers. This book will be useful to readers who have advanced knowledge in fluid mechanics, especially to engineers who study the important problems of design.

A Prediction Method for Turbulent Boundary Layers in Adverse Pressure Gradients
A Prediction Method for Turbulent Boundary Layers in Adverse Pressure Gradients

Author: W. H. Schofield

Publisher:

Published: 1981

Total Pages: 16

ISBN-13: 9780642890085

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A prediction method for turbulent boundary layers in moderate to strong adverse pressure gradients is presented. The closure hypothesis for the method is the universal velocity defect law of Schofield and Perry (1972) which restricts the method to the prediction of layers in moderate to strong adverse pressure gradient. The method is tested against nine experimentally measured boundary layers. Predictions for velocity profile shape, boundary layer thicknesses and velocity scale ratio were generally in good agreement with the experimental measurements and were superior to those given by other prediction methods. Unlike other methods the present method also gives reasonably accurate predictions for the shear stress profile of a layer. The analysis presented here is compared with previous work and helps to resolve some disagreements discerned in the literature.