Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Series Paper
Author: Experimental Investigation of Turbulent Oscillatory Boundary Layers
Author: Experimental Investigation of Turbulent Oscillatory Boundary Layers
Author: Bjørn Lykke JensenPublisher:
ISBN:
Category : Boundary layer
Languages : da
Pages : 157
Book Description
Preliminary Experimental Investigation of Effect of Free-stream Turbulence on Turbulent Boundary-layer Growth
Author: S. J. KlinePublisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 70
Book Description
An Experimental Investigation of Turbulent Boundary Layers Along Curved Surfaces
Author: Ronald M. C. SoPublisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 276
Book Description
Experimental Investigation of Turbulent Boundary Layer with Uniform Blowing at Moderate and High Reynolds Numbers
Author: Gazi HasanuzzamanPublisher: Cuvillier
ISBN: 9783736975583
Category :
Languages : en
Pages : 180
Book Description
Experimental investigation in turbulent boundary layer flows represents one of the canonical geometries of wall bounded shear flows. Utmost relevance of such experiments, however, is applied in the engineering applications in aerospace and marine industries. In particular, continuous effort is being imparted to explore the underlying physics of the flow in order to develop models for numerical tools and to achieve flow control. Flow control experiments have been widely investigated since 1930's. Several flow control technique has been explored and have shown potential benefit. But the choice of control technique depends largely on the boundary condition and the type of application. Hence, friction drag of subsonic transport aircraft is intended to be reduced within the scope of this Ph. D. topic. Therefore, application of active control method such as microblowing effect in the incompressible, zero pressure gradient turbulent boundary layer was investigated. A series of experiments have been performed in two different wind tunnel facilities. Wind tunnel from Department of Aerodynamics and Fluid Mechanics (LAS) was used for the measurements for moderate Reynolds number range in co-operation with the wind tunnel from Laboratoire de M ́ecanique de Feiret Lille for large Reynolds number range. Measurements are conducted with the help of state-of-the-art techniques such as Laser Doppler Anemometry, Particle Image Velocimetry and electronic pressure sensors.
Experimental and Theoretical Study of Turbulent Oscillatory Boundary Layers
Author: Jing Yuan (Ph. D.)Publisher:
ISBN:
Category :
Languages : en
Pages : 244
Book Description
Sediment transport is of crucial importance to engineering projects in coastal regions, so it is of primary interest in coastal engineering. The driving forces for sediment transport are mostly determined by the hydrodynamics of oscillatory turbulent bottom boundary layers, which is still not well understood. Therefore, the goal of this thesis is to improve the present experimental and theoretical understandings on this subject. A high-quality experimental study including a large number of tests which correspond to full-scale coastal boundary layer flows is performed using a state-of-the-art oscillating water tunnel (OWT) for flow generations and a Particle Image Velocimetry system for velocity measurements. The experimental results suggest that the logarithmic profile can accurately represent the boundary layer flows in the very near-bottom region, so the log-profile fitting analysis can give highly accurate determinations of the hydrodynamic roughness, the theoretical bottom location and the bottom shear stress. The current velocity profiles in the presence of sinusoidal waves indicate a two-log-profile structure suggested by the widely-used Grant-Madsen model. However, for weak currents in the presence of nonlinear waves, the two-log-profile structure is contaminated or even totally obliterated by the boundary layer streaming which is related with the temporal variation of the turbulent eddy viscosity. This, together with some other experimental evidence, motivates the development of a new theoretical model which adopts a rigorous way to account for a time-varying turbulent eddy viscosity. The model accurately predicts the mean and leading Fourier components of the velocity and the bottom shear stress for various flow conditions. Most importantly, the boundary layer streaming related to the time-varying turbulent eddy viscosity is reasonably predicted, which leads to successful predictions of the mean velocity embedded in nonlinear-wave tests and the current velocity profiles in the presence of either sinusoidal or nonlinear waves. The predictions reveal significant differences between boundary layer flows in OWTs and in the coastal environment, which must be considered when interpreting OWT results for sediment transport.
An Experimental Investigation of Pressure Driven Three-dimensional Turbulent Boundary Layers
Author: Stanford University. Thermosciences DivisionPublisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 390
Book Description
An Experimental Investigation Towards the Active Control of Turbulent Boundary Layers
Author: Stuart Alan JacobsonPublisher:
ISBN:
Category :
Languages : en
Pages : 524
Book Description
An Experimental Investigation of a Three-dimensional Turbulent Boundary Layer
Author: Donald Ralph ZimmermanPublisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 348
Book Description