Integrated Computational/experimental Study of Turbulence Modification and Mixing Enhancement in Swirling Jets

Integrated Computational/experimental Study of Turbulence Modification and Mixing Enhancement in Swirling Jets
Author: Jonathan Wayne Naughton
Publisher:
Total Pages: 30
Release: 2009
Genre: Eddies
ISBN:

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Swirling jet flows have been studied experimentally and computationally and the results have been compared with theory. Three-component Laser Doppler Anemometry (LDA) measurements have been carried out for swirling jets of various strengths and swirl distributions. Radial profiles of velocity have been obtained from the jet exit to 50 diameters downstream. The experimental results are consistent with previous results and with similarity theory for weakly swirling turbulent jets. However, the parametric range and spatial domain of the current data set makes it suitable for validation. Computational simulations have also been performed using a combination of Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) approaches. The results have been validated with experimental data and used to explore the mechanisms behind the increased mixing enhancement observed. The combined experimental/computational effort is still ongoing, but the experiences to date have demonstrated the effectiveness of such an approach.

An Experimental Investigation of the Effects of Swirling and Pulsing the Flow Through an Axisymmetric Duct

An Experimental Investigation of the Effects of Swirling and Pulsing the Flow Through an Axisymmetric Duct
Author:
Publisher:
Total Pages: 0
Release: 1972
Genre:
ISBN:

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It is known that the presence of swirl in a flow stream can affect heat and mass transfer rates, and pulsatile flow has important aspects in physiological studies and in non-stready turbulent flows. The investigation consisted of an experimental study of the generation and decay of swirling flow in a duct utilizing a new method of swirl generation, and the measurement of the fluctuations imposed on the steady turbulent flow profile by pulsing the flow in a duct. New results were obtained that gave insight into the effects of swirling and pulsing the flow through an asisymmetric duct.

An Experimental Investigation of the Effects of Swirling and Pulsing the Flow Through an Axisymmetric Duct

An Experimental Investigation of the Effects of Swirling and Pulsing the Flow Through an Axisymmetric Duct
Author: David Cornell Leestma
Publisher:
Total Pages: 109
Release: 1972
Genre: Aeronautics
ISBN:

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It is known that the presence of swirl in a flow stream can affect heat and mass transfer rates, and pulsatile flow has important aspects in physiological studies and in non-stready turbulent flows. The investigation consisted of an experimental study of the generation and decay of swirling flow in a duct utilizing a new method of swirl generation, and the measurement of the fluctuations imposed on the steady turbulent flow profile by pulsing the flow in a duct. New results were obtained that gave insight into the effects of swirling and pulsing the flow through an asisymmetric duct.

Experimental Investigation of Turbulent Swirling Jets

Experimental Investigation of Turbulent Swirling Jets
Author: Sara Toutiaei
Publisher:
Total Pages: 52
Release: 2014
Genre: Jets
ISBN: 9781321238839

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In this study, velocity distributions of a swirling and a non-swirling jet flows were obtained using Laser Doppler Anemometer (LDA) in the near field where both jets are at the same stages of development. The resulting mean velocity and Reynolds stress distributions and the energy budgets of the axial Reynolds stresses are assessed. All Reynolds stresses showed higher magnitude in the swirling case compared to the non-swirling one at the same measurement axial locations. The swirling jet is found to exhibit larger production, mean convection and turbulence transport terms in the energy budget of axial Reynolds stress. The result shows faster development of the swirling jet compared with the non-swirling jet and is in consistency with previous studies. The turbulent transport term is found to be responsible for the faster development of the turbulence in the swirling jet.

Turbulent Flows

Turbulent Flows
Author: G. Biswas
Publisher: CRC Press
Total Pages: 478
Release: 2002
Genre: Technology & Engineering
ISBN: 9780849310140

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This book allows readers to tackle the challenges of turbulent flow problems with confidence. It covers the fundamentals of turbulence, various modeling approaches, and experimental studies. The fundamentals section includes isotropic turbulence and anistropic turbulence, turbulent flow dynamics, free shear layers, turbulent boundary layers and plumes. The modeling section focuses on topics such as eddy viscosity models, standard K-E Models, Direct Numerical Stimulation, Large Eddy Simulation, and their applications. The measurement of turbulent fluctuations experiments in isothermal and stratified turbulent flows are explored in the experimental methods section. Special topics include modeling of near wall turbulent flows, compressible turbulent flows, and more.