Two-dimensional, Incompressible, Turbulent Curved-wall Jets

Two-dimensional, Incompressible, Turbulent Curved-wall Jets
Author: George Mon
Publisher:
Total Pages: 60
Release: 1973
Genre: Jets
ISBN:

NDS TO ATTACH ITSELF AND FLOW ALONG THE SURFACE. A theoretical and experimental study of the effects of the surface curvature on the flow field of a two-dimensional, incompressible, turbulent jet has been made. By using a perturbation technique, the governing equations for the flow have been obtained and solved numerically. There is flow similarity for a curved-wall jet when m = 1, and for the flow of a plane wall jet when the curvature approaches infinity. Two spiral and three circular cylindrical surfaces were tested. The mean velocity profiles and static pressure distributions were measured at various stations for each surface. In addition, the point of separation was found for Reynolds numbers, based on the nozzle width, in the range of 500 to 4000. The growth rates of the jet width and the rate of decay of the maximum velocity were deduced from the velocity measurements. (Modified author abstract).

Turbulent Flows

Turbulent Flows
Author: Jean Piquet
Publisher: Springer Science & Business Media
Total Pages: 767
Release: 2013-04-17
Genre: Technology & Engineering
ISBN: 3662035596

obtained are still severely limited to low Reynolds numbers (about only one decade better than direct numerical simulations), and the interpretation of such calculations for complex, curved geometries is still unclear. It is evident that a lot of work (and a very significant increase in available computing power) is required before such methods can be adopted in daily's engineering practice. I hope to l"Cport on all these topics in a near future. The book is divided into six chapters, each· chapter in subchapters, sections and subsections. The first part is introduced by Chapter 1 which summarizes the equations of fluid mechanies, it is developed in C~apters 2 to 4 devoted to the construction of turbulence models. What has been called "engineering methods" is considered in Chapter 2 where the Reynolds averaged equations al"C established and the closure problem studied (§1-3). A first detailed study of homogeneous turbulent flows follows (§4). It includes a review of available experimental data and their modeling. The eddy viscosity concept is analyzed in §5 with the l"Csulting ~alar-transport equation models such as the famous K-e model. Reynolds stl"Css models (Chapter 4) require a preliminary consideration of two-point turbulence concepts which are developed in Chapter 3 devoted to homogeneous turbulence. We review the two-point moments of velocity fields and their spectral transforms (§ 1), their general dynamics (§2) with the particular case of homogeneous, isotropie turbulence (§3) whel"C the so-called Kolmogorov's assumptions are discussed at length.

Engineering Turbulence Modelling and Experiments 6

Engineering Turbulence Modelling and Experiments 6
Author: Wolfgang Rodi
Publisher: Elsevier
Total Pages: 1011
Release: 2005-05-05
Genre: Science
ISBN: 0080530958

Proceedings of the world renowned ERCOFTAC (International Symposium on Engineering Turbulence Modelling and Measurements). The proceedings include papers dealing with the following areas of turbulence: · Eddy-viscosity and second-order RANS models · Direct and large-eddy simulations and deductions for conventional modelling · Measurement and visualization techniques, experimental studies · Turbulence control · Transition and effects of curvature, rotation and buoyancy on turbulence · Aero-acoustics · Heat and mass transfer and chemically reacting flows · Compressible flows, shock phenomena · Two-phase flows · Applications in aerospace engineering, turbomachinery and reciprocating engines, industrial aerodynamics and wind engineering, and selected chemical engineering problems Turbulence remains one of the key issues in tackling engineering flow problems. These problems are solved more and more by CFD analysis, the reliability of which depends strongly on the performance of the turbulence models employed. Successful simulation of turbulence requires the understanding of the complex physical phenomena involved and suitable models for describing the turbulent momentum, heat and mass transfer. For the understanding of turbulence phenomena, experiments are indispensable, but they are equally important for providing data for the development and testing of turbulence models and hence for CFD software validation. As in other fields of Science, in the rapidly developing discipline of turbulence, swift progress can be achieved only by keeping up to date with recent advances all over the world and by exchanging ideas with colleagues active in related fields.

Report

Report
Author: United States. National Bureau of Standards
Publisher:
Total Pages: 696
Release: 1968
Genre: Hydraulic engineering
ISBN:

Turbulence Measurements in the Wall Jet Layer of Impinging Round Jet

Turbulence Measurements in the Wall Jet Layer of Impinging Round Jet
Author: Serdar Malak
Publisher:
Total Pages: 86
Release: 2012
Genre: Acoustical engineering
ISBN:

The objective of this thesis is to understand how turbulence affects the impinging jet flow and heat transfer mechanism under acoustic actuaion. This work is based upon the experimental work including velocity and turbulence measurements in various cases and is a continuation of studies of Necati Bilgin and Orcun Kor . Acoustic actuation is provided by a loudspeaker controlled by a function generator. Acoustic waves generated by the loudspeaker reaches nozzle and formed periodic fluctuations in flow. Strouhal number, which is dimensionless reperentation of actuation frequeny, is varied in the range of 0