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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Direct and large-eddy simulations of three-dimensional jets using the lattice Boltzmann method

Soo, Jin Hou 12 1900 (has links)
No description available.
2

Mixing and combustion in precessing jet flows / by Gregory John Robert Newbold.

Newbold, Gregory, 1969- January 1998 (has links)
Bibliography: leaves 173-183. / xviii, 183 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Demonstrates that the local strain rate in the fluidic precessing jet (FPJ) flames is reduced by an order of magnitude relative to momentum dominated simple jet flames and this difference is shown to correlate with reduced NOx emissions and increased emissivity. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 1998
3

The effect of grindability upon nozzle pulverization

Graham, Robert W., Ragone, Stanley, Reed, Joseph C. January 1948 (has links)
To determine the effect of the grindability of coal upon nozzle pulverization by running tests, in a small nozzle pulverizer unit, on various grindability coals from different coal seams in Virginia and West Virginia. The authors want the reader to know that maximum pulverization was not the object of this test. The relative pulverization of the different coals was the goal to be obtained. In a more efficiently designed nozzle pulverizer unit with a better nozzle, higher pressure drop across the nozzle, and different coal-air ratios, greater coal pulverization can be obtained. 1. A small nozzle pulverizer unit can be built on which reproducible results may be obtained. 2. From the results obtained, grindability has an effect upon nozzle pulverization, but it is small over the range of Hardgrove Grindabilities studied. 3. The Hardgrove Grindability seemed to have less effect upon the per cent of fines produced than on the larger sized coal particles. / M.S.
4

Dense gas effects in a converging-diverging nozzle

Fry, Richard N. 23 December 2009 (has links)
Analytical and computational models for the solution of steady inviscid flows in a converging-diverging nozzle are presented for a general fluid. The main emphasis is placed on Bethe-Zel'dovich-Thompson fluids, i.e., those having specific heats so large that the fundamental derivative of gasdynamic is negative over a finite range of pressures and temperatures. Three general classes of flow are delineated which include two nonclassical types in addition to the usual classical flows; the latter are qualitatively similar to those of a perfect gas. The nonclassical flows are characterized by isentropes containing as many as three sonic points. Numerical solutions depicting finite strength expansion shocks, steady flows with shock waves standing upstream of the nozzle throat, and steady flows containing as many as three shock waves are presented. Nonclassical flows having arbitrarily large exit Mach numbers can be obtained only if a sonic expansion shock is formed in the nozzle. / Master of Science
5

Structures and turbulence characteristics in a precessing jet flow / by Gerald Manfred Schneider.

Schneider, Gerald Manfred January 1996 (has links)
Bibliography: leaves 228-262. / xxvi, 262, [xxvii] leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on a fundamental investigation of a precessing jet flow which is analogous to that which emanates from the fluidic nozzle. A 'mechanical nozzle' is used to generate a well-defined PJ flow. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 1997?
6

Optimisation of solid rocket motor blast tube and nozzle assemblies using computational fluid dynamics

Scholtz, Kelly Burchell January 2017 (has links)
Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017. / A framework for optimising a tactical solid rocket motor nozzle is established and investigated within the ANSYS Workbench environment. Simulated results are validated against thrust measurements from the static bench firing of a full-scale rocket. Grid independence is checked and achieved using inflation based meshing. A rocket nozzle contour is parametrized using multiple control points along a spline contour. The design of experiments table is populated by a central composite design method and the resulting response surfaces are used to find a thrust optimised rocket nozzle geometry. CFD results are based on Favre-mass averaged Navier-Stokes equations with turbulence closure implemented with the Menter SST model. Two optimisation algorithms (Shifted Hammersley Sampling and Nonlinear Programming by Quadratic Lagrangian) are used to establish viable candidates for maximum thrust. Comparisons are made with a circular arc, Rao parabolic approximation and conical nozzle geometries including the CFD simulation there-off. The effect of nozzle length on thrust is simulated and optimised within the framework. Results generally show increased thrust as well as demonstrating the framework's potential for further investigations into nozzle geometry optimisation and off-design point characterisation.
7

Effect of inlet configurations on the aerodynamics of swirl combustors

Guruswamy, Jayaram January 1983 (has links)
The flowfield in a swirling combustor with a Confinement Ratio of 1.6 was simulated in water. Qualitative measurements were made from flow visualization in a horizontal water rig with the help of Pliolite beads and liquid dye. Velocity and turbulence measurements were made in a cold air flow rig. Mean velocity measurements were made using a five hole Pitot probe and turbulence measurements were obtained from a hot wire anemometer. All the flow visualization tests were made with Reynold's number between 10,000 and 47,500, and quantitative measurements in the cold air flow were made at a Reynold's number of 7.1x10<sup>5</sup>. The experiment was conducted for two configurations of the combustor system inlet- 1) Straight inlet and 2) S-inlet. Both configurations were tested with swirling and non-swirling flows. The straight inlet configuration with non-swirling flow produced a uniform corner recirculation near the wall of the combustion chamber. The S-inlet made the corner recirculation zones unequal. The introduction of swirling in the flow created a central recirculation zone in addition to the corner recirculation zone. It was found that the central recirculation zone was most prominent in the configuration with the S-inlet and swirling flow. An oscillating central core was seen in the straight inlet case. The average turbulence level was higher in the configuration with the s-inlet. / M. S.
8

The effects of secondary flows on the heat transfer to turbine nozzle endwall and rotor shroud.

Nebo, Anthony Chibuzo January 1979 (has links)
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographical references. / Sc.D.
9

Navier/Stokes/Direct simulation Monte Carlo modeling of small cold gas thruster nozzle and plume flows

Nanson, Richard A. January 2002 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: CFD; computational fluid dynamics; plume; nozzle; DSMC; numerical modelling. Includes bibliographical references (p. 83-86).
10

A Monte-Carlo-based simulation of jet exhaust nozzle thermal radiative signatures

Chapman, David D. 06 October 2009 (has links)
An important consideration in the design of military aircraft is observability, or how visible an aircraft is to hostile weapons. One area of great importance to overall observability is an aircraft’s infrared signature, particularly the infrared emissions from the exhaust nozzle and plume. This creates the need for accurate modeling of the infrared signatures from these sources as a design aid or for comparison of candidate designs. To that end, a parametric model has been developed based on the General Electric F110-GE-129 jet engine. The basis of the model is a highly flexible Monte-Carlo ray-trace formulation which is capable of simulating real surface behavior, such as specular reflections, and allows for variation of input parameters such as temperature, surface properties, and geometry. For given input parameters, the model predicts the overall infrared signature due to surface radiation from the exhaust nozzle and interior components. It also indicates the relative contribution of each interior surface to the overall signature and predicts the image that would be seen using infrared imaging equipment. The basic principles of the simulation method and the theory behind the application are discussed. Results are presented, primarily in graphical format, and recommendations are made for further work. / Master of Science

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