No description available.

No description available.

No description available.

A series of experiments has been conducted for comparison with the results of a computer code called CHYMES. It is intended to calculate the coarse mixing of molten metal with water by solving the equations of the Separated Flow Model. These are derived by volume averaging and the terms that relate them to the particular case of participate flow are discussed. An experimental apparatus that is compatible with CHYMES and coarse mixing has been constructed which projects a jet of ball bearings into a thin tank of water. Experiments over a wide range of conditions were conducted at room temperature. Owing to practical difficulties only one, poorly controlled experiment with hot ball bearings was performed. Under nearly all sets of conditions an arrow-shaped plume was obtained. The speed of penetration of the plume varied little with changes in experimental conditions. The width of the plume was most strongly influenced by the widths of the tank and the jet. The individual paths of some particles were followed; it appeared that their motion was mostly dependent on their position in the plume. A model of the plume is proposed, based upon its front being impermeable to water in the vertical direction. Much of the detail of the experimental plumes was not present in the computational results and they responded differently to changes in conditions. It is proposed that this is a result of the different forms of the two sets of plumes. To rectify this an experimental plume was volume averaged. A method to determine a suitable averaging volume size is described. The process results in a plume similar to the computational ones. The length scales required for volume averaging to be successful are discussed and the possibility that this method is inappropriate for describing coarse mixing is admitted.

The subject of the thesis is concerned with the study of the turbulent spreading and the gravity spreading processes in surface jets and surface plumes influenced by the cross-flow. A total of five different discharge and cross-flow configurations were under investigation. They are, namely, (i) submerged jets in unconfined cross-flow, (ii) surface jets in deep and shallow cross-flows, (iii) surface plumes in deep cross-flow, (iv) full-depth jets in cross-flow and (v) full-depth plumes in cross-flow, reported in Chapters IV, V, VI, VII and VIII respectively. / The effect of the gravity stratification, the effect of the free water surface and the confined effect of the channel bottom on the spreading of the turbulent flows have been determined from control experiments. The experimental data have been correlated in a unified manner, using suitable scales and dimensionless parameters. They are also related to a general integral formulation, established for this type of problems. / The results of an extensive series of previous experimental investigations, of related problems of jets and plumes in cross-flow have been reanalysed and they are integrated into the various parts of the thesis to complement and confirm the present investigation. / On the whole, the thesis has succeeded in providing a general description of the turbulent spreading and the gravity spreading processes in flows of different discharge and cross-flow configurations.

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?

No description available.

No description available.

Inspired by the need to study injectant flow patterns near the test surface, a supersonic free-jet facility was designed and constructed. This facility provides a Mach 1.95 flow over a test section area of 6.35 cm by 5.08 cm. The facility was thoroughly tested and proved that it is durable, versatile, and capable of providing repeatable test conditions. When compared to the main supersonic tunnel at VPI & SU, the free-jet facility has many advantages, including greater optical and spatial access, longer available test durations, and less time needed between tests for the storage tanks to be refilled. As a part of the project, several diagnostic techniques were evaluated in the facility. Normal, sonic injection of helium through a circular injector was studied as a way to evaluate nanoshadowgraph photography, oil flow photography, and infrared imaging as qualitative flow visualization methods. Quantitative measurements of the local helium concentration within the boundary layer were taken to evaluate the effectiveness of an existing hot-film concentration probe. The tests showed that oil flow visualization is a very effective technique in the free-jet facility, producing clear photographs that could be directly scaled. Nanoshadowgraph photography also produced clear photographs of the flow field, although this method was more difficult to implement in the free-jet facility than in the main supersonic tunnel. Finally, infrared imaging, which was not possible in the main supersonic tunnel without major hardware reconfigurations, showed great promise as a method for studying normal injection. Although the tests revealed no conclusive information about injectant flow patterns in the boundary layer, a heat transfer analysis showed that it may be possible in future studies to use this technique as a way to quantitatively measure local helium concentration at the surface. Helium concentration was measured for test cases with both air and helium injection. The measurements were taken at two axial locations with the probe positioned at a distance of 0.1 injector diameters above the test surface. The air injection tests showed helium concentration levels up to 30 percent mole fraction, which is erroneous since no helium was present in the flow. Based on these results it was concluded that the existing probe was ineffective in the free-jet facility, with an uncertainty level of no less than 25 percent mole fraction helium. The cause of the high uncertainty and overall ineffectiveness was most likely the probe calibration and data reduction methods. / Master of Science

Liquid and slurry jets were injected through a circular orifice transverse to a M = 3.0 airflow. Mass samples of both jets were taken across the plume 30 injector diameters downstream. Pitot and static pressure surveys were taken across the liquid jet. These data allowed the calculation of distributions across the liquid jet plume of Mach number, air mass flow, liquid-to-air ratio, and momentum flux. A correlation for the liquid concentration in the downstream plane is also presented. In the plume, there is a core region of subsonic airflow carrying two-thirds of the mass collected in the plume. In the core, the liquid mass flow is nearly constant from side-to-side at a given height, and the average velocity of the liquid is only 30 to 60% of the local air velocity. A supersonic mixing region covering two-thirds of the area of the plume surrounds the core region. Comparison with the results from this direct sampling data indicate that correlations developed from photographic techniques are inadequate in determining the jet penetration and width of liquid and slurry jets. The slurry jet showed substantial phase separation. A 30% mass-loaded slurry of 1-5 µm silicon dioxide particles mixed with water was injected, and the local loading varied from a low of 13% at the bottom of the plume to 100% outside the liquid plume. The local loading increased as the jet boundary was approached from any direction. / Master of Science