Experimental and numerical studies of the Rayleigh-Taylor instability for bounded liquid films with injection through the boundary

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dc.contributor.author Abdelall, Fahd Fathi en_US
dc.date.accessioned 2005-03-03T21:51:49Z
dc.date.available 2005-03-03T21:51:49Z
dc.date.issued 2004-04-07 en_US
dc.identifier.uri http://hdl.handle.net/1853/5153
dc.description.abstract One of the most demanding engineering issues in Inertial Fusion Energy (IFE) reactors is the design of a reaction chamber that can withstand the intense photons, neutrons and charged particles due to the fusion event. Rapid pulsed deposition of energy within thin surface layers of the fusion reactor components such as the first wall may cause severe surface erosion due to ablation. One particularly innovative concept for the protection of IFE reactor cavity first walls from the direct energy deposition associated with soft X-rays and target debris is the thin liquid film protection scheme. In this concept, a thin film of molten liquid lead is fed through a silicon carbide first wall to protect it from the incident irradiations. Numerous studies have been reported in the literature on the thermal response of the liquid film to the intermittent photon and ion irradiations, as well as on the fluid dynamics and stability of liquid films on vertical and upward-facing inclined surfaces. However, no investigation has heretofore been reported on the stability of thin liquid films on downward-facing solid surfaces with liquid injection through (i.e. normal to the surface of) the bounding wall. This flow models the injection of molten liquid lead over the upper end cap of the reactor chamber. The hydrodynamics of this flow can be interpreted as a variation of the Rayleigh-Taylor instability due to the effect of the bounding wall which is continuously fed with the heavier fluid. In order to gain additional insight into the thin liquid film protection scheme, experiments have been conducted to investigate the critical issues associated with this concept. To this end, an experimental test facility has been designed and constructed to simulate the hydrodynamics of thin liquid films injected normal to the surface of and through downward-facing flat walls. In this doctoral thesis, the effect of different design parameters (film thickness, liquid injection velocity, liquid properties and inclination angle) on liquid film stability has been examined. The results address the morphology of the film free surface, the frequency of droplet formation and detachment, the size and penetration depth of the detached droplets, and the interface wave number. These experimental data have been used to validate a novel mechanistic numerical code based on a level contour reconstruction front tracking method over a wide range of parameters. The results of this investigation will allow designers of IFE power plants to identify appropriate windows for successful operation of the thin liquid film protection concept for different coolants. en_US
dc.format.extent 4187474 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.publisher Georgia Institute of Technology en_US
dc.subject Experimental methods en_US
dc.subject Inertial and magnetic fusion energy
dc.subject Thermo-fluids
dc.subject Rayleigh-Taylor
dc.subject Liquid films
dc.subject Numerical front tracking method
dc.subject.lcsh Liquid films Stability en_US
dc.subject.lcsh Thin films Stability en_US
dc.subject.lcsh Nuclear fusion en_US
dc.subject.lcsh Fusion reactor walls Materials en_US
dc.title Experimental and numerical studies of the Rayleigh-Taylor instability for bounded liquid films with injection through the boundary en_US
dc.type Dissertation en_US
dc.description.degree Ph.D. en_US
dc.contributor.department Mechanical Engineering en_US
dc.description.advisor Committee Chair: Abdel-Khalik, Said en_US


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