Thesis (Ph. D.)--University of Wisconsin--Madison, 1965. / Typescript. Vita. Abstracted in Dissertation abstracts, v. 25 (1965) no. 10, p. 5829. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 169-174).

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1911. / The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed February 27, 2009)

M.Ing. (Electrical And Electronic Engineering) / The theme of this thesis is the time compression of energy in electrical systems with the aim of improving the efficiency and average power throughput capability of existing pulse compression systems. Recent success in the design of pulse lasers indicated successful operation at repetition rates of up to 2kHz, demanding more powerful pulse power supplies. These pulse lasers require unusually high peak power, not obtainable with conventional switching techniques. Typical pulse voltages of up to 40kV with peak currents of lOkA and rise times of 150ns are required. Traditionally thyratrons have been used for this application, but the limited lifetime of these devices is a major shortcoming, especially when operating at 2kHz. New switching techniques were needed. Excellent results have been obtained using saturable inductors as magnetic switches in pulse compressors, but notwithout limitations. The generation of heat due to core losses tends to limit the power throughput capability of these compressors, especially in the final stages. The minimisation of these losses is therefore of utmost importance. In order to improve the current systems, a study of the basic principles of compression was conducted. Loss-mechanisms, especially in the magnetic components, were modelled with the object of minimising losses. The limitations imposed on the system by flux conservation in magnetic and dielectric materials, led to the development of the new concept of bipolar compression. A full-scale bipolar compressor and pulse power supply was constructed and experimental results on this system are presented, showing an improvement in the efficiency. A new method for designing pulse compressors, incorporating core losses,evolved from this development

Compressor blades often have a small 'spike' in the surface pressure distribution at the leading edge. This may result from blade erosion, manufacture defects or compromises made in the original design process. In this thesis it is shown that these spikes will increase the loss generated by a blade only when they become large enough to initiate boundary layer transition at the leading edge through a separation bubble; this process increases profile loss by about 30%. A criterion is presented, based on the spike diffusion, which can be used to determine whether leading edge transition will occur or not; this criterion is simple and quick to determine and has to potential to be used on a production line to reject those leading edges that would otherwise be detrimental. The spikes are also shown to have a significant effect on the flow close to the endwalls. If they cause leading edge transition in this region then they will cause a growth in the size of the three-dimensional separations that exist in the corner between the blades' suction surfaces and the endwalls. On the low speed stator tested this process increased hub loss by around 100%. Thus to prevent spikes becoming large a new method for producing a 'spikeless' leading edge has been developed; this leading edge can be attached easily to the thickness distribution of any blade and was found to be sharp, that is with very high curvature at the leading edge point. This spikeless leading edge was also found to be the best when the effects of real manufacture deviations, measured off of a production line, were considered. Asymmetry was found to be detrimental and bluntness was only beneficial when unrealistically large deviations were considered. The best leading edge geometry is therefore sharp and symmetric.

No description available.

M.Tech. (Mechanical and Industrial Engineering) / Please refer to full text to view abstract

No description available.

No description available.

No description available.

Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished