L'application de l'injection fluidique dans le divergent d’une tuyère axisymétrique supersonique pour dévier le vecteur poussée est une alternative attrayante aux systèmes classiques, puisqu’elle peut se substituer aux dispositifs mécaniques. Un tel concept de vectorisation est actuellement en cours d'application sur de récents avions de combat équipés de tuyères planes. La vectorisation fluidique peut trouver également son application dans les systèmes de contrôle d’altitude de satellites ; ce principe peut réduire le nombre de tuyères habituellement utilisées. L’un des objectifs principaux de ce travail consiste à analyser et étudier les différents phénomènes mis en jeu lors de l'injection d'un fluide secondaire dans le divergent de la tuyère. Partant de cette étude, un modèle analytique, basé sur le calcul d'un bilan complet de tous les efforts exercés sur les parois de la tuyère a été construit. Ce modèle permet de donner une estimation rapide de la déviation du vecteur-poussée. L'influence de certains paramètres sur cette déviation a été également abordée. Des calculs numériques ont été réalisés par la suite afin de valider ce modèle. Les résultats obtenus par notre modèle ont été par ailleurs comparés avec les données expérimentales disponibles dans la littérature. / Fluid injection application in the divergent of a supersonic axisymmetrical nozzle is an attractive way to produce vectored thrust since it can remove the need for complex mechanical devices. Such concept of thrust vectoring is currently applied for some recent jet-fighters with planar nozzles. However, fluidic thrust-vectoring may be interesting for satellite attitude control system; thrust-vectoring may reduce the number of nozzles usually used. One of the aims of this work is to analyse and study the numerous parameters concerned by the fluid secondary injection in the divergent nozzle. From this study, an analytical model, based on calculation of all efforts applied on the nozzle walls, is constructed. This model makes it possible to give a fast estimation of the thrust-vectoring. The effect of many parameters on the thrust vectoring was also studied. Extensive numerical calculations have been carried out thereafter to validate this model. The results obtained by our model were also compared to some existing experimental data which give a significant confidence of the model.

In this thesis, various kinds of theory to account for injection locking and pulling in the literature are studied and compared. On this basis, this thesis derives a generalized locking equation when injection signal is modulated signal. In applications, a novel RF sensing circuit for cognitive radio system is proposed using injection locking and frequency demodulation. Detailed circuit architecture and sensing principle are also described in the thesis. In implementation, a hybrid VCO and a CMOS VCO have been separately used with the other components to establish the RF sensing circuit. The simulation relies on a discrete-time numerical method. Comparison between measurement and simulation shows very good agreement. This RF sensing circuit can simultaneously sense frequency and power with a sensing speed up to 400 MHz/ms and a sensing sensitivity as low as -80 dBm, showing that the presented prototype can fast and reliably sense frequency and power for analog and digital modulation signals.

A 3D 8-component thermal compositional simulation study has been performed to evaluate the merits of steam-propane injection and a novel vertical-smart horizontal well system for the Lombardi reservoir in the San Ardo field, California. The novel well system consists of a vertical steam injector and a horizontal producer, whose horizontal section is fully open initially, and after steam breakthrough, only one-third (heel-end) is kept open. A 16x16x20 Cartesian model was used that represented a quarter of a typical 10acre 9-spot inverted steamflood pattern in the field. The prediction cases studied assume prior natural depletion to reservoir pressure of about 415 psia. Main results of the simulation study may be summarized as follows. First, under steam injection, oil recovery is significantly higher with the novel vertical-smart horizontal well system (45.5-58.7% OOIP at 150-300 BPDCWE) compared to the vertical well system (33.6-32.2% OOIP at 150-300 BPDCWE). Second, oil recovery increases with steam injection rate in the vertical-smart horizontal well system but appears to reach a maximum at about 150 BPDCWE in the vertical well system (due to severe bypassing of oil). Third, under steam-propane injection, oil recovery for the vertical-smart horizontal well system increases to 46.1% OOIP at 150 BPDCWE but decreases to 51.6% OOIP at 300 PDCWE due to earlier steam breakthrough that resulted in reduced sweep efficiency. Fourth, for the vertical well system, steam-propane injection results in an increase of oil recovery to 35.4-32.6% OOIP at 150-300 BPDCWE. Fifth, with steam-propane injection, for both well systems, oil production acceleration increases with lower injection rates. Sixth, the second oil production peak in the vertical-smart horizontal well system is accelerated by 24-50% in time for 150-300 BPDCWE compared to that with pure steam injection.

This thesis is composed of three parts. In the first part, various kinds of theory to account for injection locking and pulling in the available literature are studied and compared. In the second part, this thesis proposes an experimental setup with self-made hybrid VCO and commercially available equipments and components to measure the characteristics of injection locking and pulling. This thesis also performs simulation to verify the measured results. The simulation mainly relies on the circuit envelope technique that has been developed in our laboratory. Comparison between measurement and simulation shows good agreement in the injection-locking characteristic curves and the injection-pulling spectrum characteristics. In the third part, this thesis carries out an RFIC design for a fractional-N frequency synthesizer with special features on quantization-noise cancellation and PLL nonlinearity reduction using TSMC 0.13£gm CMOS process.

Thesis (MTech (Mechanical Engineering))--Peninsula Technikon, 2003. / Word processed copy. Summary in English. Includes bibliographical references (leaves 60-63). Also available online.

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 218-244). Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [101]-106).

Thesis (Ph.D.(Chemistry))--University of Pretoria, 1994. / Abstract in English. Includes bibliographical references.

This thesis deals with the optimization of the production technology of the cap tube made by injection molding. Series production is set at 5 000 000 units per year; the minimum time of the production is 5 years. A literary study is developed, focusing on the technology of injection molding in molds including the possibilities of the optimization of the production by changing the structure of the mold. The practical part of the thesis is devoted to the optimization of existing mold with cold runner system for the production of the cap tube, using the hot runner system supplied by Synventive. The change of the structure of the mold involves changing the three plate mold to a two plate mold. It is about changing the fixed part of the mold in which the hot runner system is placed; it is composed of standards parts of the company HASCO. Based on the technological parameters the injection machine Krauss Maffei KM 80-380 CX is chosen. There is a technical-economical evaluation of the optimization of the production by using the hot runner system at the end of the thesis.

No description available.