La thèse porte sur l'étude d'un système de contrôle de la pression au sein de réservoirs d’ergols cryogéniques (dihydrogène ou dioxygène) dans le cadre de missions spatiales de longue durée. Ce système de contrôle doit permettre d’éviter la perte excessive d’ergols associée à un contrôle basique de la pression consistant en l’évacuation directe d’une fraction du fluide. Le système alternatif étudié, dit de contrôle thermodynamique, repose sur la réinjection d’un spray sous-refroidi permettant d’abaisser température et pression dans un réservoir soumis à une chauffe (en pratique, le rayonnement solaire). Nous avons analysé les performances de ce système en développant en parallèle un banc d'essai adapté aux conditions du laboratoire, et un modèle théorique de type 0D, à base de bilans globaux, de l’effet du spray sous-refroidi sur les caractéristiques thermodynamiques de l’enceinte. La confrontation des mesures et des calculs a permis de valider l’outil de modélisation théorique. Les caractéristiques du système réel (ensemble des circuits d'injection et de refroidissement) ont ensuite été introduites dans le modèle théorique afin de quantifier de façon réaliste les gains offerts par le système de contrôle thermodynamique, i.e. en prenant en compte la pénalité en masse associée à ces circuits. Des solutions optimales de contrôle de la pression au sein de réservoirs d’ergols cryogéniques lors de missions spatiales de longue durée ont pu alors être proposées. / This PHD thesis deals with the study of a pressure control system inside a cryogenic propellant tank for long duration space missions. This system must be able to reduce propellant losses induced by direct venting, which is the simplest pressure control system. The alternative system which has been studied, called Thermodynamic Vent System (TVS), is based on reinjecting subcooled spray to make the pressure and temperature decrease in a heated tank. The system performance has been analysed developing simultaneously an experimental setup, adapted to laboratory environment, and a theoretical 0D-modelling of subcooled spray impact on tank's thermodynamic characteristics. Facing experimental and theoretical results has permitted to validate the 0D-modelling tool. Inputing the real system characteristics in theoretical modelling has enabled to assess the effective gains of thermodynamic vent system. Finally, optimal solutions to control pressure inside a cryogenic propellant tank for long duration space missions have been proposed.

The master’s thesis deals with the question of petrol engine boosting by rotary turbochargers. The objective of the thesis is to project suitable turbocharger for defined single-cylinder petrol engine. After selecting the suitable turbocharger type it will follow the construction of the computational model of the single-cylinder turbocharged petrol engine in the Lotus Engine Simulation software. In the computational model is boost pressure regulated by the turbine waste gate valve. The result will be the boost pressure values scheme for the highest possible torque so that the maximum combustion pressures will not exceed the value of 9,5 MPa. There are summarized findings and results in the conclusion of the thesis.

The proposed work is dealing with control design of pump-tank system as part of broader water-supply network with using of mechatronic approach. The main goal of this work is design of control for regulation of flow, pressure and water level in tank in water-supply network of Vsetin city. This water-supply network consists of various components, such as pumps, pipes, valves, tanks etc. For the purpose of the control design is necessary to create a model of pipe network. The solution of hydraulic analysis is obtained by using the gradient method, which was implemented into the software solution named ADAM. The results of hydraulic analysis are compared with measured values of flow and pressure and difference of these values has to be minimalized by proposed calibration and verification process. The calibration and verification process was implemented in software ADAM. The essence of design control is formulating control problem as optimization problem. Therefore the output of higher control layer is set of procedural rules, which determines for example speed of pumps in time etc. Results were verified by using for this purpose developed computational server (ADAM Server).

No / Advances in micromoulding technology are now allowing mass production of complex, three-dimensional functional products having sub-milligram masses and carefully tailored surface finishes. In order to create a viable manufacturing process for these components, accurate process monitoring and product evaluation are essential in order to highlight process problems and production of substandard parts. The present study describes work implementing a suite of sensors on a commercial micromoulding machine for detailed process interrogation. Evaluation of demoulded products is performed with a single camera based system combined with custom software to allow for three-dimensional characterisation of products during the process.

A masters thesis deals with the question of deisel engine boosting by rotary turbochargers. The objective of the thesis is to propose suitable turbocharger´s concept for defined diesel combustion engine with power of 430 [kW]. The air boosting pressure is controlled by exhaust gas flow through the turbine and different EGR regimes, which are considered in the basic and corrected calculations. The final turbocharger´s concept is proposed to satisfy the defined technical requirements. Next technical recommendations are briefly summarized in the thesis conclusion for following turbocharger´s concept application.