Slush is a two phase flow of solid particles (crystals) and liquid at the triple point temperature, and constitutes an appealing alternative to liquid propellants for space launchers. The crystals give to the mixture higher density and lower specific enthalpy than liquid, enabling reduced tank volume storage and larger fuel holding time. However, the presence of solid crystals significantly modifies the thermo-hydraulics of the fuel transport, and requires novel predictive tools and diagnostic techniques for efficiently exploiting slush propellants. This thesis contributes to both aspects. In particular, this work studied the flow pressure losses and the heat transfer of solid-liquid mixtures in pipelines, combining experimental and numerical methods. Hydraulic and thermal flow features were analyzed separately with substitute mixtures chosen to mimic the behavior of slush flows in engine fuel feed systems. A dedicated facility was designed and built. The pipeline mounted conventional probes for pressure, temperature and mass flow rate measurements. Moreover, a capacitance-based density meter was developed and validated to measure the mixture's solid content. Optical flow visualization and image processing routines were combined to retrieve particulate phase distribution and velocity fields. The experimental work was complemented with 3D Unsteady Reynolds Averaged Navier Stokes simulations in OpenFOAM. The simulations coupled the Euler-Euler approach with the granular kinetic theory for the treatment of the solid dispersed phase. The model was validated with the experimental results on the pressure drop, heat transfer and solid volume fraction.The resulting physical insights and the proposed empirical correlations on the pressure drop and heat transfer in solid-liquid flows contribute to move a step forward towards slush propelled space launchers. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

The Diploma thesis describes the implementation of innovative production of protective liner to the manufacturing company. The liner is manufactured in sizes of nominal diameter DN 200 - DN 500. The material is low-alloy steel EN 10216-2 10CrMo9-10. For the production innovation, the technology of pipe end flaring by a movable mandrel was chosen. Verification of the functionality of this technology was performed using analytical calculations and numerical simulation of FEM. The results of numerical methods were compared with the results of a practical experiment. The experiment was performed on 5 test specimens with a diameter of 273 mm. The machine device was a hydraulic press with a nominal force of 2000 kN and equipped with pressure and position sensors. The experimentally obtained values of force and the tool path dependence were similar with the values of FEM simulation. The difference in the value of the force in the maximum tool path was 290 kN. The flared diameter was formed to a value of 319 mm. This value corresponds to 16.5% of increased nominal diameter, which is sufficient from design point of view. Non-destructive tests ruled out the presence of crack defects on the flared diameter. According the new set up working procedure was produced the first real part. Significant financial savings of CZK 3.5 - 5.3 million / year were quantified in the technical and economic evaluation. Return on necessary investments is between the 9th - 14th manufactured pieces (approx. 15% of the annual production volume). In conclusion, innovation has promising results and will be issued by the company into the production process.

Diploma thesis makes a summary of today’s state of CIPP methods designed for sewer relining. Thesis presents classification of CIPP methods between other NO-DIG technologies. Then CIPP methods are divided into groups according to the material used for the liner, applied resin, installation method and curing method. Designing of the CIPP liner used for sewer renovation is also part of this diploma thesis. The result of the theoretical part of this work is a table, which states suitability of particular methods for use in a sewer of specific technical properties. Practical part of bachelor’s thesis is dealing with the analysis of defects of an existing sewer in the city Přerov. Analysis was done due to the camera examination provided by the company Wombat s.r.o. Later the table developed in theoretical part was applied, and then the suitability of use of all parameters of CIPP liners was commented. At the end the plan of works is designed, with the plan for pumping of water included.

Diploma thesis is focused on analisis of the steam generator tube bundle on the basis calculation by the finite elements method and softwaru ANSYS. Next it will also také account of job descriptions and methods of operation of the equipment propřed plan revision kontrol points that will be most critical. Annexes included documentary of model from the SolidWorks.

This thesis describes the workplace workshop in ALPS Electric in Sebranice. It contains a brief description of machinery and theory of technological projecting. For this department is created proposal of the modification flow racks and the transportation. There are budgets for this proposals. The aim of the thesis is to create drawings documentation for the current and future location the workplace workshop.

For the qualification and validation of two-phase CFD-models for medium and large-scale industrial applications dedicated experiments providing data with high temporal and spatial resolution are required. Fluid dynamic parameter like gas volume fraction, bubble size distribution, velocity or turbulent kinetic energy should be measured locally. Considering the fact, that the used measurement techniques should not affect the flow characteristics, radiation based tomographic methods are the favourite candidate for such measurements. Here the recently developed ultrafast X-ray tomography, is applied to measure the local and temporal gas volume fraction distribution in a vertical pipe. To obtain the required frame rate a rotating X-ray source by a massless electron beam and a static detector ring are used. Experiments on a vertical pipe are well suited for development and validation of closure models for two-phase flows. While vertical pipe flows are axially symmetrically, the boundary conditions are well defined. The evolution of the flow along the pipe can be investigated as well. This report documents the experiments done for co-current upwards and downwards air-water and steam-water flows as well as for counter-current air-water flows. The details of the setup, measuring technique and data evaluation are given. The report also includes a discussion on selected results obtained and on uncertainties.

The interest of how small non-spherical particles transport behaviour when transported in pipe-flow is of large interest in a variety applications. This kind of theory have been used when studying composite manufacturing and how particles behaves in the human lungs. The main focus is to study the statistical deposition rate in a flow-field with and without capillary action and gravity. Two kind of particle shapes are of main interest which are prolate and oblate spheroids. In this study the method of vector projection is used to track particle orientation instead of the more common methods of Euler-angles or quaternions. The method of tracking the particle motion used is Lagrangian tracking method which solves the equations of motion for the particles individually. When studying particles of nano-scale the importance of the phenomenon called Brownian motion arises. The inclusion if the Brownian motion gives rise to the solving of stochastic differential equations for the particle transport. To solve the resulting equations of transport a MATLAB program was developed to using the numerical Euler-Maruyama scheme. Simulations is done with a large amount of particles with a varying particle size and aspect ratio. The deposition results are compared between the different particles shape and sizes. It is seen that the effect of the Brownian motion on particle deposition rate increases with a smaller particle size. It is also concluded that the Brownian motion is the dominating reason for particle deposition. From comparing particle shape and size it is seen to have a major effect of the particles deposition. Including capillary action or gravity the inclusion doesn't affect particles deposition as much.

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Today waste management has entered a new stage. Since wastes still contain natural materials and energy that can be extracted, it should be treated in effective ways, for example, for energy recovery or material recycling. Many countries and the municipalities have therefore made waste treatment strategies in accordance with for example, EU directives or governmental regulations. In such circumstances, Envac is one of waste management companies in Sweden, which collects different kinds of waste fractions through an underground pipe system by means of air pressure. In Hammarby sjöstad in Stockholm, currently organic waste, combustible waste, and newspapers are collected by the Envac’s system, however a cross contamination between organic fraction and newspapers has been observed. We therefore performed on-site waste transporting experiments in order to solve this cross contamination and suggest an optimum transporting condition which means that waste bags can be transported with high rate and acceptable condition to the terminal. From the previous study, bag quality and transporting speed were supposed to be the factors that affect the waste purity. Then on-site experiments were designed and carried out based on these factors. In the end, we proposed the optimum condition depending on the bag quality and clarified the causes of the cross contamination.

Techniques that can increase the SI- engine efficiency while keeping the emissions very low is to reduce the engine displacement volume combined with a charging system. Advanced systems are needed for an effective boosting of the engine and today 1D engine simulation tools are often used for their optimization. This thesis concerns 1D engine simulation of a turbocharged SI engine and the introduction of CFD computations on components as a way to assess inaccuracies in the 1D model. 1D engine simulations have been performed on a turbocharged SI engine and the results have been validated by on-engine measurements in test cell. The operating points considered have been in the engine’s low speed and load region, with the turbocharger’s waste-gate closed. The instantaneous on-engine turbine efficiency was calculated for two different turbochargers based on high frequency measurements in test cell. Unfortunately the instantaneous mass flow rates and temperatures directly upstream and downstream of the turbine could not be measured and simulated values from the calibrated engine model were used. The on-engine turbine efficiency was compared with the efficiency computed by the 1D code using steady flow data to describe the turbine performance. The results show that the on-engine turbine efficiency shows a hysteretic effect over the exhaust pulse so that the discrepancy between measured and quasi-steady values increases for decreasing mass flow rate after a pulse peak. Flow modeling in pipe geometries that can be representative to those of an exhaust manifold, single bent pipes and double bent pipes and also the outer runners of an exhaust manifold, have been computed in both 1D and 3D under steady and pulsating flow conditions. The results have been compared in terms of pressure losses. The results show that calculated pressure gradient for a straight pipe under steady flow is similar using either 1D or 3D computations. The calculated pressure drop over a bend is clearly higher1D engine simulations of turbocharged engines are difficult to using 1D computations compared to 3D computations, both for steady and pulsating flow. Also, the slow decay of the secondary flow structure that develops over a bend, gives a higher pressure gradient in the 3D calculations compared to the 1D calculation in the straight pipe parts downstream of a bend. / QC 20101119