Um eine zielgerichtete Ableitung von Fahrzeugeigenschaften in frühen Entwicklungsphasen zu ermöglichen, ist eine Subsystemebene erforderlich, die eine konzeptunabhängige Auslegung des Gesamtfahrzeugverhaltens zulässt. In der vorliegenden Arbeit wird daher eine neue Methodik zur Auslegung von Fahrkomfort-Kennwerten auf Basis von Subsystemeigenschaften vorgestellt. Neben der Entwicklung eines geeigneten Modellansatzes, in dem die Subsysteme des Gesamtfahrzeugs durch Greybox-Modelle ohne Komponentenbezug miteinander verknüpft werden, stehen dabei auch dessen Parametrierung sowie die Integration der Methodik im Entwicklungsprozess im Vordergrund. Zur Ableitung der damit verbundenen physikalisch-mechanischen Zusammenhänge werden statische und dynamische Achsprüfstände sowie Simulationen eingesetzt. Die Anwendung der Methodik lässt eine gezielte Eigenschaftsableitung zwischen Gesamtfahrzeug-, Subsystem- und Komponentenebene im Fahrkomfort zu, bei der die Subsystemebene als neue Referenz für die Ableitung von Komponenteneigenschaften dient. Weiterhin erlaubt das Vorgehen eine eigenschaftsbasierte Vorauswahl optimaler Komponentenkonzepte sowie detaillierte Wettbewerbsanalysen. Dadurch wird eine nachhaltige Steigerung der Effizienz im Entwicklungsprozess des Fahrkomforts ermöglicht.

A supersonic ejector is used to pump a secondary gas using a supersonic primary gas flow by augmentation of momentum and energy in a variable area duct. The internal compressible flow through an ejector has many complex gas dynamic features, like compressible shear layers and associated shock interactions. In many practical applications, ejectors are operated in the choked flow regimes where higher operating pressure ratios and mass flow rates are encountered. On the other hand, rather low entrainment and subsonic secondary flow dynamics (referred as the mixed regime of operation) dominate the dilution and purging applications of ejectors. The fundamental understanding of the flow dynamics associated with gaseous mixing process in the ejector especially in the mixed operational regime is still unclear. Obtaining a comprehensive understanding of the flow through a supersonic ejector in the mixed regime through experimental investigations is the prime focus of the present study. A new supersonic ejector test facility is designed, fabricated and established in the laboratory during the course of this study. The effects of using different gases in the secondary flow have been investigated. Two novel methods to improve the ejector by enhancing mixing are also implemented. Optical diagnostic tools (Time-resolved Schlieren and laser scattering) and wall static pressure measurements are used to investigate the dynamics of mixing process inside the ejector. State of the art image processing codes are developed to determine the length in the ejector for which the primary and the secondary flows are separate, referred here as the non-mixed length from the results of the flow visualization studies. Exhaustive experiments are carried out on the two dimensional rectangular supersonic ejector by varying the mass flow rates of primary and secondary flows, primary stagnation pressure, for two locations of the nozzle in the ejector. The non-mixed length determined from quantitative flow visualization tools is found to lie within 4.5 to 5.2 times the height of the duct (20 mm). The non-mixed flow length determined from flow visualization studies corroborates well with the wall static pressure measurements. A significant reduction of non-mixed length of about 46.7% is caused by shock wave-boundary layer interactions in the supersonic nozzle at over-expanded conditions. Further, the effects of differences in molecular weight and ratio of specific heats on the performance are also studied using cylindrical supersonic ejector at low entrainment ratios (0.008 to 0.06). In these studies air is used as the primary fluid while argon and helium are used in the secondary flow segment of the ejector. The results indicate that Argon has better entrainment characteristics compared to helium. Two novel supersonic nozzles (the tip rig nozzle and Elliptic Sharp Tipped Shallow lobed nozzle) are also devel- oped to enhance mixing in the ejector. About 30% enhancement of entrainment ratio is observed with the newly designed nozzle geometries. Illustrative numerical simulations are also carried out to complement the experimental studies.

Ce travail de thèse concerne l'étude d'extracteurs d'air hybrides éoliens. Il se décompose en des investigations amont et appliquées. Dans la partie amont, des simulations fines ont été effectuées en conduite carrée avec et sans rotation, pour des nombres de Reynolds turbulents de l'ordre de 600, afin d'analyser l'impact de la rotation sur la turbulence. Elles ont montré que la rotation rompt la symétrie de l'écoulement. La partie appliquée est dédiée à la conception d'une nouvelle géométrie d'extracteur d'air. Cette géométrie a été proposée à partir de l'analyse de simulations RANS. Ses performances ont été confirmées par des mesures expérimentales sur banc d'essais. Les tests en soufflerie d'un système de captage d'énergie éolienne, conçu pour l'extracteur, ont mis en évidence son adéquation au régime de fonctionnement de l'extracteur. Les essais expérimentaux de l'extracteur complet, montrent que le système de captage apporte une part significative de l'énergie. Des essais en soufflerie ont permis d'observer le comportement global de l'extracteur. / This PhD work concerns the study of hybrid air extractors. It is composed of upstream and applied investigations. In the upstream part, fine simulations are realized in square duct flow with and without rotation to analyse the impact of rotation on turbulence. It is found that rotation removes symmetry property of the flow with turbulent Reynolds number of 600. The applied part is dedicated to the conception of a new air extractor geometry. This geometry is proposed from the analyse of RANS simulations. Its performances are confirmed by experimental measurements on test rig. Wind tunnel tests of a wind power capturing system, designed for the extractor, show a good adequation to the operating regime of the extractor. Experimental investigations on the complete air extractor, show the wind power capturing system brings a significant part of the energy. Wind tunnel tests allow to observe the complete air extractor behaviour.

The thesis deals with the design of the experimental testing rig. Test rig is designed to measure NVH transmission parameters. First, basic knowledge of vibro-acoustic measurement is discussed. This is followed by an evaluation of the most commonly used power devices to derive real loads on measured gearboxes. In more detail, a back-to-back test rig is disassembled among other things. In the thesis are described two main components, which are composed of a connecting element and a test bench. Both components were optimized during the design due to their modal properties. Numerical modal analysis was performed in ANSYS Workbench software. The thesis also includes strength calculations performed using both numerical and analytical approaches. The indispensable result of the design work is the complete drawing documentation. Finally, measurements of vibrations and noise on the physically made connecting element assembly have been performed and subsequently evaluated.

This diploma thesis deals with the design of several variants of test rig for tests of axial ball joints of passenger cars. The individual design variants are evaluated based on the evaluation matrix and then the best option is selected. Selected proposal includes a complete design including 3D models and strength analyses that focus on the most stressed construction nodes. These design nodes are solved using the finite element method. Hydraulics and hydraulic elements are equipped by the existing equipment from a test lab. At the end of this thesis is solved risk analysis of the new construction and its economic evaluation.

The master thesis deals with design of test rig for long-term testing of coupling appointed to railway vehicles. At first, there is made a brief research which is related to railway coupling used for transmitting a torque. This is followed by an analysis of the most used power devices to derive real loads conditions of tested couplings. There is chosen the most appropriate conception based on made analysis and it is followed by the description of designed components. There is made a verification of modal properties non-purchased components which is necessary part of the thesis. Numerical modal analysis was performed in ANSYS Workbench software. In the end of the thesis there are included stress-strain analysis of the chosen designed components.

This thesis deals by the design of 1/4 car model for testing vehicle dampers, which can be used to simulate the real suspension of a vehicle wheel (up to a maximum car weight of 1,970 kg) and the so-called linear wheel suspension. A linear mathematical 1/4 car model with 2 DOF (Degrees Of Freedom) and data from literature search are used to design and derive the basic parameters of the device. The thesis contains a description of the linear mathematical model and its outputs (acceleration of the sprung mass and forces acting on the sprung mass), description of designed device, descriptions of created simulations (static, modal and harmonic analysis in ANSYS Workbench 2020 R2) and conceptual design of the modifications this device for another possible use for testing of bicycles.

My diploma thesis describes upgrade of flowbench serving as test rig for regulation valves characteristic measurement. At the beggining, there is an introduction to the water regulation valves theory followed by current machine condition description. Next chapter defines needed improvements and at the end follows proposition of improvements and necessary component definition and final realization. Final chapter summarizes complete project.

My diploma thesis describes upgrade of flowbench serving as test rig for regulation valves characteristic measurement. At the beggining, there is an introduction to the water regulation valves theory followed by current machine condition description. Next chapter defines needed improvements and at the end follows proposition of improvements and necessary component definition and final realization. Final chapter summarizes complete project.

For the transport of their spacecraft from the vehicle assembly building to the launch pads at Kennedy Space Centre, Florida, the National Aeronautics and Space Administration (NASA) is using two special crawler transporters since 1965. First developed for the Saturn V rocket the crawler transporters have been sufficient for all following generations of space ships so far. But for the new generation of Orionspacecraft which is under development now, a load capacity increase for the crawler transporter of plus 50% was necessary. For this task Hunger Hydraulik did develop new jacking, equalizing and levelling (JEL) cylinders with sufficient load capacity but also with some new features to improve the availability, reliability and safety of this system. After design approval and manufacture of the cylinders they have been tested in a special developed one-to-one scale dynamic test rig and after passing this the cylinders had to prove their performance in the crawler transporter itself. This article describes the general application and introduces the technical requirements of this project as well as the realized solution.