Bc. Jaroslav Simcik Construction of hydraulic wood-splitting machine DP, Institute of production machines, systems and robotics, 2010, p. 60, fig. 30, appendices 7, This master ´s thesis is concerned with the wood-processing technology with a focus on the construction of hydraulic wood splitter machine with a force 120 kN.

This thesis covers the design and the construction of vehicle, which is powered by pressured fluid. The vehicle has driving system based on mechanical – hydraulic recuperation of kinetic energy during braking of vehicle. Her secondary part is used only by the start of vehicles. The thesis describes possibilities of kinetic energy recovery and in more detail explaines kinetic energy recovery with use of hydraulic systems and their practice use. The main part of the thesis contains a design of hydromobil with demonstration of individual options in outline. The selection of the whole hydraulic connection and transmission is described in detail as well as the construction of particular components of the vehicle.

A common problem in the design of hydraulic systems is the pressure losses caused by movement of viscous liquid in individual elements of hydraulic circuits. These losses have negative effects on the overall efficiency of hydraulic systems and thus their overall operation. There is a change in temperature of working fluid and components (elements) of circuit due to the result of the mentioned losses. This master thesis is focused on the heat generation (output) in hydraulic cubes of a linear integrated hydraulic cubes (here in after LIHJ) which is the prototype of hydraulic lifting equipment. Losses, arising during the operation LIHJ in pipes and in hoses, can be determined numerically and experimentally. Most of hydrostatic transmitters and others hydraulic components are almost always supplied with the necessary documentation which contains all the necessary information such as experimental characteristics, etc. However problematic parts are the hydraulic blocks which are specific to their size and function. Of course, each manufacturer must prepare technical documentation including characteristics which are important for trouble-free operation of the hydraulic system. The main aim of this work is to determine pressure losses and the heat generation (output) in the hydraulics blocks by program which is used for creating geometry and computing using software like Ansys Fluent, which is based on the finite element method. If these calculations could be compared with experimental measurement technically, then heat generation (output) in both the cubes will be evaluated towards other hydraulic components and the whole system (device). The simulation results will be implemented in software which is used for calculation of heat generation in LIHJ at different operating modes and loads. Furthermore, these results will be the basis for the design of geometry of hydraulic blocks with low pressure losses which will reduce energy consumption of the device. At the end of this thesis, some advanced methods for the manufacturing of hydraulic blocks are briefly introduced, namely the method 3-D casting.

Purpose of this thesis is to make constructional modification of single-purpose pressing machine for Huisman Konstrukce, s.r.o. company. Present machine is non-operational and not enough powerful for present requests of workshop. Intended modifications are to describe present condition of machine, find present requirements and design simple modifications. All modifications are checked by calculations and sketched in shop drawings. There were also made alternative options of modification to show machine more versatile and automatic.

This thesis deals with the design of the hydraulic system of hydraulic crane. It focuses on the description of the individual elements of the existing hydraulic system, analysis of forces, calculate diameters of linear hydraulic motors and their pressures and flow rates.

This work describes the design of a dedicated three-rolls hydraulic bending for Hardox 500 without the possibility of bending sheet metal for the manufacture of pipes. The work will analyze the problem of proposed three-rolls bending, bending technology and creating of the pre-bending, the design of the adjusting hydraulic servo-cylinder, planetary gearboxes with hydraulic motors to drive the bottom rollers, a partial draft of the hydraulic circuit and the complete frame structure of bending machine with its covers.

The Ph.D. thesis deals with the preparation of highly hydraulic binders based on roman cement. Roman cement (natural cement) is recently not available on the market due to uneconomic production of such a specific binder. On the other hand there is a big lack of information on this hydraulic binder. These results in failure in meeting the basic principle of modern approaches to restoration of historical buildings or monuments made of such kind of materials, which is such, that the materials used for restoration should be compatible with original material. Recognition of the processes of roman cement preparation based on progressive methods of study can provide substantial information for more efficient raw material selection or even for nontraditional utilization, for example for artworks. This work hence is aimed at studying and selection of traditional natural as well as nontraditional raw materials such as clay. This work also studies the preparation of highly hydraulic binders based on roman cement and the kinetics of burning and hydration processes

L'importance des enjeux liés à la qualité et à la connaissance de l'eau souterraine nécessite de caractériser le fonctionnement des nappes d’eaux souterraines. En hydrogéologie, les méthodes qui permettent de réaliser le modèle conceptuel d’un aquifère reposent généralement sur l’observation et la caractérisation du milieu, à partir notamment de la mise en place de forages et la réalisation de pompages d’essai. Cependant, ces méthodes présentent des limites pour caractériser la variabilité spatiale des aquifères hétérogènes. Dans cette thèse, nous nous sommes intéressés au développement d’approches expérimentales qui utilisent des informations issues de traçage thermique ou salin pour la caractérisation des paramètres hydrauliques des milieux hétérogènes poreux. Ce choix expérimental a été justifié 1) par les difficultés de prise en compte des hétérogénéités hydrauliques dans les milieux poreux naturels et 2) pour une meilleure compréhension des phénomènes mis en jeu en situation contrôlée. Dans les travaux réalisés, nous avons tout d’abord proposé d’utiliser des mesures thermiques ponctuelles, puis obtenues dans l'infrarouge thermique pour estimer les paramètres hydrauliques en milieux poreux hétérogènes. Cependant, les méthodes de traçage thermiques étant limitées dans les zones faiblement perméables, nous avons fait évoluer notre approche en la combinant avec une méthode géophysique (Potentiel Spontané). Cette méthode, sensible aux écoulements des fluides et aux processus thermoélectrique et électrochimique, nous a permis de collecter des données temporelles intéressantes pour surveiller des variations thermiques ou saline provoquées dans les milieux. Les mesures obtenues ont été par la suite utilisées dans des algorithmes d’inversion pour estimer les distributions spatiales des propriétés hydrauliques. Les résultats obtenus nous ont permis de montrer l’efficacité de ces approches pour la caractérisation des milieux hétérogènes et par conséquent pour la modélisation des écoulements des fluides dans ces milieux. / The importance of issues related to the quality of groundwater requires characterizing the operation of groundwater aquifers. Hydrogeological methods used to carry out conceptual model of an aquifer are generally based on the observation and characterization of the medium, by using boreholes and carrying out of pumping test operations. However, these methods present some limitations in characterizing the spatial variability of heterogeneous aquifers. In this thesis, we develop experimental approaches that use information from thermal or saline tracing for the characterization of hydraulic parameters in heterogeneous porous media. The choice of using experimental approaches was justified 1) by difficulties of taking into account hydraulic heterogeneities in natural porous media and 2) for a better understanding of the phenomena involved in a controlled situation. In this work, we first proposed the use of punctual thermal measurements, then measurements obtained by using thermal infrared to estimate hydraulic parameters in heterogeneous porous media. However, as thermal tracing methods are limited in low permeability areas, we improved our approach by combining it with a geophysical method (Spontaneous Potential). This method, sensitive to fluid flows and thermoelectric and electrochemical processes, has allowed us to collect interesting temporal data to monitor thermal or saline variations in the media. The measurements obtained were then used in inversion algorithms to estimate the spatial distributions of hydraulic properties. The results obtained allowed to demonstrate the effectiveness of these approaches for the characterization of heterogeneous media and consequently for the modelling of fluid flows.

The paper describes the comparison and the difference of modern hydraulic fluids compared to conventional hydraulic fluids. A comparison of different base oil groups, solvent neutrals, group I and comparison with hydrotreated/hydroprocessed group II and/or group III base oils is presented. The influence on oxidation stability, elastomer compatibility, carbon distribution and physical properties is outlined.

Hydraulic tanks have a variety of different tasks. The have to store the volume of oil needed for asymmetric actors in the system as well as to supply the system with preconditioned oil. This includes the deaeration as air contamination is affecting the overall system performance. The separation of the air in the tank is being realized mainly by passive methods, improving the guidance of the air and oil flow. The use of CFD models to improve the design of hydraulic tank is recently often discussed. In this paper, a design method for hydraulic tanks using CFD is presented and discussed. First the different requirements on a hydraulic tank are described as well as the motivation changing the tank designs. Additionally, a quick overview on different calculation models for the behavior of air in oil as well as the capabilities of CFD to reproduce them is given. After this the methodology of tank design applying CFD is presented. The method is then used in an example.