This chapter discusses a modeling and passivity based control of hydraulic arms which are robotic, that is, have asymmetric cylinders. Hydraulic arms are very important components in field robotics, such as construction, agriculture, rescue , demining robotics and so on since hydraulic arms are superior to electric arms with respect to the power to weight ratio and also can keep joint forces ev...

In this report, I talk about my work on fluid simulation and erosion simulation. First some background knowledge about both fluid and hydraulic erosion simulation is discussed and then some technical details about a levee erosion simulator is presented. Some implementation results of the system are also presented and discussed. Finally, I will also discuss the difficulties I faced when doing th...

In this study, variable injection-rate technology was numerically investigated in a pre-existing discrete fracture network (DFN) formation, the Tarim Basin in China. A flow-stressdamage (FSD) coupling model has been used in an initial attempt towards how reservoir response to variable injection-rates at different hydraulic fracturing stages. The established numerical model simultaneously consid...

1.0 Introduction Hydraulic fracturing, the process of initiation and propagation of a crack by pumping fluid at relatively high flow rates and pressures, is one of several techniques for creating cracks in rock. Fractures in the earth's crust are desired for a variety of reasons, including enhanced oil and gas recovery, re-injection of drilling or other environmentally sensitive wastes, measure...

Short-term changes in the hydraulic head of surface water bodies are known to influence the shallow response of hydraulically connected groundwaters. Associated with these fluctuations is the physical increase in stream water creating a mechanical load on the ground surface. This load is supported by the geologic materials (sediment or rock) and the pore fluid contained within the pores. Change...

This paper focuses on the implementation, validation and exploitation of a vertical dropshaft flow operation using the commercial VOF-based Computational Fluid Dynamics (CFD) code, FLOW-3D ® . Using the experimental data of Chanson (2002), the package was used to simulate the flow patterns in a rectangular dropshaft with plunge-flow pattern. Both k−ε and k−ε RNG turbulence closures were tested ...

This paper is motivated by the need to develop low cost, wireless velocity sensors for hydraulic research and application in streams. A velocity bend sensor (VBS) is a flexible plastic polyimide substrate sheet with an electronic resistor connected to a voltage divider. Drag of a moving fluid bends the sensor, changes the electronic resistance, and produces a voltage drop that can be related to...

Critical submergence in pumping systems can be determined using a number of calculations, all of which result from heterogeneous geometries based on water. The most widely spread critical submergence formula is that of the Hydraulic Institute. A study, carried out in Germany, looked at eight different formulations used to calculate critical submergence, comparing their results with those of a h...

In the framework of the ASCHLIM project, a group of European experts in thermal hydraulic calculation has been clustered to evaluate the state of the art of CFD (Computational Fluid Dynamics) codes applied to ADS designs. The work of this group, supported by the Vth Framework Program of the European Union, has been focused on CFD analysis of the experiments that includes thermal hydraulic pheno...

Aircraft hydraulic systems are composed of several components connected and distributed along the aircraft. Monitoring leakage of these components are time consuming tasks, and often cover only some parts of the system. The objective of this work is to present a method to estimate hydraulic leakage and recommend maintenance and servicing tasks using aircraft standard sensors such as fluid tempe...