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The article presents an innovative solution for developing of a stand on which both pumps and hydraulic motors are tested. The functional innovation of the stand is represented by the fact that the driving of the tested pump is made by the motor under tests, and the load on the shaft of the motor to be checked is provided by the checked pump. [ABSTRACT FROM AUTHOR]

The cluster of excellence "Tailor-Made Fuels from Biomass" at RWTH Aachen University is identifying and investigating new potential biofuel candidates. Fuel candidates developed in this process greatly vary in rheological and hydrodynamic properties. One of the most important properties is the fluid viscosity. Low viscosities increase volumetric losses, friction and wear in the fuel pump, therefore lowering the overall efficiency. An optimization of the tribological contacts inside the pump is essential to ensure a sufficient performance. One of the most important tribological pairings is the piston-bushing contact which has a crucial impact on the leakage. A possibility to decrease this leakage is the hollow piston design developed for common-rail pumps. In common-rail injection pumps a reduced gap height can increase the volumetric efficiency by approximately 40% at 120 MPa injection pressure. In this paper, a first attempt is performed to transfer this specific hollow piston into hydraulic pumps. Thereby a possible application preferably operates at low viscosity and high bulk moduli. Relatively low volumetric efficiencies indicate hidden potential. Both of these cases can be found in water hydraulics. With a maximum pressure of 32 MPa radial piston units commonly operate at 25 % of the common rail system´s pressure level. Investigating possible applications of the hollow piston principle for water hydraulics, various potential piston geometries of a radial piston unit are simulated using FEM analysis. In order to ensure an optimal geometry, geometrical approaches are discussed and applied to the hollow piston as well as simulated with a Matlab model using the Reynolds equation regarding the resulting leakage and potential increase in volumetric efficiency. [ABSTRACT FROM AUTHOR]

This paper reviews the techniques for analyzing the Noise Control in Hydraulic System components. Hydraulic power transmission was quieter than the gears, cams, connecting rods, and cables that replaced. However, as economics led to higher pressures and speeds, it also led to less beefy components. Power levels of machines also grew rapidly. All of these factors increased noise. Hydraulic machines generally have a number of noise sources. This paper explains how Pumps, Motors and Valves generate airborne, structure-borne, and fluid-borne noises. It identifies hydraulic parameters that influence noise and guide planning programs for designing and developing of some quiet hydraulic components. Economics requires that all quieting efforts be focused on identifying and controlling the key noise generator. [ABSTRACT FROM AUTHOR]

A cryogenic over-pressure pump (OPP) was tested in the prototype telescope liquid nitrogen (LN2) cooling system for the Dark Energy Survey (DES) Project. This OPP consists of a process cylinder (PC), gas generator, and solenoid operated valves (SOVs). It is a positive displacement pump that provided intermittent liquid nitrogen (LN2) flow to an array of charge couple devices (CCDs) for the prototype Dark Energy Camera (DECam). In theory, a heater submerged in liquid would generate the drive gas in a closed loop cooling system. The drive gas would be injected into the PC to displace that liquid volume. However, due to limitations of the prototype closed loop nitrogen system (CCD cooling system) for DECam, a quasiclosed- loop nitrogen system was created. During the test of the OPP, the CCD array was cooled to its designed set point temperature of 173K. It was maintained at that temperature via electrical heaters. The performance of the OPP was captured in pressure, temperature, and flow rate in the CCD LN2 cooling system at Fermi National Accelerator Laboratory (FNAL). [ABSTRACT FROM AUTHOR]

Major energy consumers as pumping stations from water networks and irrigations systems should be used in optimal conditions without undesirable events that cause malfunction of the equipments. The subject of this study highlights the possible diagnosis by measuring noise, vibration and pulsations in pipe because of cavitations or unstable operation. [ABSTRACT FROM AUTHOR]

Lack of electricity and water, the two fundamental resources in modern societies, is still a major issue in many developing countries and remote areas. This paper proposes a standalone renewable power system to solve the energy and water shortage in remote areas with abundant solar energy. The system utilizes a photovoltaic (PV) panel as the main energy source, which is controlled by a maximum power point tracking (MPPT) technique. A battery pack is used as the main energy storage device to smooth the fluctuation of solar power and to mitigate load transients and variations. In addition, a hydro storage system is used for water storage and supply, and also for supplying extra electric power via a hydro-turbine generator. The electricity and water demand of three households are considered for the system. The system modeling, unit sizing, control, simulation studies and the actual hardware implementation are presented and discussed in the paper. [ABSTRACT FROM PUBLISHER]

Still in the rural areas of Rajasthan, India, people are using conventional methods to fetch water from the wells or boreholes. Conventional methods like using animals, which circles around the well to fetch the water are still in use. This paper provides the use of Solar energy to produce electricity to run the water pump for fetching water from well. The paper is based on the theoretical prospect of designing a solar pumping system considering the aspects of Dynamic head, economic feasibility, water requirement and solar irradiance. The theoretical study shows that the proposed system's cost recovery time is half of the life time of system. All the calculations are theoretical [ABSTRACT FROM PUBLISHER]

All Kosovo mines have undergone the different declines and degradations in transition period. Some of the underground mines have also undergone the flooding under water as a result first of the war in Kosova, because of the damage of dewatering system, the lack of investments and disorganisation of mine's management, undefinition of the ownership status of mines, the interference of peoples interest, the ownership status, the resource of no one without any care at all, the transfer from the monist system to the market economy, the expel of the employees because of the ethnicity concretely of Albanians from the Milosevic regime because they were the pillar of the mine's functions, "raub" exploitation by the regime side with the war logic, the 20 year lack of the professional personnel, non-maintenance of dewatering system and their emplacement in function today for tomorrow, ad-hoc. But, the one that was inevitable was the water flood because of the lack of the protection water system of connective objects with surface, shaft, pump station, acting space. After the war of 1999 with all the dewatering efforts because of the above mentioned flood it has become too difficult due to the difficult regime of work, and increase of the risk level for working teams, the limited action space. Now it shall be used the special submersible pump, differing from the stationary pumps. Mounting and their function requires a special care. Their force should be calculated and selected by care and with special dedication in cooperation with specialists of these subjects of dewatering. We, as Independent Commission for Mines, are going through an analysis of a dewatering a mine, to create there also the modeling of organizing the dewatering, such we have now 5 of these, however, we are focused on that that it requires the stronger efforts for solution. [ABSTRACT FROM AUTHOR]

We attempt to reveal the unsteady three-dimensional flow structure in a suction sump with the vertical-wet-pit-pump configuration. In the present study, we consider the simultaneous measurement of a three-dimensional particle tracking velocimetry (3D-PTV) with another velocimetry, that is, an ultrasonic velocity profiler (UVP), using common tracer particles. This simultaneous measurement is expected to be a suitable method for the accuracy check of the 3D-PTV. At first, we have successfully found the suitable condition for simultaneous measurements with high accuracy. Then, we have revealed the concerning unsteady three-dimensional flow structure at various instants, quantitatively. [ABSTRACT FROM AUTHOR]

Turbo-pumps have weak points, such as the pumping operation becomes unstable in the rising portion of the head characteristics and/or the cavitation occurs at the low suction head. To overcome simultaneously both weak points, the authors invented the unique pump unit composed of the tandem impellers and the counter-rotating type motor with the double rotational armatures. The front and the rear impellers are driven by the inner and the outer armatures of the motor, respectively. Both impeller speeds are automatically and smartly adjusted in response to the pumping discharge. Such speeds controlled smartly contribute pretty well to suppress not only the unstable performances at the low discharge but also the cavitation at the high discharge, as verified in the previous paper. Continuously, the effects of the impeller profiles not only on the pump performances but also on the rotational behaviors are discussed in this paper. Two kinds of the blade profile, giving the lower and the higher heads, were prepared as the front and the rear impellers. The pump performances and the both impeller speeds are affected undoubtedly by not only the discharge but also the impeller profiles. The rotational speed of the front impeller is faster than the speed of the rear impeller in the wide discharge, while the tandem impellers composed of the front impeller giving the lower head and the rear impeller giving the higher head. Such behaviors are caused by making the angular momentum change through the front impeller coincide with that through the rear impeller. [ABSTRACT FROM AUTHOR]

The specifics of high-performance centrifugal pumps operation are analyzed. According to the accumulated vibration monitoring data the reasons of vibration increase are analyzed and the factors which effect this increasing. The correlation analysis is applied to prior detection of pump fault. [ABSTRACT FROM AUTHOR]

NASA's vision for Space Exploration that would return humans to the Moon by 2020 in preparation for human explorations of Mars. This requires innovative technical advances. The lunar mission requires a temperature-lift (heat pump) technology to reject waste heat to hot lunar surface (heat sink) environments during lunar daytime. The lunar outpost and Lunar Surface Access Module (LSAM) to operate anywhere during the hot lunar daytime require a high performance and energy-efficient, yet reliable refrigeration technology. A vapor compressor-driven hybrid two-phase loop was developed for such high temperature-lift applications. The vapor compression loop used an advanced porous wick evaporator capable of gravity-insensitive capillary phase separation and excess liquid management to achieve high temperature-lift, large-area, isothermal and high heat flux cooling capability and efficient compression. The high temperature lift will allow the lunar surface systems use compact radiators by increased heat rejection temperature. [ABSTRACT FROM AUTHOR]

The paper discusses an advanced hybrid two-phase loop technology for spacecraft thermal management. The hybrid loop integrates active mechanical pumping with passive capillary pumping promising a reliable yet high performance cooling system. The advanced evaporator design using porous wick structures was developed for the hybrid loop to enhance boiling heat transfer by passive phase separation. The prototype testing using various hybrid loops and components demonstrated that the hybrid loop was capable of removing high heat fluxes from multiple heat sources with large surface areas up to 135 cm2. Because of the passive capillary phase separation, the hybrid loop operation doesn’t require any active flow control of excess liquid in the evaporator, even at highly transient and asymmetrical heat inputs. These performance results represent significant improvements over state-of-the-art heat pipes, loop heat pipes and evaporative spray cooling devices in terms of performance, robustness and simplicity. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]