The Experts below are selected from a list of 21885 Experts worldwide ranked by ideXlab platform

Elise Le Rouzic - One of the best experts on this subject based on the ideXlab platform.

Yin Xiaochu - One of the best experts on this subject based on the ideXlab platform.

  • Mixing performance of PS /HDPE blends in a Positive Displacement flow type vane extruder
    Materials Science and Technology, 2014
    Co-Authors: Yin Xiaochu
    Abstract:

    The PS / HDPE melt blending experiments were conducted with a self-made Positive Displacement flow type vane extruder. Samples obtained at four sampling locations along extrusion direction were used to characterize by tensile test and SEM. The influences of rotating speed and sampling location on mechanical properties and morphology of the composites were studied. The experimental results showed that the longer the distance from the feed inlet the tensile strength of the blends increased. The tensile strength increased rapidly first and then remained almost unchanged. The higher of the rotating speed the tensile strength increased faster. With the increase of rotator speed,the tensile strength at the fixed sampling location increased rapidly first and then slowly. There was an optimum rotator speed. As shown in the SEM photographs the dispersed phases of PS were ellipsoidal shaped in continuous phase. The particle size decreased rapidly first along extrusion direction and then decreased slowly. Materials can be mixed homogeneously within short thermo-mechanical history in a Positive Displacement flow type vane extruder. The mixing efficiency can be increased with this type of extruder.

Myung Rae Cho - One of the best experts on this subject based on the ideXlab platform.

  • Vane tip detachment in a Positive Displacement vane pump
    KSME International Journal, 1998
    Co-Authors: Myung Rae Cho
    Abstract:

    This paper reports on the theoretical study of the transient chamber, pressure and vane motion in a Positive Displacement vane pump which widely used in the automotive power steering systems. For analyzing the vane detachment, dynamic equation of vane motion and flow continuity equations are derived and then solved simultaneously using the numerical integration. Vane detachment is shown to be a function of the chamber pressure, rotational speed, and the design geometry of pump. Vane detachment occurs due to excess compression of chamber volume, and it can be reduced by adjustment of design parameters. Specially, silencing V-groove in side plate and radius reduction ratio of compression zone in the cam ring are important design factors for reducing the vane detachment.

Leroy L Knobel - One of the best experts on this subject based on the ideXlab platform.

  • sampling for purgeable organic compounds using Positive Displacement piston and centrifugal submersible pumps a comparative study
    Ground Water Monitoring and Remediation, 1993
    Co-Authors: Leroy L Knobel
    Abstract:

    Positive-Displacement piston pumps that minimize sample agitation have no apparent advantage over centrifugal submersible pumps when used to collect ground water samples for analysis of low concentrations of purge-able organic compounds. Analytical uncertainties inherent in laboratory environments appear to influence analytical results of low-concentration purgeable organic compound samples more than either pump type or sampling team. Centrifugal submersible pumps are at least equally efficient as Positive-Displacement piston pumps in the recovery of carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, and chloroform after sampling and analytical influences are made constant.

  • Sampling for Purgeable Organic Compounds Using Positive‐Displacement Piston and Centrifugal Submersible Pumps: A Comparative Study
    Groundwater Monitoring & Remediation, 1993
    Co-Authors: Leroy L Knobel, Larry J. Mann
    Abstract:

    Positive-Displacement piston pumps that minimize sample agitation have no apparent advantage over centrifugal submersible pumps when used to collect ground water samples for analysis of low concentrations of purge-able organic compounds. Analytical uncertainties inherent in laboratory environments appear to influence analytical results of low-concentration purgeable organic compound samples more than either pump type or sampling team. Centrifugal submersible pumps are at least equally efficient as Positive-Displacement piston pumps in the recovery of carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, and chloroform after sampling and analytical influences are made constant.

Bruce Davies - One of the best experts on this subject based on the ideXlab platform.

  • Valve dynamics in multi-cylinder Positive Displacement pump model
    2015 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2015
    Co-Authors: Aleksandar Josifovic, Jonathan Corney, Bruce Davies
    Abstract:

    Pumps are critical components of many industrial processes. Although they vary in size, depending on the application, their operating principles and performance parameters are similar across generic families. Large industrial Positive Displacement (P.D.) pumps, primarily used in mining, oil and gas industries, deliver significant amounts of flow coupled with very high pressures. However, increasing energy costs and sustainability concerns demand systems re-design to improve their efficiency. Most established forms of PD pumps have duty cycles fixed by the movement of spring loaded valves. One approach to increase their energy efficiency could be to dynamically vary the movement of these valves. To test this hypothesis and quantify any potential benefits a computational model is required. This paper introduces modelling technique used to analytically describe a multi-cylinder Positive Displacement pump. A hybrid modelling approach is described which incorporates analytical relationships, the results of CFD simulation and experimental values. Results show how different valve actuation responses affect the overall flow rate of the pump. The results presented in the paper clearly indicate future development steps for improved control of Positive Displacement pumps.

  • AIM - Valve dynamics in multi-cylinder Positive Displacement pump model
    2015 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2015
    Co-Authors: Aleksandar Josifovic, Jonathan Corney, Bruce Davies
    Abstract:

    Pumps are critical components of many industrial processes. Although they vary in size, depending on the application, their operating principles and performance parameters are similar across generic families. Large industrial Positive Displacement (P.D.) pumps, primarily used in mining, oil and gas industries, deliver significant amounts of flow coupled with very high pressures. However, increasing energy costs and sustainability concerns demand systems re-design to improve their efficiency. Most established forms of PD pumps have duty cycles fixed by the movement of spring loaded valves. One approach to increase their energy efficiency could be to dynamically vary the movement of these valves. To test this hypothesis and quantify any potential benefits a computational model is required. This paper introduces modelling technique used to analytically describe a multi-cylinder Positive Displacement pump. A hybrid modelling approach is described which incorporates analytical relationships, the results of CFD simulation and experimental values. Results show how different valve actuation responses affect the overall flow rate of the pump. The results presented in the paper clearly indicate future development steps for improved control of Positive Displacement pumps.

  • Modeling a variable speed drive for Positive Displacement pump
    2014 IEEE ASME International Conference on Advanced Intelligent Mechatronics, 2014
    Co-Authors: Aleksandar Josifovic, Jonathan Corney, Bruce Davies
    Abstract:

    Positive Displacement pumps are critical to applications ranging from drug delivery to water jet cutters. The reciprocating motion of these pumps means that their output inevitably pulses at the rate proportional to the speed of the drive. However, if the constant speed drive, traditionally employed in PD pumps, is replaced by one that can dynamically vary speed and torque the possibility of controlling the form of the output pulses arises. To enable such a system this paper reports the modeling of a drive train connected to a Positive Displacement Pump. The drive train comprises a internal combustion engine to generate rotary power, a gearbox transmission to enable changes in the speed-torque ratio and a hydrodynamic coupling in between the two to accommodate flexible power flow. The behavior of the swept pumping volume is generated from a parametric model derived from a CFD analysis. The result demonstrates that there is a significant difference in the flow predicted by models that use average, rather than instantaneous speeds.