The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform

Dohoy Jung - One of the best experts on this subject based on the ideXlab platform.

  • modelling and simulation of a dual clutch transmission vehicle to analyse the effect of pump selection on fuel economy
    Vehicle System Dynamics, 2010
    Co-Authors: Rahul Ahlawat, Hosam K. Fathy, Jeffrey L. Stein, Dohoy Jung
    Abstract:

    Positive Displacement Pumps are used in automotive transmissions to provide pressurised fluid to various hydraulic components in the transmission and also lubricate the mechanical components. The output flow of these Pumps increases with pump/transmission speed, almost linearly, but the transmission flow requirements often saturate at higher speeds, resulting in excess flow capacity that must be wasted by allowing it to drain back to the sump. This represents a parasitic loss in the transmission leading to a loss in fuel economy. To overcome this issue, variable Displacement Pumps have been used in the transmission, where the output flow can be reduced by controlling the Displacement of the pump. The use of these Pumps in automatic transmissions has resulted in better fuel economy as compared with some types of fixed Displacement Pumps. However, the literature does not fully explore the benefits of variable Displacement Pumps to a specific type of transmission namely, dual-clutch transmission (DCT), which has different pressure and flow requirements from an epicyclic gear train. This paper presents an analysis of the effect of pump selection on fuel economy in a five-speed DCT of a commercial vehicle. Models of the engine, transmission, and vehicle are developed along with the models of two different types of Pumps: a fixed Displacement gerotor pump and a variable Displacement vane pump. The models are then parameterised using experimental data, and the fuel economy of the vehicle is simulated on a standard driving cycle. The results suggest that the fuel economy benefit obtained by the use of the variable Displacement pump in DCTs is comparable to the benefit previously shown for these Pumps in automatic transmissions.

  • Effect of pump selection on fuel economy in a dual clutch transmission vehicle
    2009 American Control Conference, 2009
    Co-Authors: Rahul Ahlawat, Hosam K. Fathy, Jeffrey L. Stein, Dohoy Jung
    Abstract:

    Positive Displacement Pumps are used in automotive transmissions to provide pressurized fluid to various hydraulic components in the transmission and also lubricate the mechanical components. The output flow of these Pumps increases with speed, almost linearly, but the flow requirements often saturate at higher speeds resulting in the excess flow draining back to the sump. This represents a parasitic loss in the transmission leading to a loss in fuel economy. To overcome this issue, variable Displacement Pumps have been used in the transmission, where the output flow is reduced by controlling the Displacement of the pump. The use of these Pumps in automatic transmissions, has resulted in better fuel economy as compared to some types of fixed Displacement Pumps. However, the literature does not fully explore the benefits of variable Displacement Pumps to a specific type of transmission namely, dual-clutch transmission, that has different pressure & flow requirements than an epicyclic gear-train. This paper presents an analysis on the effect of pump selection on fuel economy in a five speed dual clutch transmission of a commercial vehicle. Models of the engine, transmission & vehicle are developed along with the models of two different types of Pumps: a fixed Displacement gerotor pump and a variable Displacement vane pump. The models are then parameterized using experimental data and the fuel economy of the vehicle is simulated on a standard driving cycle. The results suggest that the fuel economy benefit obtained by the use of the variable Displacement pump in dual clutch transmissions is comparable to that of automatic transmissions.

Jose Garciabravo - One of the best experts on this subject based on the ideXlab platform.

  • the determination of the theoretical stroke volume of hydrostatic Positive Displacement Pumps and motors from volumetric measurements
    Energies, 2019
    Co-Authors: Gijsbe Toe, Jack Johnso, Joh Montague, Ke Torres, Jose Garciabravo
    Abstract:

    This document presents a revised translation to the English language work developed more than 40 years ago by the first author. It further summarizes a common misinterpretation of the method and succinctly describes a graphical procedure to correctly determine the derived Displacement volume of a pump or a motor. The original work contains a directive for the determination of the derived Displacement volume of hydrostatic Positive Displacement Pumps and motors, from volumetric (flow and speed) measurements. The procedure is based on the definition of the derived displaced volume, defined as: The volumetric flow pushed or admitted by hydrostatic Positive Displacement Pumps and motors per (shaft) revolution, at zero internal and external leakage flow conditions.

Rahul Ahlawat - One of the best experts on this subject based on the ideXlab platform.

  • modelling and simulation of a dual clutch transmission vehicle to analyse the effect of pump selection on fuel economy
    Vehicle System Dynamics, 2010
    Co-Authors: Rahul Ahlawat, Hosam K. Fathy, Jeffrey L. Stein, Dohoy Jung
    Abstract:

    Positive Displacement Pumps are used in automotive transmissions to provide pressurised fluid to various hydraulic components in the transmission and also lubricate the mechanical components. The output flow of these Pumps increases with pump/transmission speed, almost linearly, but the transmission flow requirements often saturate at higher speeds, resulting in excess flow capacity that must be wasted by allowing it to drain back to the sump. This represents a parasitic loss in the transmission leading to a loss in fuel economy. To overcome this issue, variable Displacement Pumps have been used in the transmission, where the output flow can be reduced by controlling the Displacement of the pump. The use of these Pumps in automatic transmissions has resulted in better fuel economy as compared with some types of fixed Displacement Pumps. However, the literature does not fully explore the benefits of variable Displacement Pumps to a specific type of transmission namely, dual-clutch transmission (DCT), which has different pressure and flow requirements from an epicyclic gear train. This paper presents an analysis of the effect of pump selection on fuel economy in a five-speed DCT of a commercial vehicle. Models of the engine, transmission, and vehicle are developed along with the models of two different types of Pumps: a fixed Displacement gerotor pump and a variable Displacement vane pump. The models are then parameterised using experimental data, and the fuel economy of the vehicle is simulated on a standard driving cycle. The results suggest that the fuel economy benefit obtained by the use of the variable Displacement pump in DCTs is comparable to the benefit previously shown for these Pumps in automatic transmissions.

  • Effect of pump selection on fuel economy in a dual clutch transmission vehicle
    2009 American Control Conference, 2009
    Co-Authors: Rahul Ahlawat, Hosam K. Fathy, Jeffrey L. Stein, Dohoy Jung
    Abstract:

    Positive Displacement Pumps are used in automotive transmissions to provide pressurized fluid to various hydraulic components in the transmission and also lubricate the mechanical components. The output flow of these Pumps increases with speed, almost linearly, but the flow requirements often saturate at higher speeds resulting in the excess flow draining back to the sump. This represents a parasitic loss in the transmission leading to a loss in fuel economy. To overcome this issue, variable Displacement Pumps have been used in the transmission, where the output flow is reduced by controlling the Displacement of the pump. The use of these Pumps in automatic transmissions, has resulted in better fuel economy as compared to some types of fixed Displacement Pumps. However, the literature does not fully explore the benefits of variable Displacement Pumps to a specific type of transmission namely, dual-clutch transmission, that has different pressure & flow requirements than an epicyclic gear-train. This paper presents an analysis on the effect of pump selection on fuel economy in a five speed dual clutch transmission of a commercial vehicle. Models of the engine, transmission & vehicle are developed along with the models of two different types of Pumps: a fixed Displacement gerotor pump and a variable Displacement vane pump. The models are then parameterized using experimental data and the fuel economy of the vehicle is simulated on a standard driving cycle. The results suggest that the fuel economy benefit obtained by the use of the variable Displacement pump in dual clutch transmissions is comparable to that of automatic transmissions.

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.

  • 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.

Schlücke Eberhard - One of the best experts on this subject based on the ideXlab platform.

  • Cavitation In Reciprocating Positive Displacement Pumps
    Turbomachinery Laboratory Texas A&M University, 2011
    Co-Authors: Opitz Karste, Schade Olive, Schlücke Eberhard
    Abstract:

    LectureOwing to their impressive properties reciprocating Positive Displacement Pumps are used in many applications. Pumping fluids at high delivery pressures and metering are the areas of frequent use. The design of reciprocating Pumps requires an exact knowledge of the appearing phenomena such as unacceptable pipeline pulsation and harmful cavitation. But cavitation in reciprocating Positive Displacement Pumps is still an insufficiently understood problem. For a better understanding of the effects of incipient, partial and full cavitation in reciprocating Positive Displacement Pumps high-speed camera measurements were done under real operating conditions using a horizontal single-acting plunger pump. Inspection windows were placed to capture all cavitation phenomena. Exemplarily the cavitation phenomena and their erosive potential are to be described on the basis of high-speed sequences for selected cavitation conditions. Also the mechanism of the incipient cavitation and the opening of the self acting valves could be clearly investigated with this experimental setup. Standards and guidelines were discussed concerning the economical operating of reciprocating Positive Displacement Pumps

  • Pipeline Vibrations And Pressure Pulsations—Reasons And Solutions
    'Biophysical Society of Japan', 2011
    Co-Authors: Schlücke Eberhard
    Abstract:

    TutorialEvery pump has some kind of non-continual conveying behavior or effect. Because the conveyed liquids as well as the pipelines and support structures in the connected system are elastic, the conveyed liquid will transport these fluidmechanical or -acoustical dynamics into the connected system and can excite them to vibrations up to critical resonance situations. The consequences of these dynamics can be fatigue ruptures or not acceptable deformations at or of all connected parts or structures as well as damages. This tutorial covers all these topics, describes pump characteristics, how a system can react and what can be done to avoid pressure pulsations or vibrations in a system. Centrifugal Pumps or vane cell Pumps i.e. always generate vane passing frequencies resulting in certain pulsations while reciprocating machinery and also some rotating Positive Displacement Pumps have pulsating conveying behaviors. In connection with these behaviors also pressure shocks and water hammers can occur. Pipelines or cantilevers but also more complex structures of process plants instead behave like strings or the corpus of a guitar. They can vibrate like acoustical music instruments and therefore also can be calculated like these. When the system is simple analytical equations can be used to determine the natural frequencies. Based on this, a stable and stiff system can be designed. But when the system gets more complex only numerical methods can generate reliable results. When the natural frequencies and the vibrating behaviors are available the correct damper design or damper combination can be selected