Methodology for the Evaluation of Gear Pump Performance

2020 ◽  
Author(s):  
Logan T. Williams
Keyword(s):  
Empirical Data ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Fluid Viscosity ◽  
Gear Pump ◽  
Pump Performance ◽  
Pump Speed ◽  
Multiple Parameters ◽  
Gear Pumps

Abstract Currently, most performance curves of gear pumps present volumetric efficiency as a function of one or more operating conditions. However, the nature of gear pumps is that volumetric efficiency is dependent on pump speed, pump pressure rise, and fluid viscosity. This dependency on multiple parameters impedes direct comparisons between pumps tested at disparate operating conditions or on different testbeds. A new method has been developed that formulates the volumetric efficiency as a function of a single parameter that captures pump speed, pressure, and fluid viscosity. The characteristics of the pump is then captured by curve fitting two constants to empirical data. This method allows extrapolation of pump performance beyond empirical data and direct comparison of the volumetric efficiency curves of two pumps tested under disparate conditions within a single plot. This work describes the analytical derivation of the methodology and the empirical data used for validations. Additionally, several possible applications of this method are presented.

Friction torque characteristics of an internal gear pump

2011 ◽  
Vol 225 (6) ◽  
pp. 1523-1534 ◽  
Author(s):  
Y Inaguma
Keyword(s):  
Mathematical Model ◽  
Friction Torque ◽  
Operating Conditions ◽  
Gear Pump ◽  
Operating Pressure ◽  
New Model ◽  
Pump Speed ◽  
Gear Pumps ◽  
Internal Gear ◽  
Three Components

This paper describes the influence of pump operating conditions, such as operating pressures, pump speeds, and oil temperatures, on the friction torque characteristics of internal gear pumps for automobiles. Additionally, it presents a new mathematical model reflecting the influence of the oil temperature on the friction torque. In an internal gear pump, the friction torque was affected by oil temperature as well as operating pressure and pump speed. When the operating pressure was high, the influence of oil temperature on friction torque at a pump speed of less than 1000 r/min was contrary to that at a pump speed of greater than 1000 r/min. It was considered that the friction torque is fundamentally composed of three components: the component dependent on the operating pressure, dependent on the pump speed, and independent of both the operating pressure and the pump speed. However, the component dependent on the operating pressure was affected significantly by not only the pump speed but also the oil temperature. In addition, another factor besides the viscosity of the oil existed in the component dependent on the pump speed. A mathematical model for the friction torque characteristic of the internal gear pump was newly established by adding factors including the oil temperature to the Wilson’s model. The new model was able to represent with accuracy the experimental friction torque characteristic in the internal gear pump under various pump operating conditions.

scholarly journals Effects of Working Fluids on the Performance of a Roots Pump for Hydrogen Recirculation in a PEM Fuel Cell System

2020 ◽  
Vol 10 (22) ◽  
pp. 8069
Author(s):  
Jianmei Feng ◽  
Linfen Xing ◽  
Bingqi Wang ◽  
Huan Wei ◽  
Ziyi Xing
Keyword(s):  
Water Vapor ◽  
Fuel Cell ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Fuel Cell System ◽  
Working Fluids ◽  
Pump Performance ◽  
Isentropic Efficiency

In this paper, the performance of a Roots pump for hydrogen recirculation in proton exchange membrane (PEM) fuel cell system is simulated based on CFD modeling. The Roots pump is in a three-lobe configuration with helical rotors, and it is developed specifically for fuel cell systems between 60 to 110 kW. A three-dimensional model of the Roots pump is established to predict the pump performance, including the flow rate and power consumption under various operating conditions. Extensive simulations were conducted and then verified experimentally by operating with working fluids of air and helium. Based on the validated CFD model, the contents of water vapor and nitrogen in the hydrogen recirculated are taken into account to evaluate the Roots pump performance numerically according to the actual conditions of the recirculating hydrogen at the stack outlet. It is shown that the volumetric efficiency and isentropic efficiency are improved with the increase fraction of water vapor and nitrogen. It is found that the performance of the Roots pump integrated in the PEM fuel cell system is between the performance of the pump working with air and helium. Finally, correlations of volumetric efficiency and isentropic efficiency are given based on the CFD results to show the general pattern of this kind of hydrogen pump. It is believed that these equations are very helpful to the design and operation control of the PEM fuel cell system.

Investigation on an Oil Aeration Measurement Technique for the Study of Pump Performance in an Aircraft Engine Lubrication System

2015 ◽  
Author(s):  
Laurent Ippoliti ◽  
Johan Steimes ◽  
Patrick Hendrick
Keyword(s):  
Measurement Technique ◽  
Rotational Speed ◽  
Test Bench ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Inlet Pressure ◽  
Lubrication System ◽  
Feed Pump ◽  
Pump Performance

Previous studies on feed pump performance conducted on the ULB-ATM lubrication system test bench showed the dependence of cavitation and volumetric efficiency with inlet pressure, rotational speed and aeration. This paper presents a technique of aeration measurement applied on the test bench. After a description of the device and a theoretical review of the aeration, the paper shows that the method has been tested with success. The paper illustrates it with a series of tests showing the level of aeration obtained in different operating conditions and a comparison with a pump characteristic measured on the bench.

scholarly journals The Influence of Radial and Axial Gaps on Volumetric Efficiency of External Gear Pumps

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4468
Author(s):  
Paulina Szwemin ◽  
Wieslaw Fiebig
Keyword(s):  
Fluid Flow ◽  
Volumetric Efficiency ◽  
Operating Parameters ◽  
Gear Pump ◽  
Cfd Model ◽  
External Gear Pumps ◽  
Flow Phenomena ◽  
Gear Pumps ◽  
The Impact ◽  
External Gear Pump

The design of gear pumps and motors is focused on more efficient units which are possible to achieve using advanced numerical simulation techniques. The flow that appears inside the gear pump is very complex, despite the simple design of the pump itself. The identification of fluid flow phenomena in areas inside the pump, considering the entire range of operating parameters, is a major challenge. This paper presents the results of simulation studies of leakages in axial and radial gaps in an external gear pump carried out for different gap shapes and sizes, as well as various operating parameters. To investigate the processes that affect pump efficiency and visualize the fluid flow phenomena during the pump’s operation, a CFD model was built. It allows for a detailed analysis of the impact of the gears’ eccentricity on leakages and pressure build-up on the circumference. Performed simulations made it possible to indicate the relationship between leakages resulting from the axial and radial gap, which has not been presented so far. To verify the CFD model, experimental investigations on the volumetric efficiency of the external gear pump were carried out. Good convergence of results was obtained; therefore, the presented CFD model is a universal tool in the study of flow inside external gear pumps.

scholarly journals About the Influence of Eco-Friendly Fluids on the Performance of an External Gear Pump

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 799
Author(s):  
Gabriele Muzzioli ◽  
Luca Montorsi ◽  
Andrea Polito ◽  
Andrea Lucchi ◽  
Alessandro Sassi ◽  
...  
Keyword(s):  
Olive Oil ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Volumetric Efficiency ◽  
Green Economy ◽  
Gear Pump ◽  
Research Activity ◽  
Industrial Oil ◽  
Fluid Properties ◽  
Gear Pumps

This paper wants to investigate the effects of eco-friendly fluids on the thermo-fluid-dynamic performance of external gear pumps in order to provide a first response to the increasingly urgent demands of the green economy. A computational fluid dynamics (CFD) approach based on the overset mesh technique was developed for the simulation of the full 3D geometry of an industrial pump, including all the characteristic leakages between components. A sensibility analysis of the numerical model with respect to different fluid properties was performed on a commonly used mineral oil, showing the key role of the fluid compressibility on the prediction of the pump volumetric efficiency. Moreover, the influence of temperature internal variations on both fluid density and viscosity were included. The BIOHYDRAN TMP 46 eco-friendly industrial oil and olive oil were further considered in this work, and the results of the simulations were compared for the three fluid configurations. A slightly lower volumetric efficiency was derived for the olive oil application against the other two conditions, but suggestive improvements were produced in terms of pressure and temperature distributions. Therefore, based on the obtained results, this paper encourages research activity towards the use of eco-friendly fluids in the hydraulic field.

Experimental Performance Evaluation of a Centrifugal Pump With Different Impeller Vane Geometries

2014 ◽  
Author(s):  
Susanta K. Das
Keyword(s):  
Centrifugal Pump ◽  
Computer Control ◽  
Operating Conditions ◽  
Design Parameters ◽  
Physical Parameters ◽  
Pump Efficiency ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
Pump Speed ◽  
Geometry Effects

Centrifugal pumps vane geometry plays an important role in pump’s overall performance. Thus, to know the impeller vane geometry effects on the performance of a centrifugal pump are essential from pump’s design point of view. In this study, an experimental investigation is carried out to judge the impeller vane geometry effects on the performance of a centrifugal pump. The performance of three different impeller vane geometries is evaluated in this investigation. To acquire pump performance and characteristics curves, inlet and outlet valves were manually adjusted and the pump’s rpm were varied remotely through computer control. The pressure data were obtained via installed flow rotameter for different flow rates with constant pump speed – 1800 rpm. Experimental data were used to calculate different physical parameters, such as the pump head, water horsepower — the power added to the fluid, power input to the pump–brake horse power, and pump efficiency for each of impeller vane geometries. The pump’s performance curves and the system curves were then plotted for each of the vane geometries. The results show that the pump performance as well as efficiency varies significantly for each of the impeller vane geometries. The results help to understand how to determine appropriate operating conditions and design parameters for different impeller vane geometries for obtaining optimized pump performance.

A Numerical Procedure to Design the Optimal Axial Balance of Pressure Compensated Gear Machines

2014 ◽  
Author(s):  
Divya Thiagarajan ◽  
Andrea Vacca
Keyword(s):  
Numerical Procedure ◽  
Operating Conditions ◽  
Force Balance ◽  
Gear Pump ◽  
Power Losses ◽  
Outlet Port ◽  
External Gear Pumps ◽  
Gear Pumps ◽  
Force Components ◽  
External Gear Pump

This paper presents an innovative numerical procedure to determine the optimal balancing area of lateral bushes in external gear pumps or motors. In pressure compensated designs of external gear machines, the lateral bushes perform the important functions of sealing the tooth space volumes while they transfer fluid from the inlet to the outlet port. In normal operating conditions, a lubricating gap exists between the lateral bush and the gear permitting to minimize losses due to shear stress and leakage. These conditions are found by determining proper balancing areas at the side of the bushes not facing the gears, in which the pressure of the high pressure port is properly established. This problem is also known as “axial balance” of external gear machines. To determine the optimal axial balance which minimizes the power losses associated with the lubricating gap in all operating conditions, all the static and hydrodynamic forces acting on the lateral bushes have to be considered. This delicate aspect of external gear units design is usually addressed through empirical procedures; while in this paper an automatic numerical procedure is presented. The proposed method is based on the solution of the force balance of the lateral bushes, taking into account all force components, including the hydrodynamic terms due to the relative inclination between bushes and gears and material deformation. After detailing the procedure, the paper describes its potentials by showing the advantages arising from the optimization of the axial balance of a particular external gear pump for fluid power applications.

scholarly journals Evaluation of Tooth Space Pressure and Incomplete Filling in External Gear Pumps by Means of Three-Dimensional CFD Simulations

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 342
Author(s):  
Alessandro Corvaglia ◽  
Massimo Rundo ◽  
Paolo Casoli ◽  
Antonio Lettini
Keyword(s):  
Three Dimensional ◽  
Operating Conditions ◽  
Dynamics Simulation ◽  
Inlet Pressure ◽  
Gear Pump ◽  
External Gear Pumps ◽  
Internal Fluid ◽  
Incomplete Filling ◽  
Gear Pumps ◽  
High Dynamics

The paper presents the computational fluid dynamics simulation of an external gear pump for fluid power applications. The aim of the study is to test the capability of the model to evaluate the pressure in a tooth space for the entire shaft revolution and the minimum inlet pressure for the complete filling. The model takes into account the internal fluid leakages and two different configurations of the thrust plates have been considered. The simulations in different operating conditions have been validated with proper high dynamics transducers measuring the internal pressure in a tooth space for the entire shaft revolution. Steady-state simulations have been also performed in order to detect the fall of the flow rate due to the incomplete filling of the tooth spaces when the inlet pressure is reduced. It has been demonstrated that, despite the need of a compromise for overcoming the limitation of considering fixed positions of the gears’ axes and of the thrust plates, significant results can be obtained, making the CFD approach very suitable for such analyses.

Performance and Development of a Miniature Rotary Shaft Pump (RSP)

2004 ◽  
Author(s):  
Daniel B. Blanchard ◽  
Phillip M. Ligrani ◽  
Bruce K. Gale
Keyword(s):  
Flow Rate ◽  
Pressure Rise ◽  
Electronics Cooling ◽  
Maximum Flow ◽  
Operating Conditions ◽  
Working Fluid ◽  
Pump Performance ◽  
Potential Applications ◽  
Total Analysis ◽  
And Performance

The development and performance of a novel miniature pump called the rotary shaft pump (RSP) is described. The impeller is made by boring a hole in one end of a shaft, and cutting slots in the side of the shaft at the bottom of the bored hole, such that the metal between the slots defines the impeller blades. Several impeller designs are tested over a range of operating conditions. Pump performance characteristics, including pressure rise, efficiency, slip factor, and flow rate are presented for several different pump configurations, with maximum flow rate and pressure rise of 64.9ml/min, and 2.1kPa, respectively, when the working fluid is water. Potential applications include transport of biomedical fluids, drug delivery, total analysis systems, and electronics cooling.

Evaluation of Effect of Viscosity on an Electrical Submersible Pump

2017 ◽  
Author(s):  
Gerald Morrison ◽  
Wenjie Yin ◽  
Rahul Agarwal ◽  
Abhay Patil
Keyword(s):  
Oil And Gas ◽  
Flow Behavior ◽  
Operating Conditions ◽  
Flow Coefficient ◽  
Fluid Viscosity ◽  
Submersible Pump ◽  
Viscosity Change ◽  
Pump Design ◽  
Pump Performance ◽  
Electrical Submersible Pump

Understanding and predicting the effect of viscosity change on an Electrical Submersible Pump (ESP) performance is of great significance to the oil and gas operators. The purpose of this research is to investigate the flow behavior inside a mixed flow type pump operating with fluids of different viscosities using Computational Fluid Dynamics (CFD) with the goal to establish additional terms for the pump affinity laws to scale pump performance including the effects of viscosity. Several sets of fluids of different viscosities and densities are simulated under various operating conditions. The effect of viscosity on the performance of the impeller and diffuser is discussed. Changes in the pump performance due to fluid viscosity are characterized using the dimensionless flow coefficient, head coefficient and rotational Reynolds number. The result, which can be regarded as the modified pump affinity laws for viscosity flows, was obtained based on the relationships between dimensionless coefficients. The modified affinity laws agreed well with the CFD results. Further study was conducted to validate the relationships using previously published test data for a semi axial pump design (Specific Speed, Ns: 3869) tested with fluid viscosity ranging from 1 cp to 1020 cp and in-house testing of a split vane impeller pump (Ns: 3027) and a helicoaxial pump (Ns: 5281) using 1cp and 5 cp viscosity fluid. The modified affinity laws accurately models the performance dependence upon viscosity. As with the standard affinity laws, a pump’s functional relationship varies with each pump design. Yet the modified affinity laws produce a single common curve for all operating conditions and viscosities for a specific pump.

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