scholarly journals A Numerical Analysis of an Innovative Flow Ripple Reduction Method for External Gear Pumps

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 471
Author(s):  
Gianluca Marinaro ◽  
Emma Frosina ◽  
Adolfo Senatore

In this paper, an innovative solution to minimize noise emission, acting on the flow ripple, in a prototype External Gear Pump (EGP) is presented. Firstly, a new tool capable to completely simulate this pump’s typologies, called EgeMATor, is presented; the hydraulic model, adopted for the simulation, is based on a lumped parameter method using a control volume approach. Starting from the pump drawing, thanks to different subroutines developed in different environments interconnected, it is possible to analyze an EGP. Results have been compared with the outputs of a three-dimensional CFD numerical model built up using a commercial code, already used with success by the authors. In the second section, an innovative solution to reduce the flow ripple is implemented. This technology is called Alternative Capacitive Volumes (ACV) and works by controlling and uniformizing the reverse flow, performing a consistent reduction of flow non-uniformity amplitude. In particular, a high reduction of the flow non-uniformity is notable in the frequency domain on the second fundamental frequency. The technology is easy to accommodate in a pump housing, especially for high-pressure components, and it helps with reducing the fluid-borne noise.

Author(s):  
Hai-Lin Zhu ◽  
Peng Ning ◽  
Min Zou ◽  
Xingpei Qin ◽  
Jun Pan

Aimed at solving the problems of radial fluid pressure imbalance, bigger flow ripple and shorter service life that exists in traditional gear pumps, a new type of gear pump based on the principle of harmonic gear drive is put forth, where the function for pumping fluid is achieved by mutual engagement between flexible gear and rigid gear. The structural composition, principle and features of the new gear pump are described in this article. The new pump has two higher pressure cavities arranged symmetrically, which counteracts the fluid pressure and the pump could work longer. Its displacement is two times that of the conventional gear pump and the total discharge is bigger. Flow pulsation, vibration and noise in the new pump are evidently diminished, which make the operation smooth. The new gear pump has superiority in performance and could guide the development in gear pump technology.


2012 ◽  
Vol 591-593 ◽  
pp. 2139-2142
Author(s):  
Hong Ding

Gear pump is the most commonly used hydraulic component in hydraulic drive system.Volumetric efficiency of the traditional gear pump is low, big flow ripple causes large pressure fluctuations, makes pipes and valves vibration, noisy. The imbalance pressure on gear pump’s gears, shafts and bearings and the large radial load limits its pressure increased. Planetary gear transmission compared with ordinary gear transmission, it has many unique advantages. So the writer on the basis of the combination of proposed non-circular planetary gear pumps and gear pump works discussed the structure and working principle of the pump. The non-circular planetary gear pump with many advantages such as big flow, uniform flow, low noise and so on. It can be widely used in various hydraulic transmission systems.


2011 ◽  
Vol 236-238 ◽  
pp. 2327-2331
Author(s):  
Yan Zhi Li ◽  
Li Huan Gao ◽  
Xiao Yang Tang

In this paper, the theoretical flow ripple of an external gear pump is studied for pumps of similar size using different numbers of teeth on the driving and driven gears. External gear pumps with three different types of tooth profiles are studied. Nondimensional flowrates and fluctuation coefficients of gear pumps are discussed. By using the formula, flowrates can be calculated accurately and efficiently. Results indicate that: in the case of the same displacement (except teeth number and tooth width, other parameters of the gear pump are the same) the gear pump flow pulsation decreases with the increasing of the teeth number. We also concluded that changing tooth profiles on the driving and driven gear can get different pulse amplitude of the flow ripple.


Author(s):  
Florin Iancu ◽  
Janusz Piechna ◽  
Norbert Mu¨ller

It has been shown that the wave rotor technology has the potential of improving the performance of gas turbine cycles. Moreover the radial wave rotor is an additional innovation for this technology. Unlike the commercialized axial-flow wave rotor (Comprex®), a radial one has the benefit of using centrifugal forces to improve the compression process or flow scavenging. The geometry of the rotor is much simpler and is ideal for microfabrication, which is relying mainly on two-dimensional processes to create three-dimensional features. This paper is presenting several radial ultra-micro wave rotors (UμWR) configurations and numerical analysis of these rotors. In a radial placement, the wave rotor has four possible configurations: two - general configuration, through-flow and reverse-flow, and each of these could have the low pressure air port positioned at inside or outside of the rotor. Results have been obtained using FLUENT, a Computational Fluid Dynamics (CFD) commercial code. The vast information about the unsteady processes occurring during simulation is visualized.


2003 ◽  
Vol 125 (3) ◽  
pp. 396-404 ◽  
Author(s):  
Noah D. Manring ◽  
Suresh B. Kasaragadda

In this paper, the theoretical flow ripple of an external gear pump is studied for pumps of similar size using different numbers of teeth on the driving and driven gears. In this work, the flow ripple equation is derived based upon the flow of incompressible fluid across the changing boundaries of a control volume. From this method, it is shown that the instantaneous length of action within the gear mesh determines the instantaneous flow ripple. A numerical and a closed-form approximation are presented for the instantaneous length of action and it is shown that the difference between these two solutions is negligible. Fast Fourier transform analysis is employed for identifying the harmonic frequencies and amplitudes of the flow pulse and these results are compared for 16 different pump designs. In summary, the results of this study show that the driving gear dictates the flow ripple characteristics of the pump while the driven gear dictates the pump size. As a result, it may be advantageous to design an external gear pump with a large number of teeth on the driving gear and a fewer number of teeth on the driven gear. This design configuration will tend to reduce both the physical pump size (without reducing the volumetric displacement of the pump) and the amplitude of the flow pulsation, while increasing the natural harmonic frequencies of the machine.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 342
Author(s):  
Alessandro Corvaglia ◽  
Massimo Rundo ◽  
Paolo Casoli ◽  
Antonio Lettini

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.


Author(s):  
Alessandro Corvaglia ◽  
Alessandro Ferrari ◽  
Massimo Rundo ◽  
Oscar Vento

A three-dimensional model of an external gear pump and a new application of an algorithm for the measurement of the unsteady flow rate in hydraulic pipes are presented. The experimental delivery flow ripple was compared with the outcomes of a simulation under different operating conditions. A comprehensive computational fluid dynamics model of the pump and of the high-pressure delivery circuit was developed in SimericsMP+®. The pump model considers the clearances, which vary according to the shaft angle, between the tip of the tooth and the inner surface of the stator, as well as between the flanks of the teeth that are in contact. The pump delivery circuit is constituted by a straight pipe with a fixed orifice at the end to generate the load. The model of the entire system was preliminarily validated in terms of delivery pressure ripple. Subsequently, the simulated flow ripple was contrasted with the instantaneous flow rate, measured by means of an innovative flow meter. It was found that the proposed flow meter is reliable in assessing the flow oscillations under the various working conditions.


2015 ◽  
Vol 760 ◽  
pp. 607-612
Author(s):  
Constantin Gheorghe OPRAN ◽  
Mircea Pricop ◽  
Constantin Teodoru

This paper present the results of the researches regarding innovative design of polymeric systems used in manufacturing of gear pumps with application to reversible pumps used both as pumps as well as motors or steps of the flow dividers. It shows the description of reversible gear pump, with compensating seal in the innovative variant and compensation sealing system for reversible pumps – innovative design. For this innovative solution has been developed a system of compensation sealing kit for reversible pumps – innovative design. In order to obtain these products was necessary to make molds for vulcanization and injection molding tools for polymeric products having special construction considering the size and special profile products. They highlight the competitive advantages of innovative compensation sealing system made by polymeric products. The paper also shows numerical analysis of the fluid at gear pumps using innovative compensation sealing proving the correctness and the advantages of new variants of sealing. The performances reversible pump that uses innovative new sealing system are homogeneous and high levels of performance than those with seals in the classic system.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2501
Author(s):  
Thomas Lobsinger ◽  
Timm Hieronymus ◽  
Hubert Schwarze ◽  
Gunther Brenner

The efficiency requirements for hydraulic pumps applied in automatic transmissions in future generations of automobiles will increase continuously. In addition, the pumps must be able to cope with multiphase flows to a certain extent. Given this background, a balanced vane pump (BVP), an internal gear pump (IGP) and a three-dimensional geared tumbling multi chamber (TMC) pump are analyzed and compared by a computational fluid dynamics (CFD) approach with ANSYS CFX and TwinMesh. Furthermore, test bench measurements are conducted to obtain experimental data to validate the numerical results. The obtained numerical results show a reasonable agreement with the experimental data. In the first CFD setup, the conveying characteristics of the pumps with pure oil regarding volumetric efficiencies, cavitation onset and pressure ripple are compared. Both the IGP and the BVP show high volumetric efficiencies and low pressure ripples whereas the TMC shows a weaker performance regarding these objectives. In the second CFD setup, an oil-bubbly air multiphase flow with different inlet volume fractions (IGVF) is investigated. It can be shown that free air changes the pumping characteristics significantly by increasing pressure and mass flow ripple and diminishing the volumetric efficiency as well as the required driving torque. The compression ratios of the pumps appear to be an important parameter that determines how the multiphase flow is handled regarding pressure and mass flow ripple. Overall, the BVP and the IGP show both a similar strong performance with and without free air. In the current development state, the TMC pump shows an inferior performance because of its lower compression ratio and therefore needs further optimization.


Author(s):  
Shivakumar Ulaganathan ◽  
Ch. Kanna Babu ◽  
Girish Kalyanrao Degaonkar

External gear pumps are typically used in aero-engines for the fuel and lubrication system due to its simplicity in construction. The design of the gear pump has been considerably improved over several years by including design features to improve its overall performance and reliability. In this paper, three-dimensional numerical analysis of an external gear was carried out by including design features such as scallops at the inlet and outlet, radial and axial clearances, journal bearing clearances and the axial tilt of the supporting bushes. The Immersed Solid Method (ISM) is used to analyze the gear pump at different operating conditions. The applicability of different turbulence models to the Immersed solid method is discussed. The internal flow features are discussed and compared with the results available in the literature. The Pump characteristics curve developed from the numerical analysis using the Immersed solid method (ISM) is compared with the experimental test results.


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