Analysis of a Double Inlet Gerotor Pump: A Dynamic Multi-Phase CFD Approach Accounting for the Fluid Compressibility and Temperature Dependent Properties

2019 ◽  
Author(s):  
Massimo Milani ◽  
Luca Montorsi ◽  
Stefano Terzi ◽  
Gabriele Storchi ◽  
Andrea Lucchi
Keyword(s):  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Bubble Formation ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Fluid Temperature ◽  
Gerotor Pump ◽  
Fluid Properties ◽  
Intake Pressure ◽  
Multi Phase

Abstract The paper analyzes the fluid dynamic performance of a double inlet Gerotor pump by means of a multi-phase and multicomponent CFD approach. The numerical simulation includes the full 3D geometry of the pump as well as the real physics of the compressible hydraulic fluid and the rotating dynamic motion. The aeration and cavitation phenomena are included in the analysis adopting the Rayleight-Plesset equation and inertia controlled growth model for bubble formation. Cavitation and aeration phenomena are detected, especially when intake pressure is lower than atmospheric pressure. The influence of the fluid temperature variation on the component performance is also numerically predicted. The accuracy of a detailed modelling of the fluid properties variation with respect to the temperature and pressure is addressed and the effects on the numerical results is investigated. The rotational speeds of the internal and the external gears of the pump and the engagement between the teeth are addressed by means of an overset mesh approach. Constant leak height is considered between the gears and the case, while the overset mesh approach is adopted in order to accurately predict the leakage due to the teeth engagement. This numerical approach enables to investigate the dynamic performance of Gerotor gear pumps in terms of flow rate and pressure ripples and volumetric efficiency under standard and critical (actual) operating conditions. Good agreement between numerical and experimental results was found for specific operating conditions.

The Role of Simulation in the Development of a Fast-Actuation Solenoid C.R. Injection System

2004 ◽  
Author(s):  
Gian Marco Bianchi ◽  
Piero Pelloni ◽  
Giovanni Osbat ◽  
Marco Parotto ◽  
Rita Di Gioia ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Numerical Approach ◽  
Linear Analysis ◽  
Operating Conditions ◽  
System Model ◽  
Injection System ◽  
Multiple Injection ◽  
Pressure Regulator

Upcoming Euro 4 and Euro 5 emission standards are increasing efforts on injection system developments in order to improve mixture quality and combustion efficiency. The target features of advanced injection system are related to their capability of operating multiple injection with a precise control of amount of fuel injected, low cycle-by-cycle variability and life drift, within flexible strategies. In order to accomplish this task, performance must be optimised since injection system concept development by acting on. The extensive use of numerical approach has been identified as a necessary integration to experiments in order to put on the market high quality injection system accomplishing strict engine control strategies. The modelling approach allows focusing the experimental campaign only on critical issues saving time and costs, furthermore it is possible to deeply understand inner phenomena that cannot be measured. The lump/ID model of the whole system built into the AMESim® code was presented in previous works: particular attention was devoted in the simulation of the electromagnetic circuits, actual fluid-dynamic forces acting on needle surfaces and discharge coefficients, evaluated by means 3D-CFD simulations. In order to assess new injection system dynamic response under multiple injection strategies reproducing actual engine operating conditions it is necessary to find to proper model settings. In this work the integration between the injector and the system model, which comprehends the pump, the pressure regulator, the rail and the connecting-pipes, will be presented. For reproducing the dynamic response of he whole system will be followed a step-by-step approach in order to prevent modelling inaccuracies. Firstly will be presented the linear analysis results performed in order to find injection system own natural frequencies. Secondly based on linear analysis results will be found proper injection system model settings for predicting dynamic response to external excitations, such as pump perturbations, pressure regulator dynamics and injection pulses. Thirdly experimental results in terms of instantaneous flow rate and integrated injected volume for different operating conditions will be presented in order to highlight the capability of the modelling methodology in addressing the new injection system design.

scholarly journals Pipeline Design Software and the Simulation of Liquid Propane/Butane - Light Oils Pipeline Operations

1996 ◽  
Author(s):  
John Peters
Keyword(s):  
Pressure Drop ◽  
Computer Software ◽  
Simulation Software ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Fluid Temperature ◽  
Fluid Properties ◽  
Products Pipeline ◽  
The Impact ◽  
Propane Butane

A comprehensive and integrated suite of computer software routines has been developed to simulate the flow of liquids in pipelines. The fluid properties module accommodates Newtonian and non-Newtonian liquids or mixtures including corrections for changes in properties with temperature and pressure. The hydraulic model calculates pressure drop in single or looped pipelines based on the diameter, route (length) and profile data provided. For multi-product pipelines the hydraulics module estimates energy loss for any sequence of batches given the size and fluid properties of each batch, and the velocity in the pipeline. When the characteristics of existing or proposed pipeline pumps are included, location and size of pumps can be optimized. The effect of heat loss on pressure drop is predicted by invoking the module which calculates the fluid temperature profile based on operating conditions, fluid properties, pipe and insulation conductivity and soil heat transfer data. Modules, created to simulate heater or cooler operations, can be incorporated to compensate for changes in temperature. Input data and calculated results can be presented in a format customized by the user. The simulation software has been successfully applied to multi-product, fuel oil, and non-Newtonian emulsion pipelines. The simulation and operation of a refinery products pipeline for the transportation of propane, butane, gasoline, jet and diesel batches will be discussed. The impact of high vapour pressure batches (i.e., propane and butane) on the operation of the pipeline and on the upstream and downstream facilities will be examined in detail.

scholarly journals CFD Investigations of Bath Dynamics in a Pilot-Scale TSL Furnace

2021 ◽  
Author(s):  
D. Obiso ◽  
M. Reuter ◽  
A. Richter
Keyword(s):  
Fluid Dynamics ◽  
Bubble Dynamics ◽  
Cfd Simulation ◽  
Bubble Formation ◽  
Numerical Approach ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Slag Bath ◽  
Front Tracking Method ◽  
Vof Model

AbstractThe hydrodynamics of a Top Submerged Lance (TSL) slag bath are investigated here by means of Computational Fluid Dynamics (CFD) simulation. The object of the study is the pilot-scale furnace located at TU Bergakademie Freiberg, where air is injected beneath the slag bath with a top lance. The fluid dynamics system is evaluated at operating conditions, with experimentally measured slag physical properties and real flow rates. The numerical approach is based on the Volume Of Fluid (VOF) model, a front-tracking method that allows the interface to be geometrically reconstructed. Using a fine computational grid, the multiphase interactions are calculated with a high level of detail, revealing the mechanisms of bubble formation and bath dynamics. Two lance configurations are compared, with and without a swirler, and the effect on the hydrodynamics is discussed with regards to key features of the process, such as bubble dynamics, slag splashing, the interface area, rotational sloshing, and bath mixing. The model predicts bubble frequencies in the range of 2.5 to 3 Hz and captures rotational sloshing waves with half the frequencies of the bubble detachment. These results agree with real furnace data from the literature, proving the reliability of the computing model and adding value to the empirical understanding of the process, thanks to the direct observation of the resolved multiphase flow features. The comparative study indicates that the air swirler has an overall positive effect in addition to the proposed enhancement of lance cooling, with an increase in the bath mixing and a reduction in the splashing.

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.

Health Monitoring of Centrifugal Pumps Using Digital Models

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Amr A. Abdel Fatah ◽  
Mohammed A. Hassan ◽  
Mohamed Lotfy ◽  
Antoine S. Dimitri
Keyword(s):  
Centrifugal Pump ◽  
Fluid Dynamic ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Normal Operation ◽  
Centrifugal Pumps ◽  
Digital Models ◽  
Exciting Forces

The area of predictive maintenance (PM) has received growing research interest in the past few years. Diagnostic capabilities of PM technologies have increased due to advances made in sensor technologies, signal processing algorithms, and the rapid development of computational power and data handling algorithms. Conventional PM programs are mostly built around analyzing sensors' data collected from physical systems. Incorporating simulation data collected from digital models replicating the physical system with sensors' data can lead to more optimization for operation and maintenance. This paper demonstrates the role of using digital models in implementing effective condition monitoring on centrifugal pumps. Two digital models are used to study the dynamic performance of a centrifugal pump experiencing cavitation condition. The first model is a three-dimensional fully turbulent computational fluid dynamic (CFD) model. Based on the pressure distribution obtained from the CFD, a novel analytical pressure pulsation model is developed and used to simulate the exciting forces affecting the pump. The second digital model is a pump casing dynamic model which is used to predict the casing vibration response to exciting forces due to faulty operating conditions. Results obtained from the digital models are validated using an experimental test rig of a small centrifugal pump. Using this concept, a pump faulty operation can be simulated to provide complete understanding of the root cause of the fault. Additionally, digital models can be used to simulate different corrective actions that would restore the normal operation of the pump.

Numerical Modelling of the Cooling System at ALBA Synchrotron Radiation Facility to Understand its Performance

2017 ◽  
Author(s):  
Xavier Escaler ◽  
Montserrat Prieto ◽  
Marcos Quispe ◽  
Morten Kjeldsen ◽  
Oscar De La Torre
Keyword(s):  
Cooling System ◽  
Fluid Dynamic ◽  
Flow Distribution ◽  
Optimal Operation ◽  
Operating Conditions ◽  
System Response ◽  
Fluid Temperature ◽  
Current Design ◽  
Control Fluid ◽  
Air Pockets

The ALBA Synchrotron Light Source in Barcelona (Spain) requires a reliable, stable and adequate cooling system for its optimal operation. The current design with four long and intricate consumption lines with a ring type piping layout (270 m perimeter) and a common return pipe is believed to compromise the operability and to promote the trapping of air pockets. In order to improve its performance, a better understanding of the thermo-fluid dynamic behaviour is required that permits to opmitize the system and to anticipate unexpected failures. For that, a detailed 1D model has been built with Flowmaster® software comprising all the components and the various regulation mechanisms to control fluid temperature and pressure. Preliminarily, the model has been validated in steady state operating conditions against experimental measurements showing good agreement. Then, a series of specific steady and transient numerical simulations have been carried out to determine the system response. In particular, the effects of blockage and leakage as well as the increase or decrease of heat duty have been analysed. Furthermore, the best flow distribution through the rings has also been found to reduce the air content by maximizing the velocities.

Power Test System Development and Dynamic Performance State Estimation Based on Hub Motor Vehicle

2020 ◽  
Vol 13 (2) ◽  
pp. 126-140
Author(s):  
Jing Gan ◽  
Xiaobin Fan ◽  
Zeng Song ◽  
Mingyue Zhang ◽  
Bin Zhao
Keyword(s):  
Real Time ◽  
Dynamic Performance ◽  
Test System ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Maximum Speed ◽  
Performance Parameters ◽  
Power Performance ◽  
Power Test ◽  
The Real

Background: The power performance of an electric vehicle is the basic parameter. Traditional test equipment, such as the expensive chassis dynamometer, not only increases the cost of testing but also makes it impossible to measure all the performance parameters of an electric vehicle. Objective: A set of convenient, efficient and sensitive power measurement system for electric vehicles is developed to obtain the real-time power changes of hub-motor vehicles under various operating conditions, and the dynamic performance parameters of hub-motor vehicles are obtained through the system. Methods: Firstly, a set of on-board power test system is developed by using virtual instrument (Lab- VIEW). This test system can obtain the power changes of hub-motor vehicles under various operating conditions in real-time and save data in real-time. Then, the driving resistance of hub-motor vehicles is analyzed, and the power performance of hub-motor vehicles is studied in depth. The power testing system is proposed to test the input power of both ends of the driving motor, and the chassis dynamometer is combined to test so that the output efficiency of the driving motor can be easily obtained without disassembly. Finally, this method is used to carry out the road test and obtain the vehicle dynamic performance parameters. Results: The real-time current, voltage and power, maximum power, acceleration time and maximum speed of the vehicle can be obtained accurately by using the power test system in the real road experiment. Conclusion: The maximum power required by the two motors reaches about 9KW, and it takes about 20 seconds to reach the maximum speed. The total power required to maintain the maximum speed is about 7.8kw, and the maximum speed is 62km/h. In this article, various patents have been discussed.

scholarly journals Experimental performance comparison between circular and elliptical tubes in evaporative condensers

2021 ◽  
Author(s):  
Giuseppe Starace ◽  
Lorenzo Falcicchia ◽  
Pierpaolo Panico ◽  
Maria Fiorentino ◽  
Gianpiero Colangelo
Keyword(s):  
Heat Transfer ◽  
Experimental Approach ◽  
Fluid Dynamic ◽  
Major Axis ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Condensation Temperature ◽  
Air Cooled Condensers ◽  
Reduced Scale ◽  
Dynamic Phenomena

AbstractIn refrigeration systems, evaporative condensers have two main advantages compared to other condensation heat exchangers: They operate at lower condensation temperature than traditional air-cooled condensers and require a lower quantity of water and pumping power compared to evaporative towers. The heat and mass transfer that occur on tube batteries are difficult to study. The aim of this work is to apply an experimental approach to investigate the performance of an evaporative condenser on a reduced scale by means of a test bench, consisting of a transparent duct with a rectangular test section in which electric heaters, inside elliptical pipes (major axis 32 mm, minor axis 23 mm), simulate the presence of the refrigerant during condensation. By keeping the water conditions fixed and constant, the operating conditions of the air and the inclination of the heat transfer geometry were varied, and this allowed to carry out a sensitivity analysis, depending on some of the main parameters that influence the thermo-fluid dynamic phenomena, as well as a performance comparison. The results showed that the heat transfer increases with the tube surface exposed directly to the air as a result of the increase in their inclination, that has been varied in the range 0–20°. For the investigated conditions, the average increase, resulting by the inclination, is 28%.

scholarly journals Experimental Investigation and Comparison of the Thermal Performance of Additively and Conventionally Manufactured Heat Exchangers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 574
Author(s):  
Ana Vafadar ◽  
Ferdinando Guzzomi ◽  
Kevin Hayward
Keyword(s):  
Surface Roughness ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Experimental Studies ◽  
Manufacturing Method ◽  
Industrial Sectors

Air heat exchangers (HXs) are applicable in many industrial sectors because they offer a simple, reliable, and cost-effective cooling system. Additive manufacturing (AM) systems have significant potential in the construction of high-efficiency, lightweight HXs; however, HXs still mainly rely on conventional manufacturing (CM) systems such as milling, and brazing. This is due to the fact that little is known regarding the effects of AM on the performance of AM fabricated HXs. In this research, three air HXs comprising of a single fin fabricated from stainless steel 316 L using AM and CM methods—i.e., the HXs were fabricated by both direct metal printing and milling. To evaluate the fabricated HXs, microstructure images of the HXs were investigated, and the surface roughness of the samples was measured. Furthermore, an experimental test rig was designed and manufactured to conduct the experimental studies, and the thermal performance was investigated using four characteristics: heat transfer coefficient, Nusselt number, thermal fluid dynamic performance, and friction factor. The results showed that the manufacturing method has a considerable effect on the HX thermal performance. Furthermore, the surface roughness and distribution, and quantity of internal voids, which might be created during and after the printing process, affect the performance of HXs.

scholarly journals A theoretical and numerical approach for selecting miniaturized antenna topologies on magneto-dielectric substrates

2015 ◽  
Vol 7 (3-4) ◽  
pp. 369-377 ◽  
Author(s):  
Alex Pacini ◽  
Alessandra Costanzo ◽  
Diego Masotti
Keyword(s):  
Near Field ◽  
Dielectric Materials ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Microwave Range ◽  
Dielectric Substrates ◽  
Full Wave ◽  
Miniaturized Antenna ◽  
Wavelength Radiation ◽  
Definition Of

An increasing interest is arising in developing miniaturized antennas in the microwave range. However, even when the adopted antennas dimensions are small compared with the wavelength, radiation performances have to be preserved to keep the system-operating conditions. For this purpose, magneto-dielectric materials are currently exploited as promising substrates, which allows us to reduce antenna dimensions by exploiting both relative permittivity and permeability. In this paper, we address generic antennas in resonant conditions and we develop a general theoretical approach, not based on simplified equivalent models, to establish topologies most suitable for exploiting high permeability and/or high-permittivity substrates, for miniaturization purposes. A novel definition of the region pertaining to the antenna near-field and of the associated field strength is proposed. It is then showed that radiation efficiency and bandwidth can be preserved only by a selected combinations of antenna topologies and substrate characteristics. Indeed, by the proposed independent approach, we confirm that non-dispersive magneto-dielectric materials with relative permeability greater than unit, can be efficiently adopted only by antennas that are mainly represented by equivalent magnetic sources. Conversely, if equivalent electric sources are involved, the antenna performances are significantly degraded. The theoretical results are validated by full-wave numerical simulations of reference topologies.

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