scholarly journals Predictions of Vortex Flow in a Diesel Multi-Hole Injector Using the RANS Modelling Approach

Fluids ◽  
2021 ◽  
Vol 6 (12) ◽  
pp. 421
Author(s):  
Aishvarya Kumar ◽  
Jamshid Nouri ◽  
Ali Ghobadian
Keyword(s):  
Flow Structure ◽  
Engine Performance ◽  
Internal Flow ◽  
Vertical Axis ◽  
Field Analysis ◽  
Vortical Flow ◽  
Fuel Injector ◽  
Fuel Injectors ◽  
Performance And Emissions ◽  
Modelling Approach

The occurrence of vortices in the sac volume of automotive multi-hole fuel injectors plays an important role in the development of vortex cavitation, which directly influences the flow structure and emerging sprays that, in turn, influence the engine performance and emissions. In this study, the RANS-based turbulence modelling approach was used to predict the internal flow in a vertical axis-symmetrical multi-hole (6) diesel fuel injector under non-cavitating conditions. The project aimed to predict the aforementioned vortical structures accurately at two different needle lifts in order to form a correct opinion about their occurrence. The accuracy of the simulations was assessed by comparing the predicted mean axial velocity and RMS velocity of LDV measurements, which showed good agreement. The flow field analysis predicted a complex, 3D, vortical flow structure with the presence of different types of vortices in the sac volume and the nozzle hole. Two main types of vortex were detected: the “hole-to-hole” connecting vortex, and double “counter-rotating” vortices emerging from the needle wall and entering the injector hole facing it. Different flow patterns in the rotational direction of the “hole-to-hole” vortices have been observed at the low needle lift (anticlockwise) and full needle lift (clockwise), due to their different flow passages in the sac, causing a much higher momentum inflow at the lower lift with its much narrower flow passage.

On-Site Emissions and Fuel Consumption Measurement to Compare Locomotive Fuel Injector Performance

2006 ◽  
Author(s):  
W. Scott Wayne ◽  
Ryan A. Barnett ◽  
Jeffrey M. Cutright ◽  
Ted E. Stewart
Keyword(s):  
West Virginia ◽  
Fuel Consumption ◽  
Alternative Fuels ◽  
Engine Performance ◽  
Combustion Efficiency ◽  
Fuel Injector ◽  
West Virginia University ◽  
Test Procedures ◽  
Fuel Injectors ◽  
Locomotive Engine

As part of the Norfolk-Southern Railroad’s on-going investigation into fuel consumption reductions for their fleet of 3000 locomotives, the Center for Alternative Fuels, Engines and Emissions at West Virginia University conducted on-site locomotive engine performance and emissions measurements to characterize the performance, fuel consumption and emissions associated with fuel injectors from two injector suppliers. Emissions and fuel consumption were measured using the West Virginia University Transportable Locomotive Emissions Testing Laboratory, which was set up at the Norfolk-Southern Heavy Repair Facility in Roanoke, Virginia. The tests were conducted to evaluate potential emissions and fuel consumption differences between two fuel injector suppliers using an EMD GP38-2 locomotive equipped with a 2100 hp (1566 kW), 16-cylinder, EMD 16-645E engine. The test locomotive engine was freshly overhauled and certified to the EPA locomotive Tier 0 emissions standards. Emissions and fuel consumption measurements were conducted according to the Federal Test Procedures defined in the Code of Federal Regulations 40CFR Part 92 Subpart B [1]. The engine was first tested in the “as overhauled” configuration with the OEM fuel injectors to establish the baseline emissions and fuel consumption. The baseline FTP results confirmed that this locomotive was in compliance with the Federal Tier 0 emissions standards. The OEM specification fuel injectors were replaced with “Fuel Saver” injectors designed and manufactured by an aftermarket injector supplier referred to in this paper as Supplier B. The Supplier B injectors reduced fuel consumption on the average of 2–4% for each notch, except for Notch 4 and Low Idle. However, the Supplier B injectors increased the NOx levels by 20–30% for almost every notch, which is an expected result due to the improved combustion efficiency.

Improving the performance of a diesel engine by changing injectors characteristics after reduction on the compression ratio

2021 ◽  
Vol 15 (2) ◽  
pp. 8153-8168
Author(s):  
Saeed Chamehsara ◽  
Mohammadreza Karami
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Engine Performance ◽  
Combustion Engines ◽  
Fuel Injector ◽  
Start Time ◽  
Performance And Emissions ◽  
Nozzle Hole ◽  
The Impact

In order to repair internal combustion engines, sometimes it is necessary to replace the components of these engines with each other. Therefore changes in engine performance are inevitable in these conditions. In the present study, by changing the coneccting rod and the crank of the OM457 turbo diesel-fueled engine with the OM444, it was observed that the performance of the engine decreases. Numerical simulations have been carried out to study the Possible ways to mitigate this reduction. One way to achieve this goal is to change the fuel injector’s characteristics such as, fuel injector’s nozzle hole diameter, number of nozzle holes, and start time of fuel injection. In this study, the impact of these parameters on the performance and emissions of these engines were analyzed. Another scenario is an increase in inlet fuel and air by the same amount. The results indicate that By reducing the diameter of fuel injector holes and hole numbers, the performance of the engine was increased. on the other hand, the NOx emissions were increased while the amount of soot emission decreased. The same results were concluded by retarding the start time of injection. Subsequently, a case study of changing fuel injector parameters for mitigation of decreased performance was performed. These parameters were simultaneously applied, and results were compared. The performance of the engine with improved injector’s characteristics was close to the main OM457. Similar results were obtained by increasing the amount of inlet air and fuel.

A Comparison of Injection, Spray, and Combustion Characteristics for Non-Eroded and Eroded Multi-Hole Fuel Injectors

2021 ◽  
Author(s):  
Gina M. Magnotti ◽  
A. Cody Nunno ◽  
Prithwish Kundu ◽  
Aniket Tekawade ◽  
Brandon A. Sforzo ◽  
...  
Keyword(s):  
Engine Performance ◽  
Flow Simulation ◽  
Chemical Mechanism ◽  
Fuel Injector ◽  
Fuel Injectors ◽  
Combustion Modeling ◽  
Simulation Tools ◽  
Variable Approach ◽  
Coupling Approach ◽  
Lift Off

Abstract It is well known that cavitation erosion in fuel injectors can prevent reliable engine performance after only several thousand hours of operation. However, current simulation tools lack the ability to link flow predictions within the fuel injector to both the efficacy of combustion strategies and lifetime of the injector. Multiphase flow simulation predictions were studied and compared between an informed baseline injector geometry and an x-ray scanned eroded injector geometry. Overall, erosion was found to decrease the fuel mass delivery and injection velocities. A two-stage static coupling approach was employed to link the predicted injection conditions from non-eroded and eroded injectors with the external spray simulations under reacting conditions. Combustion modeling in this coupled approach was carried out using the Unsteady Flamelet Progress Variable approach with a detailed chemical mechanism for n-dodecane, comprising of 2,755 species and 11,173 reactions. Erosion in the injectors led to lower rates of spray penetration in comparison to the baseline configurations. Analysis of the reacting spray simulations revealed an insensitivity of ignition to erosion, yet shorter lift off lengths, higher levels of the soot, and lower levels of NOx were predicted in the eroded injector.

Experimental and Numerical Analysis of a Motorcycle Air Intake System Aerodynamics and Performance

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan
Keyword(s):  
Combustion Process ◽  
Three Dimensional ◽  
Engine Performance ◽  
Internal Flow ◽  
Rapid Expansion ◽  
Navier Stokes ◽  
Turbulent Fluctuation ◽  
Ansys Fluent ◽  
Induction System ◽  
Acceleration And Deceleration

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.

Improving diesel engine performance and emissions characteristics fuelled with biodiesel

Fuel ◽  
2021 ◽  
Vol 302 ◽  
pp. 121097
Author(s):  
M. Mourad ◽  
Khaled R.M. Mahmoud ◽  
El-Sadek H. NourEldeen
Keyword(s):  
Diesel Engine ◽  
Engine Performance ◽  
Performance And Emissions ◽  
Engine Performance And Emissions

scholarly journals Numerical Investigation of the Effect of Air Leaking into the Working Fluid on the Performance of a Steam Ejector

2021 ◽  
Vol 11 (13) ◽  
pp. 6111
Author(s):  
He Li ◽  
Xiaodong Wang ◽  
Jiuxin Ning ◽  
Pengfei Zhang ◽  
Hailong Huang
Keyword(s):  
Flow Structure ◽  
Mass Fraction ◽  
Internal Flow ◽  
Working Fluid ◽  
Physical Parameters ◽  
Entrainment Ratio ◽  
Air Mass ◽  
Steam Ejector ◽  
Primary Fluid ◽  
Mass Fractions

This paper investigated the effect of air leaking into the working fluid on the performance of a steam ejector. A simulation of the mixing of air into the primary and secondary fluids was performed using CFD. The effects of air with a 0, 0.1, 0.3 and 0.5 mass fraction on the entrainment ratio and internal flow structure of the steam ejector were studied, and the coefficient distortion rates for the entrainment ratios under these air mass fractions were calculated. The results demonstrated that the air modified the physical parameters of the working fluid, which is the main reason for changes in the entrainment ratio and internal flow structure. The calculation of the coefficient distortion rate of the entrainment ratio illustrated that the air in the primary fluid has a more significant impact on the change in the entrainment ratio than that in the secondary fluid under the same air mass fraction. Therefore, the air mass fraction in the working fluid must be minimized to acquire a precise entrainment ratio. Furthermore, this paper provided a method of inspecting air leakage in the experimental steam ejector refrigeration system.

scholarly journals Numerical simulation and experimental validation of cavitating flow in a multi-hole diesel fuel injector

2021 ◽  
pp. 146808742199863
Author(s):  
Aishvarya Kumar ◽  
Ali Ghobadian ◽  
Jamshid Nouri
Keyword(s):  
Computational Cost ◽  
Cavitating Flow ◽  
Field Analysis ◽  
Navier Stokes ◽  
Fuel Injector ◽  
Fluid Behavior ◽  
Flow Field Analysis ◽  
Charged Couple Device ◽  
Biodiesel Fuels ◽  
High Level

This study assesses the predictive capability of the ZGB (Zwart-Gerber-Belamri) cavitation model with the RANS (Reynolds Averaged Navier-Stokes), the realizable k-epsilon turbulence model, and compressibility of gas/liquid models for cavitation simulation in a multi-hole fuel injector at different cavitation numbers (CN) for diesel and biodiesel fuels. The prediction results were assessed quantitatively by comparison of predicted velocity profiles with those of measured LDV (Laser Doppler Velocimetry) data. Subsequently, predictions were assessed qualitatively by visual comparison of the predicted void fraction with experimental CCD (Charged Couple Device) recorded images. Both comparisons showed that the model could predict fluid behavior in such a condition with a high level of confidence. Additionally, flow field analysis of numerical results showed the formation of vortices in the injector sac volume. The analysis showed two main types of vortex structures formed. The first kind appeared connecting two adjacent holes and is known as “hole-to-hole” connecting vortices. The second type structure appeared as double “counter-rotating” vortices emerging from the needle wall and entering the injector hole facing it. The use of RANS proved to save significant computational cost and time in predicting the cavitating flow with good accuracy.

scholarly journals Jet A and Propane gas combustion in a turboshaft engine: performance and emissions reductions

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Ali Hasan ◽  
Oskar J. Haidn
Keyword(s):  
Combustion Process ◽  
Engine Performance ◽  
Emissions Reductions ◽  
Gas Combustion ◽  
Liquid Petroleum Gas ◽  
Performance And Emissions ◽  
Air Mixing ◽  
Turboshaft Engine ◽  
Engine Performance And Emissions ◽  
Lower Carbon

AbstractThe Paris Agreement has highlighted the need in reducing carbon emissions. Attempts in using lower carbon fuels such as Propane gas have seen limited success, mainly due to liquid petroleum gas tanks structural/size limitations. A compromised solution is presented, by combusting Jet A fuel with a small fraction of Propane gas. Propane gas with its relatively faster overall igniting time, expedites the combustion process. Computational fluid dynamics software was used to demonstrate this solution, with results validated against physical engine data. Jet A fuel was combusted with different Propane gas dosing fractions. Results demonstrated that depending on specific propane gas dosing fractions emission reductions in ppm are; NOx from 84 to 41, CO2 from less than 18,372 to less than 15,865, escaping unburned fuels dropped from 11.4 (just Jet A) to 6.26e-2 (with a 0.2 fraction of Propane gas). Soot and CO increased, this is due to current combustion chamber air mixing design.

scholarly journals A Comparison of Ethanol, Methanol, and Butanol Blending with Gasoline and Its Effect on Engine Performance and Emissions Using Engine Simulation

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1322
Author(s):  
Simeon Iliev
Keyword(s):  
Alternative Fuels ◽  
Fossil Fuels ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Engine Simulation ◽  
Engine Model ◽  
Fuel Blends ◽  
Performance And Emissions ◽  
Blended Fuels

Air pollution, especially in large cities around the world, is associated with serious problems both with people’s health and the environment. Over the past few years, there has been a particularly intensive demand for alternatives to fossil fuels, because when they are burned, substances that pollute the environment are released. In addition to the smoke from fuels burned for heating and harmful emissions that industrial installations release, the exhaust emissions of vehicles create a large share of the fossil fuel pollution. Alternative fuels, known as non-conventional and advanced fuels, are derived from resources other than fossil fuels. Because alcoholic fuels have several physical and propellant properties similar to those of gasoline, they can be considered as one of the alternative fuels. Alcoholic fuels or alcohol-blended fuels may be used in gasoline engines to reduce exhaust emissions. This study aimed to develop a gasoline engine model to predict the influence of different types of alcohol-blended fuels on performance and emissions. For the purpose of this study, the AVL Boost software was used to analyse characteristics of the gasoline engine when operating with different mixtures of ethanol, methanol, butanol, and gasoline (by volume). Results obtained from different fuel blends showed that when alcohol blends were used, brake power decreased and the brake specific fuel consumption increased compared to when using gasoline, and CO and HC concentrations decreased as the fuel blends percentage increased.

The Civic: A Concept in Vortex Induced Combustion for the Solar Gemini 10 kW Gas Turbine

1981 ◽  
Vol 103 (1) ◽  
pp. 34-42 ◽  
Author(s):  
J. R. Shekleton
Keyword(s):  
Gas Turbine ◽  
Diffusion Flames ◽  
Reynolds Numbers ◽  
Flame Stabilization ◽  
Fuel Injector ◽  
Combustion Chambers ◽  
Turbine Generator ◽  
Fuel Injectors ◽  
Swirl Flame ◽  
Combustion Processes

The Radial Engine Division of Solar Turbines International, an Operating Group of International Harvester, under contract to the U.S. Army Mobility Equipment Research & Development Command, developed and qualified a 10 kW gas turbine generator set. The very small size of the gas turbine created problems and, in the combustor, novel solutions were necessary. Differing types of fuel injectors, combustion chambers, and flame stabilizing methods were investigated. The arrangement chosen had a rotating cup fuel injector, in a can combustor, with conventional swirl flame stabilization but was devoid of the usual jet stirred recirculation. The use of centrifugal force to control combustion conferred substantial benefit (Rayleigh Instability Criteria). Three types of combustion processes were identified: stratified and unstratified charge (diffusion flames) and pre-mix. Emphasis is placed on five nondimensional groups (Richardson, Bagnold, Damko¨hler, Mach, and Reynolds numbers) for the better control of these combustion processes.

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