Numerical investigation of the effect of injection strategy on a high-pressure isobaric combustion engine

High-pressure isobaric combustion adopted in the double compression expansion engine (DCEE) has the prospect to achieve higher thermal efficiency compared to conventional diesel combustion. This work numerically explored the effects of various injection strategies on the combustion and emission characteristics of isobaric combustion. The study developed a mathematical model to predict the injection rate profile. After validations, extensive simulations were conducted with a peak pressure of up to 300 bar – mimicking the high-pressure unit of DCEE. Several major engine design parameters such as the exhaust recirculation gas (EGR) rate, engine speed, injection strategy, and intake pressure were varied and evaluated. The results demonstrated that a higher EGR rate resulted in a higher exhaust loss but a lower heat transfer loss owing to the lower combustion temperature, so the thermal efficiency exhibited a firstly growing and then declining trend. Besides, a higher engine speed generated a higher thermal efficiency due to the shorter combustion duration and thus lower heat transfer loss. Consequently, a peak thermal efficiency of 47.5% was achieved at EGR = 50% and 1800 rpm. The high-pressure cylinder performance can also be improved with an appropriate introduction of the isochoric combustion, but its impact on the whole DCEE setup needs further investigation.

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Effect Of The Engine Speed And Loading On The Heat Transfer Within Exhaust Valves

E3S Web of Conferences ◽

10.1051/e3sconf/201912801001 ◽

2019 ◽

Vol 128 ◽

pp. 01001

Author(s):

Mahfoudh Cerdoun ◽

Bouziane Farsaoui ◽

Smail Khalfallah ◽

Rafik Lankri ◽

Carlo Carcasci

Keyword(s):

Heat Transfer ◽

Boundary Condition ◽

Engine Speed ◽

Combustion Engine ◽

Adiabatic Wall ◽

Fem Model ◽

Average Value ◽

Partial Load ◽

Two Parameters ◽

Exhaust Valves

The aim of the present paper is to investigate numerically the heat transfer within exhaust valves by considering the actual boundary conditions provided from an internal combustion engine at differentload and speed. For this purpose, the valve is subdivided into seven adequate subdivisions to better assess the effect of each engine parts, therefore, an average value of the transient heat transfer coefficient (HTC) and the adiabatic wall temperature (AWT) for each subdivisions are evaluated during one cycle. These two parameters are introduced as boundary condition in a FEM model. The simulations are done at diverse engine regime, and therefore, the trend of the real boundary condition in term of HTC and AWT are given versus engine speed at different load. The findings show that the HTC increases linearly with engine speed however, the AWT decrease slightly at partial load and increase in the case of full engine load. The obtained model is used to highlight the temperature map, which will certainly help to avoid any damage to the exhaust valve.

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A calculation method and experiment study of high-pressure common rail injection rate with solenoid injectors

Science Progress ◽

10.1177/00368504211026157 ◽

2021 ◽

Vol 104 (2) ◽

pp. 003685042110261

Author(s):

Ziguang Gao ◽

Guoxiu Li ◽

Chunlong Xu ◽

Hongmeng Li ◽

Min Wang

Keyword(s):

High Pressure ◽

Input Data ◽

Fuel Injection ◽

Injection Rate ◽

Common Rail ◽

Common Rail System ◽

Rail System ◽

Rate Profile ◽

Fuel Injection Rate ◽

High Pressure Common Rail

The high-pressure common rail system has been widely used owing to its precise control of fuel injection rate profile, which plays a decisive role in cylinder combustion, atomization, and emission. The fuel injection rate profile of high-pressure common rail system was studied, and a fuel injection rate profile calculation model is proposed. The model treats the injector as a black box. Some measured data are needed to calculate the parameters in the model. The rise and fall of injection rate is regarded as trigonometric function to reduce the complexity and increase the accuracy. The model was verified using two different types of fuel injectors. The model calculation results were evaluated under various data input conditions. The results show that the model has good applicability to different input data and injectors. In addition, because the model building requires a large amount of experimental data, a comprehensive analysis of various input data was also conducted. The injection profile was analyzed from a new perspective and the regularity of injection rate profile was established.

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Application of a zero-dimensional model to assess the effect of swirl on indicated efficiency

International Journal of Engine Research ◽

10.1177/1468087418779726 ◽

2018 ◽

Vol 20 (8-9) ◽

pp. 837-848 ◽

Cited By ~ 3

Author(s):

Alberto Broatch ◽

Jaime Martín ◽

Antonio García ◽

Diego Blanco-Cavero ◽

Alok Warey ◽

...

Keyword(s):

Heat Transfer ◽

Engine Speed ◽

Combustion Engine ◽

Combustion Velocity ◽

Combustion Process ◽

Dimensional Model ◽

Trade Offs ◽

High Engine Speed ◽

Rate Of Heat Release ◽

The Impact

Increasing internal combustion engine efficiency continues being one of the main goals of engine research. To achieve this objective, different engine strategies are being developed continuously. However, the assessment of these techniques is not straightforward due to their influence on various intermediate phenomena inherent to the combustion process, which finally result in indicated efficiency trade-offs. During this work, a new methodology to assess these intermediate imperfections on gross indicated efficiency using a zero-dimensional model is developed. This methodology is applied to a swirl parametric study, where it has been concluded that the heat transfer and the rate of heat release are the single relevant changing phenomena. Results show that heat transfer always increases with swirl affecting negatively gross indicated efficiency (around −0.5%), while the impact of combustion velocity is not monotonous. It is enhanced up to a certain swirl ratio (it changes with engine speed) at low engine speed (resulting in an increment of +1.7% in gross indicated efficiency), but it is slowed down at high engine speed with the consequent worsening of gross indicated efficiency (−0.8%).

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Development of an Efficient Conjugate Heat Transfer Modeling Framework to Optimize Mixing-Limited Combustion of Ethanol in a Diesel Engine

ASME 2020 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2020-2946 ◽

2020 ◽

Author(s):

Gina M. Magnotti ◽

Chinmoy K. Mohapatra ◽

Alireza Mashayekh ◽

Sameera Wijeyakulasuriya ◽

Robert Schanz ◽

...

Keyword(s):

Heat Transfer ◽

Diesel Engine ◽

Thermal Efficiency ◽

Conjugate Heat Transfer ◽

Design Parameters ◽

Modeling Framework ◽

Percentage Point Increase ◽

Piston Bowl ◽

Point Increase ◽

Alcohol Fuels

Abstract Long-term petroleum prices and increasingly-stringent emissions regulations are driving manufacturers and users alike to consider alternatives to diesel-fueled engines. Mixing controlled combustion of alcohol fuels, such as ethanol, has been identified as a promising technology based the low propensity for particulate and NOx production, but the higher heats of vaporization and auto-ignition temperatures of these fuels make their direct use in diesel engine architectures a challenge. However, because alcohol fuels do not form appreciable levels of soot even in mixing-controlled (MCCI) mode, and because stoichiometric air/fuel ratios (AFR) can be used to simplify NOx aftertreatment, engine design optimization efforts can be targeted to maximize thermal efficiency. Therefore, to realize the potential of alcohol-fueled combustion, engineering insight is required to understand how design parameters, such as increased engine insulation, piston bowl geometry, or spray targeting, should be optimally utilized. In this work, a computational fluid dynamics (CFD) modeling framework is developed and validated in order to identify pathways to improve the performance of an ethanol-fueled engine operating in an MCCI mode at a stoichiometric AFR. To evaluate the use of TBCs as an engine insulation method, a simplified 1-D conjugate heat transfer (CHT) modeling framework is employed. The CFD model is first validated against baseline engine data over selected inlet air heating temperatures for two piston bowl-injector configurations that define the extrema of the design space. The addition of the 1-D CHT model only increases the computational expense by 15% relative to traditional approaches, yet offers more accurate heat transfer predictions over constant temperature boundary conditions. The model is then used to explore the efficacy of injector orientations and piston bowl geometries in improving the indicated thermal efficiency of alcohol fueled compression ignition engines. Using a design of experiments approach, several candidate designs were identified that improved fuel-air mixing, shortened the combustion duration, and increased thermal efficiency. The most promising design was then fabricated and tested in a Caterpillar 1Y3700 Single Cylinder Oil Test Engine (SCOTE). The engine testing confirmed the findings from the CFD simulations, and found that the co-optimized injector and piston bowl design yielded over 2-percentage point increase in thermal efficiency at the same equivalence ratio (0.96) and over 6-percentage point increase at the same engine load (10.1 bar indicated mean effective pressure), while satisfying design constraints for peak pressure and maximum pressure rise rate.

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Effect and Optimization of Performance of Ceramic Coated Internal Combustion Engine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.766-767.546 ◽

2015 ◽

Vol 766-767 ◽

pp. 546-550

Author(s):

E.V.V. Ramanamurthy ◽

Nishant Gaurav ◽

Abhiyan Paudel ◽

Jasleen

Keyword(s):

Heat Transfer ◽

Internal Combustion Engine ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Engine Speed ◽

Combustion Engine ◽

Internal Combustion ◽

Volumetric Efficiency ◽

Optimum Process ◽

Co Emission

Ceramic coating on the internal combustion engine has appeared as one of the great means that increase performance and efficiency of an engine. This paper presents a novel approach for the optimization and study of the effect of performance of ceramic coated internal combustion engine. In this paper, different parameters like engine load and engine speed are optimized with the consideration of various responses such as engine power output, volumetric efficiency, heat transfer rate to coolant and carbon monoxide (CO) emission. Experiments are carried out by varying the parameters of load and engine speed of ceramic coated internal combustion engine. Orthogonal array is taken to conduct the experiments with the load of 40 Nm, 120 Nm, 200 Nm and speed of 1200, 2000 and 2800 in rev/min. This method shows a good convergence with the experimental and optimum process parameters where maximum volumetric efficiency, minimum heat transfer rate and minimum CO emission are obtained by using the grey relational analysis method.

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Heat Transfer Characteristics in Exhaust Port for Hydrogen Fueled Port Injection Engine: A Transient Approach

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.152-153.1909 ◽

2010 ◽

Vol 152-153 ◽

pp. 1909-1914 ◽

Cited By ~ 1

Author(s):

Md. Mustafizur Rahman ◽

Khalaf I. Hamada ◽

M.M. Noor ◽

K. Kadirgama ◽

Rosli A. Bakar ◽

...

Keyword(s):

Heat Transfer ◽

Engine Speed ◽

Combustion Engine ◽

Rapid Change ◽

Transient Heat Transfer ◽

Power Stroke ◽

Heat Transfer Characteristics ◽

Exhaust Port ◽

Engine Model ◽

Transfer Characteristics

This paper was investigated the transient heat transfer characteristics in exhaust port for hydrogen fueled port injection internal combustion engine (H2ICE). One dimensional gas dynamics was described the flow and heat transfer in the components of the engine model. The engine model is simulated with variable engine speed and air fuel ratio (AFR). Engine speed varied from 2000 rpm to 5000 rpm with increment equal to 1000 rpm and AFR was varies from stoichiometric to lean limit. The effects of AFR and engine speed on heat transfer characteristics for the exhaust port are also investigated. The baseline engine model is verified with previous published results. The obtained results clarify that transient heat transfer process inside exhaust port for port injection H2ICE were affected by the engine speed and AFR. It can be seen that for obtained results clarify that for transient analysis, the fluctuation with very small amplitudes for heat transfer coefficient and heat transfer rate during the compression, intake and part of power stroke. The rapid change for both of them occurs during the exhaust and part of power stroke due to the exhaust valve is open. The obtained results from the simulation can be employed to examine the emission production and engine performance.

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Optimal Design of Conventional In-Line Fuel Injection Equipment

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/pime_proc_1995_209_194_02 ◽

1995 ◽

Vol 209 (2) ◽

pp. 135-141 ◽

Cited By ~ 12

Author(s):

B Kegl

Keyword(s):

High Pressure ◽

Optimal Design ◽

Objective Function ◽

Fuel Injection ◽

Design Procedure ◽

Injection Rate ◽

Design Parameters ◽

Special Treatment ◽

Mathematical Programming Problem ◽

Injection Equipment

The paper describes an application of optimal design procedure employed on conventional in-line fuel injection equipment for a diesel engine. The procedure is applied to a set of design parameters concerning the design of the cam, high-pressure pump, delivery valve, snubber valve, high-pressure tube and injector respectively. The values of these design parameters are optimized simultaneously within specified maximum and minimum values in order to approach a target injection rate history. The proposed optimal design procedure is defined as a solution process of a non-linear mathematical programming problem defined by the objective and constraint functions. The objective function measures the difference between the target and actual injection rate histories while the constraints concern the response of the system as well as several technological limitations. The form of the objective function is such that it requires special treatment similar to those employed in optimal design of dynamic multi-body systems. However, the complexity of the fuel injection equipment causes specific numerical difficulties when the ideas employed for dynamic systems are adopted. The paper describes how to modify the usual approach in order to circumvent these difficulties. The theory is illustrated with a numerical example comparing the usual versus the modified approach.

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Effect of Chemical Hythane Composition on Pressure in Combustion Chamber of Engine

Alternative Energy and Ecology (ISJAEE) ◽

10.15518/isjaee.2019.10-12.036-042 ◽

2019 ◽

pp. 36-42

Author(s):

A. P. Shaikin ◽

I. R. Galiev

Keyword(s):

Natural Gas ◽

Combustion Chamber ◽

Power Plants ◽

Engine Speed ◽

Combustion Engine ◽

Fuel Mixture ◽

Maximum Pressure ◽

Chamber Volume ◽

Excess Air ◽

Scientific Papers

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.

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