Analyzing the Effect of Engine Design Modification on the Spark-Ignition Engine Performance via Simplified Quasi-Dimensional Modeling

2017 ◽  
Author(s):  
Yirop Kim ◽  
Myoungsoo Kim ◽  
Han Ho Song
Keyword(s):  
Burning Rate ◽  
Engine Performance ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Optimization Process ◽  
Design Parameters ◽  
Ic Engine ◽  
Design Modification ◽  
Engine Design ◽  
Flow Motion

For past decades, substantial developments have been accomplished in internal combustion (IC) engine technology, but there still remain some possible improvements. The combustion in an IC engine is a highly intricate phenomenon, thus, numerous factors correlated with different forms of loss decides the efficiency of an engine. In spark-ignition (SI) engines, the combustion duration is considered important because it plays a key role in determining the combustion phasing for best possible energy conversion. The geometry of engine components may directly change the burning rate of air-fuel mixture, therefore, it should also be considered as significant as other aspects like exhaust gas recirculation (EGR) rate or boosting in investigation of the engine performance. This is the reason the development engineers are putting their effort to design an engine with optimized flow motion. Tweaking the flow dynamics via design modification or use of auxiliary device influences the turbulence level inside the combustion chamber, thus, the burning rate as well. Intake port orientation, masking, and piston shape are one of the typical design parameters manipulated for such purpose, and profound understanding on the effect of these design parameters on burning rate is encouraged in order to assist the optimization process. The design optimization process should be based on a fundamental understanding of how the design parameters affect the flow motion and combustion characteristics. This study aims for a simpler and faster method to investigate the consequences of design modifications. As a base model, a physics-based quasi-dimensional (QD) engine model is developed for simulation of SI combustion phenomenon. It is modeled to consider the change in flow motion and turbulence properties via simplified modeling. The advantages of such QD model is that it requires much less computational resource compared to 3D CFD model, and allows a greater degree of freedom within the simulation process which facilitates parametric studies. A zero-dimensional (0D) turbulence submodel is used to describe energy cascade mechanism, and turbulence intensity is calculated reflecting the effect cause by design modification. According to the sensitivities drawn from parametric study, the results of each effect on burning rate and other engine performance properties are compared individually and collectively. A qualitative analysis suggests how sensitive each effect are at given operating conditions. The result infers that the flow concentration by port design modification boosts the burning rate, but it is advantageous in terms of fuel economy to enhance the breathing ability by valve masking. The product of this comparative study assists an intuitive understanding on how the design modification would affect the engine operations, and it is encouraged to develop the model further via validation with experiment data to provide more reliable output. It is believed that it can be utilized as a good reference in engine design process.

The Operational Mixture Limits in Engines Fueled With Alternative Gaseous Fuels

2006 ◽  
Vol 128 (3) ◽  
pp. 223-228 ◽  
Author(s):  
S. O. Bade Shrestha ◽  
Ghazi A. Karim
Keyword(s):  
Engine Performance ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Design Parameters ◽  
Compression Ignition ◽  
Gaseous Fuels ◽  
Compression Ignition Engines ◽  
Wide Range ◽  
Operational Life ◽  
Experimental Values

The operation of engines whether spark ignition or compression ignition on a wide range of alternative gaseous fuels when using lean mixtures can offer in principle distinct advantages. These include better economy, reduced emissions, and improved engine operational life. However, there are distinct operational mixture limits below which acceptable steady engine performance cannot be sustained. These mixture limits are usually described as the “lean operational limits,” or loosely as the ignition limits which are a function of various operational and design parameters for the engine and fuel used. Relatively simple approximate procedures are described for predicting the operational mixture limits for both spark ignition and dual fuel compression ignition engines when using a range of common gaseous fuels such as natural gas/methane, propane, hydrogen, and some of their mixtures. It is shown that good agreement between predicted and corresponding experimental values can be obtained for a range of operating conditions for both types of engines.

scholarly journals Estimation of a Spark Ignition Engine’s Performance Parameters for Ethanol-Gasoline blends using Response Surface Methodology

2019 ◽  
Vol 8 (10) ◽  
pp. 2092-2099
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Engine Performance ◽  
Spark Ignition ◽  
Ic Engine ◽  
Brake Thermal Efficiency ◽  
Performance And Emission ◽  
Engine Design ◽  
Ethanol Blends ◽  
Rsm Model

The Internal Combustion(IC) engine design and growth plays an important role in determining engine performance and emission features. The performance and emission properties of the spark ignition (SI) motor are also more influenced by gasoline ethanol blends. In this work, an effort has been made to optimize the operating parameters in order to minimize BSFC, CO, NO2 , CO2 , HC and maximize BTE using Response Surface Methodology (RSM). The engine is operated under constant speed conditions with different working conditions for better mixing and distinct additive composition (iso-octane) in the range of 0.3%, 0.4% and 0.5%. The appropriate RSM was used to reduce the use of petrol, its exhausts and maximize Brake Thermal Efficiency. The experimental and statistical approximation demonstrates the rise in Thermal Brake Efficiency (BTE) and decline in Specific Brake Fuel Consumption (BSFC). In addition, the chosen RSM model demonstrates reduced CO, HC, NO2 and CO2 emissions. From the assessment, it is noted that E30 mix with 0.5% additive has better motor efficiency features and reduced emissions at a peak speed of 1800rpm among all test blends with varying proportion of additives.

The Operational Mixture Limits in Engines Fueled With Alternative Gaseous Fuels

2005 ◽  
Author(s):  
S. O. Bade Shrestha ◽  
Ghazi A. Karim
Keyword(s):  
Engine Performance ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Design Parameters ◽  
Compression Ignition ◽  
Gaseous Fuels ◽  
Compression Ignition Engines ◽  
Wide Range ◽  
Operational Life ◽  
Experimental Values

The operation of engines whether spark ignition or compression ignition on a wide range of alternative gaseous fuels when using lean mixtures, can offer in principle distinct advantages. These include better economy, reduced emissions and improved engine operational life. However, there are distinct operational mixture limits below which acceptable steady engine performance cannot be sustained. These mixture limits are usually described as the “lean operational limits”, or loosely as the ignition limits which are a function of various operational and design parameters for the engine and fuel used. Through experimental investigation and analytical simulation of engine performance, relatively simple approximate procedures are described for predicting the operational mixture limits for both spark ignition and dual fuel compression ignition engines when using a range of common gaseous fuels such as natural gas/methane, propane, hydrogen and some of their mixtures. It is to be shown that good agreement between the predicted and corresponding experimental values can be obtained for a range of operating conditions for both types of engines.

Ethers and esters as alternative fuels for internal combustion engine: A review

2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua
Keyword(s):  
Alternative Fuels ◽  
Combustion Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Engine Performance ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Future Research ◽  
Particulate Emissions ◽  
Ic Engine

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.

scholarly journals A Numerical Model to Study the Role of Surface Textures at Top Dead Center Reversal in the Piston Ring to Cylinder Liner Contact

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
N. Morris ◽  
R. Rahmani ◽  
H. Rahnejat ◽  
P. D. King ◽  
S. Howell-Smith
Keyword(s):  
Gas Flow ◽  
Fuel Efficiency ◽  
Surface Texturing ◽  
Engine Performance ◽  
Cylinder Liner ◽  
Operating Conditions ◽  
Ic Engine ◽  
Numerical Predictions ◽  
Combined Solution ◽  
Effect Of Surface

Minimization of parasitic losses in the internal combustion (IC) engine is essential for improved fuel efficiency and reduced emissions. Surface texturing has emerged as a method palliating these losses in instances where thin lubricant films lead to mixed or boundary regimes of lubrication. Such thin films are prevalent in contact of compression ring to cylinder liner at piston motion reversals because of momentary cessation of entraining motion. The paper provides combined solution of Reynolds equation, boundary interactions, and a gas flow model to predict the tribological conditions, particularly at piston reversals. This model is then validated against measurements using a floating liner for determination of in situ friction of an engine under motored condition. Very good agreement is obtained. The validated model is then used to ascertain the effect of surface texturing of the liner surface during reversals. Therefore, the paper is a combined study of numerical predictions and the effect of surface texturing. The predictions show that some marginal gains in engine performance can be expected with laser textured chevron features of shallow depth under certain operating conditions.

CFD Simulation of an Alfa-Stirling Engine to Study the Geometrical Parameters on the Engine Performance

2019 ◽  
Author(s):  
Ana C. Ferreira ◽  
Senhorinha F. C. F. Teixeira ◽  
Ricardo F. Oliveira ◽  
José C. Teixeira
Keyword(s):  
Heat Exchanger ◽  
Power Output ◽  
Cfd Simulation ◽  
Engine Performance ◽  
Stirling Engine ◽  
Operating Conditions ◽  
Design Parameters ◽  
Working Fluid ◽  
Cold Temperatures ◽  
Temperature Heat

Abstract An alpha-Stirling configuration was modelled using a Computational Fluid Dynamic (CFD), using ANSYS® software. A Stirling engine is an externally heated engine which has the advantage of working with several heat sources with high efficiencies. The working gas flows between compression and expansion spaces by alternate crossing of, a low-temperature heat exchanger (cooler), a regenerator and a high-temperature heat exchanger (heater). Two pistons positioned at a phase angle of 90 degrees were designed and the heater and cooler were placed on the top of the pistons. The motion of the boundary conditions with displacement was defined through a User Defined Function (UDF) routine, providing the motion for the expansion and compression piston, respectively. In order to define the temperature differential between the engine hot and the cold sources, the walls of the heater and cooler were defined as constant temperatures, whereas the remaining are adiabatic. The objective is to study the thermal behavior of the working fluid considering the piston motion between the hot and cold sources and investigate the effect of operating conditions on engine performance. The influence of regenerator matrix porosity, hot and cold temperatures on the engine performance was investigated through predicting the PV diagram of the engine. The CFD simulation of the thermal engine’s performance provided a Stirling engine with 760W of power output. It was verified that the Stirling engine can be optimized when the best design parameters combination are applied, mostly the regenerator porosity and cylinders volume, which variation directly affect the power output.

Finite Element Modeling of Piston-Ring Dynamics and Blowby Estimation in Single-Cylinder IC Engine

2002 ◽  
Author(s):  
S. N. Kurbet ◽  
R. Krishna Kumar
Keyword(s):  
Thermal Properties ◽  
Radial Direction ◽  
Piston Ring ◽  
Engine Performance ◽  
Mechanical And Thermal Properties ◽  
Ic Engine ◽  
Development Cycle ◽  
Engine Design ◽  
Ring Dynamics ◽  
Engine Testing

The ring geometry, its assembly load and its mechanical and thermal properties are factors that influence engine performance. The ring dynamics is greatly influenced by piston secondary motions that depend upon the piston geometry, piston pin offset, its center of gravity (C.G.) location and piston-liner clearance. The engine is simulated to study the rings motion in axial, radial direction and the gap areas are calculated to estimate blowby and compared with experimental results. This approach to engine design reduces the conceptual design-to-development cycle time and reduces the need of extensive engine testing for evaluating ring performance.

Thermal Analysis of Radiator Core in Heavy Duty Automobile

2008 ◽  
Author(s):  
Srikanth Kolachalama ◽  
Kalyan Kuppa ◽  
Dhananjay Mattam ◽  
Mukul Shukla
Keyword(s):  
Internal Combustion Engines ◽  
Heat Dissipation ◽  
Cooling System ◽  
Engine Performance ◽  
Mathematical Expression ◽  
Helical Structure ◽  
Design Parameters ◽  
Combustion Engines ◽  
Engine Design ◽  
Coefficient Of Thermal Conductivity

Background: Heat dissipation is one of the most critical considerations in engine design and with an efficient cooling system; performance of the engine can be dramatically improved. All internal combustion engines convert chemical energy into mechanical power. Around 70% of the energy is converted into heat and therefore, the primary job of the cooling system is to keep the engine from overheating by transferring this heat to the air. A radiator transfer’s heat from the hot coolant to the air and an effective design of radiator will ultimately lead to enhanced engine performance by reducing the heating effect. Methods and results: A mathematical expression for the rate of heat dissipation from the radiator core was derived and a modification in the design was proposed in the radiator core by changing the structure of the tubes from cylindrical to helical. The rate of heat dissipation for both designs was compared with similar boundary conditions by varying the magnitude of all design parameters in a specific range that have same magnitude of area of cross section, length of the radiator core and coefficient of thermal conductivity for the tube. Enhanced rate of heat dissipation for helical structure confirms the efficacy of the proposed design.

Areo-Engine Cycle Parametric Analysis and Installed Performance Calculation Based on Aircraft Flight Mission

2013 ◽  
Vol 482 ◽  
pp. 277-281 ◽  
Author(s):  
Hong Zhou ◽  
Zhan Xue Wang ◽  
Xiao Bo Zhang
Keyword(s):  
Parametric Analysis ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Aircraft Flight ◽  
Performance Requirements ◽  
Engine Design ◽  
Performance Specifications ◽  
Performance Calculation ◽  
Engine Cycle

The aircraft/engine integration design numerical simulation model was established. The engine design performance specifications were obtained by calculating aircraft lift-drag characteristics, mission analysis, constraint analysis. Combining engine cycle parametric analysis with installation loss computing, the engine performance parameters can be found, which meet the aircraft flight envelope performance requirements. Taking double bypass variable cycle engine as an example to check the model, the results show that the variable cycle engine can meet aircrafts thrust and fuel consumption demands under different operating conditions, and achieve cruise thrust adjustment at the same inlet mass flow to reduce installation losses.

A Comprehensive Model for Pilot-Ignited, Coal-Water Mixture Combustion in a Direct-Injection Diesel Engine

1990 ◽  
Vol 112 (3) ◽  
pp. 384-390
Author(s):  
S. Wahiduzzaman ◽  
P. N. Blumberg ◽  
R. Keribar ◽  
C. I. Rackmil
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Accurate Determination ◽  
Engine Performance ◽  
Operating Conditions ◽  
Combustion Model ◽  
Water Mixture ◽  
Engine Design ◽  
Pilot Fuel

A combustion model has been developed for a direct-injected diesel engine fueled with coal-water slurry mixture (CWM) and assisted by diesel pilot injection. The model combines the unique heat and mass transport and chemical kinetic processes of CWM combustion with the normal in-cylinder processes of a diesel engine. It includes a two-stage evaporation submodel for the drying of the CWM droplet, a global kinetic submodel for devolatilization, and a char combustion submodel describing surface gasification by oxygen, carbon dioxide, and water vapor. The combustion volume is discretized into multiple zones, each of whose individual thermochemistry is determined by in-situ equilibrium calculations. This provides an accurate determination of the boundary conditions for the CWM droplet combustion submodels and the gas phase heat release. A CWM fuel jet development, entrainment, and mixing submodel is used to calculate the mass of unburned air in each of the burned zones. A separate submodel of diesel pilot fuel combustion is incorporated into the overall model, as it has been found that pilot fuel is required to achieve satisfactory combustion under many operating conditions. The combustion model is integrated with an advanced engine design analysis code. The integrated model can be used as a tool for exploration of the effects of fuel characteristics, fuel injection parameters, and engine design variables on engine performance, and in the assessment of the effects of component design modifications on the overall efficiency of the engine and the degree of coal burnout achieved.

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