Spark Advance Modeling of Hydrogen-Fueled Spark Ignition Engines Using Combustion Descriptors

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Saket Verma ◽  
L. M. Das
Keyword(s):  
Numerical Simulation ◽  
Alternative Fuels ◽  
System Development ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Ansys Fluent ◽  
Engine Design ◽  
Pressure Peak ◽  
Si Engines ◽  
Computational Fluid Dynamics Cfd

In-cylinder pressure-based combustion descriptors have been widely used for engine combustion control and spark advance scheduling. Although these combustion descriptors have been extensively studied for gasoline-fueled spark ignition (SI) engines, adequate literature is not available on use of alternative fuels in SI engines. In an attempt to partially address this gap, present work focuses on spark advance modeling of hydrogen-fueled SI engines based on combustion descriptors. In this study, two such combustion descriptors, namely, position of the pressure peak (PPP) and 50% mass fraction burned (MFB) have been used to evaluate the efficiency of the combustion. With a view to achieve this objective, numerical simulation of engine processes was carried out in computational fluid dynamics (CFD) software ANSYS fluent and simulation data were subsequently validated with the experimental results. In view of typical combustion characteristics of hydrogen fuel, spark advance plays a very crucial role in the system development. Based on these numerical simulation results, it was observed that the empirical rules used for combustion descriptors (PPP and 50% MFB) for the best spark advance in conventional gasoline fueled engines do not hold good for hydrogen engines. This work suggests revised empirical rules as: PPP is 8–9 deg after piston top dead center (ATDC) and position of 50% MFB is 0–1 deg ATDC for the maximum brake torque (MBT) conditions. This range may vary slightly with engine design but remains almost constant for a particular engine configuration. Furthermore, using these empirical rules, spark advance timings for the engine are presented for its working range.

scholarly journals Performance of Anisole and Isobutanol as Gasoline Bio-Blendstocks for Spark Ignition Engines

2021 ◽  
Vol 13 (16) ◽  
pp. 8729
Author(s):  
Michał Wojcieszyk ◽  
Lotta Knuutila ◽  
Yuri Kroyan ◽  
Mário de Pinto Balsemão ◽  
Rupali Tripathi ◽  
...  
Keyword(s):  
Alternative Fuels ◽  
Ghg Emissions ◽  
Spark Ignition ◽  
Liquid Fuels ◽  
Transport Sector ◽  
Ternary Blend ◽  
Spark Ignition Engines ◽  
Si Engines ◽  
Unburned Hydrocarbons ◽  
End Use

Several countries have set ambitious targets for the transport sector that mandate a gradual increase in advanced biofuel content in the coming years. The current work addresses this transition and indicates two promising gasoline bio-blendstocks: Anisole and isobutanol. The whole value chains of these bio-components were considered, focusing on end-use performance, but also analyzing feedstock and its conversion, well-to wheel (WTW) greenhouse gas (GHG) emissions and costs. Three alternative fuels, namely a ternary blend (15% anisole, 15% isobutanol, 70% fossil gasoline on an energy basis) and two binary blends (15% anisole with fossil gasoline and 30% isobutanol with fossil gasoline), were tested, focusing on their drop-in applicability in spark ignition (SI) engines. The formulated liquid fuels performed well and showed the potential to increase brake thermal efficiency (BTE) by 1.4% on average. Measured unburned hydrocarbons (HC) and carbon monoxide (CO) emissions were increased on average by 12–29% and 17–51%, respectively. However, HC and CO concentrations and exhaust temperatures were at acceptable levels for proper catalyst operation. The studied blends were estimated to bring 11–22% of WTW GHG emission reductions compared to base gasoline. Additionally, the fleet performance and benefits of flexi-fuel vehicles (FFV) were modeled for ternary blends.

scholarly journals Ethanol/Gasoline Blends as Alternative Fuel in Last Generation Spark-Ignition Engines: A Review on CO and HC Engine Out Emissions

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone
Keyword(s):  
Physicochemical Properties ◽  
Alternative Fuels ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
The Impact

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.

A New Approach for Ignition Timing Correction in Spark Ignition Engines Based on Cylinder Tendency to Surface Ignition

2016 ◽  
Vol 819 ◽  
pp. 272-276 ◽  
Author(s):  
Ali Ghanaati ◽  
Mohd Farid Muhamad Said ◽  
Intan Zaurah Mat Darus ◽  
Amin Mahmoudzadeh Andwari
Keyword(s):  
Spark Ignition ◽  
Combustion Stability ◽  
Spark Ignition Engines ◽  
Gas Temperature ◽  
New Approach ◽  
Surface Ignition ◽  
Spark Plug ◽  
Engine Combustion ◽  
Si Engines ◽  
Exhaust Gas Temperature

The performance of Spark Ignition (SI) engines in terms of thermal efficiency can be restricted by knock. Although it is common for all SI engines to exhibit knock from compressed end-gas, knocks from surface ignition remains a more serious problem due to its effect on combustion stability and its obscurity to detect. This paper focuses on predicting the occurrence of knocks from surface ignition by monitoring exhaust gas temperature (EGT). EGT measured during an engine cycle without the spark plug firing. Therefore, EGT rises illustrated any combustion made by surface ignition. Modelling and simulation of a one-dimensional engine combustion done by using GT-Power. The new approach reduces the complexity as EGT monitoring does not require high computational demands, and the EGT signals are robust to noise. The method is validated against a variety of fuel properties and across engine conditions. A new approach is proposed as a measure to predict and detect the knock events.

scholarly journals A Fast CFD-Based Methodology for Determining the Cyclic Variability and Its Effects on Performance and Emissions of Spark-Ignition Engines

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4131
Author(s):  
George M. Kosmadakis ◽  
Constantine D. Rakopoulos
Keyword(s):  
Spark Ignition ◽  
Pollutant Emissions ◽  
Computational Time ◽  
Spark Ignition Engines ◽  
Cyclic Variability ◽  
Indicated Mean Effective Pressure ◽  
Spark Plug ◽  
Performance And Emissions ◽  
Si Engines ◽  
Cyclic Variations

A methodology for determining the cyclic variability in spark-ignition (SI) engines has been developed recently, with the use of an in-house computational fluid dynamics (CFD) code. The simulation of a large number of engine cycles is required for the coefficient of variation (COV) of the indicated mean effective pressure (IMEP) to converge, usually more than 50 cycles. This is valid for any CFD methodology applied for this kind of simulation activity. In order to reduce the total computational time, but without reducing the accuracy of the calculations, the methodology is expanded here by simulating just five representative cycles and calculating their main parameters of concern, such as the IMEP, peak pressure, and NO and CO emissions. A regression analysis then follows for producing fitted correlations for each parameter as a function of the key variable that affects cyclic variability as has been identified by the authors so far, namely, the relative location of the local turbulent eddy with the spark plug. The application of these fitted correlations for a large number of engine cycles then leads to a fast estimation of the key parameters. This methodology is applied here for a methane-fueled SI engine, while future activities will examine cyclic variations in SI engines when fueled with different fuels and their mixtures, such as methane/hydrogen blends, and their associated pollutant emissions.

scholarly journals Numerical simulation of the flow into a circular pipe section

2019 ◽  
Vol 85 ◽  
pp. 02005
Author(s):  
Gelu Muscă ◽  
George Mădălin Chitaru ◽  
Costin Ioan Coşoiu ◽  
Cătalin Nae
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Fluid Motion ◽  
Experimental Tests ◽  
Navier Stokes ◽  
Ansys Fluent ◽  
Turbulent Airflow ◽  
Quantitative Results ◽  
Computational Fluid Dynamics Cfd ◽  
Unsteady Numerical Simulation

Computational Fluid dynamics (CFD) is the science that evolves rapidly in numerical solving of fluid motion equations to produce quantitative results and analyses of phenomena encountered in the fluid flow. When properly used, CFD is often ideal for parameterization studies or physical significance investigations of flow that would otherwise be impossible to replicate through theoretical or experimental tests. The aim of this paper is the study of the turbulent airflow and how the vortices formed in turbulent airflow are influenced by the evolution of the hydraulic characteristics of the fluid flow. Unsteady numerical simulation were performed using Reynolds Average Navier-Stokes (RANS) turbulence model adapted to conventional flow into a pipe with variable section which was implemented in the ANSYS FLUENT expert software.

Numerical Simulation of a Spark Ignition Engine Using Liquid Fuels and Liquid Fuel Blends

2003 ◽  
Author(s):  
K. Majmudar ◽  
K. Aung
Keyword(s):  
Numerical Simulations ◽  
Liquid Fuel ◽  
Alternative Fuels ◽  
Current Model ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Liquid Fuels ◽  
Si Engine ◽  
Fuel Blends ◽  
Si Engines

The use of alternative fuels such as methanol and ethanol in spark-ignition (SI) engines is beneficial to the environment as it reduces emissions of pollutants such as NOx from these engines with slight penalty on the performance. This paper investigated the use of liquid fuel blends such as ethanol/gasoline blend in an SI engine by numerical simulations. The numerical simulations were based on the models of finite heat release, cylinder heat transfer, pumping losses, and friction losses. Simulations were carried out to evaluate the effects of compression ratio, equivalence ratio, ignition timing, and engine speed on the performance of the SI engine. The results of the simulations were compared with experimental data from the literature to validate the simulations. Good agreements between the computed and experimental results were obtained. The results showed that the current model could satisfactorily predict the performance of an SI engine fueled by liquid fuel blends.

Theoretical and Experimental Researches Regard the Use of Bioethanol at the Supercharged Spark Ignition Engine

2016 ◽  
Vol 822 ◽  
pp. 190-197
Author(s):  
Obeid Zuhair H. Obeid ◽  
Constantin Pana ◽  
Niculae Negurescu ◽  
Alexandru Cernat ◽  
Iulius Bondoc
Keyword(s):  
Combustion Process ◽  
Alternative Fuel ◽  
Good Alternative ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Experimental Investigations ◽  
Spark Ignition Engines ◽  
Local Cooling ◽  
Combustion Properties ◽  
Si Engines

The use of bioethanol as alternative fuel for automotive supercharged spark ignition engines is required especially for to respect the pollutant norms which become more and more severe, especially for NOx emissions.The general objective of the researches is improving of a automotive supercharged spark ignition engine efficiency, improving performance of power and torque and decreasing of the emissions level by the use of bioethanol. Bioethanol is so a very good alternative fuel for SI engines because of its better combustion proprieties comparative to the gasoline as a good cooling agent of the intake air due to its high vaporization heat.The paper presents results of some theoretical and experimental investigations on a 1.5 L supercharged SI engine fuelled with gasoline-bioethanol blends. The investigations show that the improvement of the combustion process by use the bioethanol at the supercharged spark ignition engine leads to the reduction of BSFC, to the accentuated reduction CO and HC due to a lower C content and better combustion properties of the bioethanol. In same time, the NOx emissions level significantly decreases because of the local cooling effect produced by bioethanol vaporization.

A Quasi-dimensional Model of the Ignition Delay for Combustion Modeling in Spark-Ignition Engines

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Sebastian Grasreiner ◽  
Jens Neumann ◽  
Michael Wensing ◽  
Christian Hasse
Keyword(s):  
Ignition Delay ◽  
Direct Injection ◽  
Control Unit ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Combustion Modeling ◽  
Crank Angle ◽  
Si Engines ◽  
Engine Map ◽  
Start Of Combustion

Quasi-dimensional (QD) modeling of combustion in spark-ignition (SI) engines allows to describe the most relevant processes of heat release. Here, a submodel for the ignition delay is introduced and applied. The start of combustion is considered from ignition to the crank angle of 5% burned gas fraction. The introduced physical approach identifies the turbulent propagation velocity of the initiated kernel by taking into account early flame expansion and geometric restrictions of the flame propagation. The model is applied to stationary operation within an entire engine map of a turbocharged direct injection SI engine with fully variable valvetrain. Based on provided cycle-averaged input data, the model delivers good results within the margins of measured cycle-to-cycle fluctuations. Thus, it contributes to the assessment of the interplay between engine, engine control unit, drivetrain, and vehicle dynamics, hence making a step toward optimization and virtual engine calibration.

Numerical Simulation of Insulin Depot Formation in Subcutaneous Tissue

2016 ◽  
Author(s):  
Michael M. Zedelmair ◽  
Abhijit Mukherjee
Keyword(s):  
Numerical Simulation ◽  
Insulin Pump ◽  
Subcutaneous Tissue ◽  
Saturated Porous Media ◽  
Lateral Direction ◽  
Ansys Fluent ◽  
Computational Fluid Dynamics Cfd ◽  
Experimental Findings ◽  
Subcutaneous Adipose ◽  
Adipose Cells

In this study a numerical model of the insulin depot formation and absorption in the subcutaneous adipose tissue is developed using the commercial Computational Fluid Dynamics (CFD) software ANSYS Fluent. A better understanding of these mechanisms can be helpful in the development of new devices and cannula geometries as well as predicting the concentration of insulin in the blood. The injection method considered in this simulation is by the use of an insulin pump using a rapid acting U100 insulin analogue. The insulin is injected into the subcutaneous tissue in the abdominal region. The main composition of the subcutaneous tissue is blood vessels and adipose cells surrounded by interstitial fluid. The numerical simulation is conducted in a 2D-axisymmetric domain where the tissue is modeled as a fluid saturated porous media. Due to the presence of channel formation in lateral direction in the tissue, an anisotropic approach to define the permeability is studied having an impact on the viscous resistance to the flow. This configuration is resulting in a rather disk shaped depot following recent experimental findings. The depot formation is analyzed running Bolus injections ranging from 5–15 Units of insulin corresponding to 50–150μl. The depot formation model has been extended implementing the process of absorption of insulin from the depot to be able to run the simulation over longer timeframes where absorption starts playing an important role.

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