Comparison of In-Cylinder Pressure Measurement Methods in a Small Spark Ignition Engine

2014 ◽  
Author(s):  
Joseph K. Ausserer ◽  
Alexander K. Rowton ◽  
Keith D. Grinstead ◽  
Paul J. Litke ◽  
Marc D. Polanka
Keyword(s):  
Pressure Measurement ◽  
Spark Ignition ◽  
Measurement Methods ◽  
Spark Ignition Engine ◽  
Cylinder Pressure

Investigating the Effects of Engine Operating Conditions on the Cyclic Variability of a Commercial Flex-Fuel Engine

2019 ◽  
Author(s):  
Fazal Um Min Allah ◽  
Caio Henrique Rufino ◽  
Waldyr Luiz Ribeiro Gallo ◽  
Clayton Barcelos Zabeu
Keyword(s):  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Cylinder Pressure ◽  
Cyclic Variability ◽  
Indicated Mean Effective Pressure ◽  
Mass Fractions ◽  
Cyclic Variations ◽  
Flex Fuel ◽  
Hydrous Ethanol

Abstract The flex-fuel engines are quite capable of running on gasohol and hydrous ethanol. However, the in-cylinder cyclic variations, which are inherently present in spark-ignition (SI) engines, affect the performance of these engines. Therefore, a comprehensive analysis is required to evaluate the effects of in-cylinder cyclic variations of a flex-fuel engine. The experiments were carried out by using Brazilian commercial Gasohol E27 (mixture of 27% anhydrous ethanol in gasoline) and hydrous ethanol E95h (5% water by volume in ethanol) as fuels for a commercial flex-fuel spark ignition engine. A comparison between the cyclic variations of gasohol and hydrous ethanol is presented in this paper. Moreover, the effects of engine operating parameters (i.e., engine speed, engine load and relative air fuel ratio) on cyclic variations are also investigated. The acquired data of in-cylinder pressure and combustion durations are evaluated by carrying out a statistical analysis. The coefficient of variation for indicated mean effective pressure (IMEP) did not exceed the limit of 5% for all tested conditions. Higher cyclic variability of maximum in-cylinder pressure is observed for gasohol fuel and higher engine speeds. The variability of in-cylinder combustion is also evaluated with the help of different combustion stages, which are characterized by corresponding crank positions of 10%, 50% and 90% mass fractions burned.

Validation of Species-Based Extended Coherent Flamelet Model in a Large Eddy Simulation of a Homogeneous Charge Spark Ignition Engine

2020 ◽  
Author(s):  
Y. See ◽  
M. Wang ◽  
J. Bohbot ◽  
O. Colin
Keyword(s):  
Large Eddy Simulation ◽  
Computational Cost ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Cylinder Pressure ◽  
Flamelet Model ◽  
Progress Variable ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Homogeneous Charge

Abstract The Species-Based Extended Coherent Flamelet Model (SB-ECFM) was developed and previously validated for 3D Reynolds-Averaged Navier-Stokes (RANS) modeling of a spark-ignited gasoline direct injection engine. In this work, we seek to extend the SB-ECFM model to the large eddy simulation (LES) framework and validate the model in a homogeneous charge spark-ignited engine. In the SB-ECFM, which is a recently developed improvement of the ECFM, the progress variable is defined as a function of real species instead of tracer species. This adjustment alleviates discrepancies that may arise when the numerical treatment of real species is different than that of the tracer species. Furthermore, the species-based formulation also allows for the use of second-order numeric, which can be necessary in LES cases. The transparent combustion chamber (TCC) engine is the configuration used here for validating the SB-ECFM. It has been extensively characterized with detailed experimental measurements and the data are widely available for model benchmarking. Moreover, several of the boundary conditions leading to the engine are also measured experimentally. These measurements are used in the corresponding computational setup of LES calculations with SB-ECFM. Since the engine is spark ignited, the Imposed Stretch Spark Ignition Model (ISSIM) is utilized to model this physical process. The mesh for the current study is based on a configuration that has been validated in a previous LES study of the corresponding motored setup of the TCC engine. However, this mesh was constructed without considering the additional cells needed to sufficiently resolve the flame for the fired case. Thus, it is enhanced with value-based Adaptive Mesh Refinement (AMR) on the progress variable to better capture the flame front in the fired case. As one facet of model validation, the ensemble average of the measured cylinder pressure is compared against the LES/SB-ECFM prediction. Secondly, the predicted cycle-to-cycle variation by LES is compared with the variation measured in the experimental setup. To this end, the LES computation is required to span a sufficient number of engine cycles to provide statistical convergence to evaluate the coefficient of variation (COV) in peak cylinder pressure. Due to the higher computational cost of LES, the runtime required to compute a sufficient number of engine cycles sequentially can be intractable. The concurrent perturbation method (CPM) is deployed in this study to obtain the required number of cycles in a reasonable time frame. Lastly, previous numerical and experimental analyses of the TCC engine have shown that the flow dynamics at the time of ignition is correlated with the cycle-to-cycle variability. Hence, similar analysis is performed on the current simulation results to determine if this correlation effect is well-captured by the current modeling approach.

Adaptive in-cylinder pressure model for spark ignition engine control

Fuel ◽  
2021 ◽  
Vol 299 ◽  
pp. 120870
Author(s):  
Benjamín Pla ◽  
Joaquin De La Morena ◽  
Pau Bares ◽  
Irina Jiménez
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Engine Control ◽  
Cylinder Pressure

scholarly journals Analysis of Engine Performance Parameters with Hydrogen Enrichment in Premixed Spark Ignition Engine Using Fuel Blend

2021 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Internal Combustion Engines ◽  
Engine Performance ◽  
Spark Ignition ◽  
Independent Study ◽  
Spark Ignition Engine ◽  
Gasoline Direct Injection ◽  
Pure Hydrogen ◽  
Cylinder Pressure ◽  
Performance Parameters ◽  
Hydrogen Enrichment

Hydrogen enrichment in internal combustion engines has been a topic of research interest to improve engine efficiencies and reduce carbon emissions. Hydrogen enrichment has garnered more interest than the pure hydrogen powered engines due to less complexity involved with the modifications of the engine and fuel system as well as the infrastructure required for it. Similarly, accurate chemical kinetics has proved to provide accurate results in terms of engine performance parameters, such as, in-cylinder pressure. The present study is an extension of study performed earlier with hydrogen enrichment in gasoline direct injection engine while using C8 H17 as a surrogate fuel for gasoline and assumes that an on-board electrolysis system installed on the vehicle produces hydrogen for the enrichment purposes. A mesh independent study is performed using 90% iso-octane (iC8 H18) and 10% n-heptane (nC7 H16) blend as a gasoline surrogate with hydrogen enrichment of 0%, 1%, 2% and 3% at equivalence ratios of 0.98 and 1.3, in a premixed spark ignition engine. Numerical simulations are performed to calculate and compare the thermal and combustion efficiencies of the engine using hydrogen-enriched fuel versus iso-octane and n-heptane blend. The study also predicts and measures the engine performance parameter of in-cylinder pressure, while comparing the iso-octane and n-heptane blend against the blend enriched with hydrogen. Based on the results obtained from smaller hydrogen enrichment concentrations, the study increases the hydrogen-enrichment of the fuel to 5%, 10% and 15% to analyse the effects of enrichment on the thermal and combustion efficiencies, as well as the in-cylinder pressure.

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