scholarly journals Spark-ignition engine speed profile optimization for maximizing the net indicated efficiency and quantitative analysis of the optimal speed profile

2021 ◽  
pp. 118162
Author(s):  
Jeongwoo Song ◽  
Han Ho Song
Keyword(s):  
Quantitative Analysis ◽  
Engine Speed ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Speed Profile ◽  
Optimal Speed ◽  
Profile Optimization

scholarly journals Efficiency characteristics of a new quasi-constant volume combustion spark ignition engine

2013 ◽  
Vol 17 (1) ◽  
pp. 119-133 ◽  
Author(s):  
Jovan Doric ◽  
Ivan Klinar
Keyword(s):  
Engine Speed ◽  
Combustion Process ◽  
Spark Ignition ◽  
Constant Volume ◽  
Spark Ignition Engine ◽  
Si Engine ◽  
Piston Mechanism ◽  
Si Engines ◽  
Ic Engines ◽  
Engine Concept

A zero dimensional model has been used to investigate the combustion performance of a four cylinder petrol engine with unconventional piston motion. The main feature of this new spark ignition (SI) engine concept is the realization of quasi-constant volume (QCV) during combustion process. Presented mechanism is designed to obtain a specific motion law which provides better fuel consumption of internal combustion (IC) engines. These advantages over standard engine are achieved through synthesis of unconventional piston mechanism. The numerical calculation was performed for several cases of different piston mechanism parameters, compression ratio and engine speed. Calculated efficiency and power diagrams are plotted and compared with performance of ordinary SI engine. The results show that combustion during quasi-constant volume has significant impact on improvement of efficiency. The main aim of this paper is to find a proper kinematics parameter of unconventional piston mechanism for most efficient heat addition in SI engines.

Impacts of combustion phasing, load, and speed on soot formation in spark-ignition engines

2019 ◽  
Vol 21 (3) ◽  
pp. 514-539
Author(s):  
Mitchell D Hageman ◽  
David A Rothamer
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Residence Time ◽  
Engine Speed ◽  
Soot Formation ◽  
Direct Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
The Impact

The premixed prevaporized engine operation method was used to study the effects of main combustion thermodynamic properties and residence time on soot formation in a spark-ignition engine. Select cases were repeated under early-injection, nearly homogeneous, spark-ignition direct-injection operation to determine if the impact of the investigated parameters was the same or if the impact of in-cylinder liquid fuel injection and the resulting heterogeneous fuel-air mixture alters the trends. The original premixed prevaporized study hypothesized that soot is more likely to form after main combustion than during the main combustion event under completely homogeneous conditions. This hypothesis was tested in this study by performing premixed prevaporized combustion phasing sweeps at equivalence ratios (Φs) of 1.35 and 1.40. Both sweeps showed low sensitivity of the particle size distribution to significant changes in peak temperature and pressure during combustion, providing supporting evidence for the original hypothesis. This information was then used to design experiments to isolate the impacts of pressure (engine load) and residence time (engine speed). A premixed prevaporized load sweep showed that particulate emissions increase as a function of load/pressure. A spark-ignition direct-injection load variation showed similar pressure dependence for cases with in-homogeneous in-cylinder fuel-air distributions. A premixed prevaporized residence time variation (performed by changing engine speed) demonstrated an increase in soot formation with increased residence time. The results for identical spark-ignition direct-injection residence-time variations suggest a trade-off in soot formation between the effects of increased mixing time and increased residence time for spark-ignition direct-injection operation. The premixed prevaporized load and speed points were each investigated using Φ sweeps to determine the critical enrichment threshold for soot formation (ΦC) and the dependence of soot formation for Φ > ΦC. The spark-ignition direct-injection investigations were performed at Φ = 0.98, such that any soot formation above the non-fuel-related baseline particle size distribution could be attributed either to mixture heterogeneity or in-cylinder fuel films.

scholarly journals Effect of ignition timing on engine characteristics of a single cylinder spark ignition engine with CNG fueled

2017 ◽  
Vol 20 (K6) ◽  
pp. 79-86
Author(s):  
Quoc Dang Tran
Keyword(s):  
Natural Gas ◽  
Thermal Efficiency ◽  
Engine Speed ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Ignition Timing ◽  
Compressed Natural Gas ◽  
Brake Thermal Efficiency ◽  
Timing System ◽  
Cng Engine

This article shows an investigated research on Compressed Natural Gas (CNG) engine with a port injection when varying ignition timing. The obtained results from simulating study have indicated that both of brake thermal efficiency and torque have a similar trend when varying ignition timing. The effect of ignition timing on the value of brake thermal efficiency is stronger in comparison with torque, however, the increase in engine speed or lambda value have to adjust the ignition timing more early. To reach the maximum break torque at each engine speed, the ignition timing should be adjusted IT = 14 - 32 bTDC, and this is also basic value to design the ignition timing system using CNG engine with port injection.

Heat Transfer Characteristics of a Spark-Ignition Engine

1980 ◽  
Vol 102 (2) ◽  
pp. 189-193 ◽  
Author(s):  
A. C. Alkidas
Keyword(s):  
Heat Flux ◽  
Engine Speed ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
High Rate ◽  
Time Of Arrival ◽  
Rate Of Increase ◽  
Peak Heat Flux ◽  
Flux Measurements ◽  
Transient Heat Flux

Transient heat flux measurements were obtained at four positions on the cylinder head of a four-stroke single-cylinder spark-ignition engine. Tests were performed for both fired and motored operation of the engine. The primary engine operational variable was engine speed. The results showed that the heat flux varies considerably with position of measurement. At fired conditions, the initial high rate of increase of heat flux at each position of measurement correlated with the calculated time of arrival of the flame at that position. Finally, as expected, the peak heat flux was found to increase with increased engine speed.

Series valve speed control system: A new type of spark ignition engine speed control system without throttle

2018 ◽  
Vol 233 (5) ◽  
pp. 1345-1351
Author(s):  
Peiyan Sun ◽  
Xiang Li ◽  
Changzhong Man ◽  
Yunbang Tang ◽  
Yi Wan
Keyword(s):  
Control System ◽  
Fuel Consumption ◽  
Fuel Economy ◽  
Power Efficiency ◽  
Engine Speed ◽  
Speed Control ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Fuel Consumption Rate ◽  
Speed Control System

Spark ignition engines perform with low power efficiency and low fuel economy for which the throttling loss is the main reason. This paper introduces a new kind of intake control system-series valve speed control system that consists of two intake valves connected in series. It is operated without throttle to reduce the engine intake loss and thereby improve fuel economy under medium- and low-load working conditions. Through experiments, we confirm that compared with the basal spark ignition engine, the spark ignition engine with series valve speed control system can reduce fuel consumption, and the maximum fuel consumption rate can be increased up to 12% at the engine speed of 3000 r/min.

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