Influence of injection strategy in a high-efficiency hydrogen direct injection engine

2011 ◽  
Vol 5 (1) ◽  
pp. 289-300 ◽  
Author(s):  
Thomas Wallner ◽  
Nicholas S. Matthias ◽  
Riccardo Scarcelli
Keyword(s):  
High Efficiency ◽  
Direct Injection ◽  
Injection Strategy ◽  
Direct Injection Engine

Effect of injection strategy on a diesel/methanol dual-fuel direct-injection engine

2021 ◽  
Vol 189 ◽  
pp. 116691
Author(s):  
Zhiyong Li ◽  
Yang Wang ◽  
Zibin Yin ◽  
Heming Geng ◽  
Rui Zhu ◽  
...  
Keyword(s):  
Direct Injection ◽  
Dual Fuel ◽  
Injection Strategy ◽  
Direct Injection Engine

Influences of the fuel injection parameters on the first-cycle firing and the combustion characteristics during the direct-start process for a gasoline direct-injection engine

2016 ◽  
Vol 231 (5) ◽  
pp. 585-599 ◽  
Author(s):  
Fangxi Xie ◽  
Yan Su ◽  
Wei Hong ◽  
Xiangyu Li ◽  
Xiaoping Li ◽  
...  
Keyword(s):  
Heat Release ◽  
Single Injection ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Injection Strategy ◽  
Fuel Mass ◽  
Direct Injection Engine ◽  
Gasoline Direct Injection Engine ◽  
Dual Injection ◽  
Start Process

The direct-start method without requiring a starter is a viable and cost-effective solution for generating a frequent and efficient restarting process when start–stop technology is used on a gasoline direct-injection engine. During the direct-start process, the first-cycle combustion characteristics play a key role in determining whether the start mode is successful or not, because the start energy is wholly derived from the in-cylinder combustion without the support of a starter motor on the gasoline direct-injection engine. However, the first-cycle fuel–air mixing and combustion characteristics during the direct-start process of a gasoline direct-injection engine are not fully understood. In this work, the influences of the injection parameters, including the delay between the injection and ignition, the excess air ratio for the single-injection strategy, the delay between the first injection and the second injection for the dual-injection strategy and the ratio of the fuel mass in the first injection to the fuel mass in the second injection for the dual-injection strategy, on the combustion pressure, the heat release rate, the accumulated heat release and the indicated work were investigated experimentally by cycle-by-cycle analysis. The results show that the optimal delay between the injection and ignition of the single-injection strategy was 200 ms as a longer delay or a shorter delay can result in a reduction in the heat released rate, the indicated work and the firing boundary. A shorter delay with the optimal injected fuel mass tended to be more beneficial to the accumulated heat released, the indicated work and the crankshaft speed. Furthermore, with increasing delay and increasing fuel ratio of the fuel mass in the first injection to the fuel mass in the second injection for the dual-injection strategy, the heat release rate, the accumulated heat release and the indicated work first increased and then decreased. The optimum delay was 10 ms and the ratios of the fuel mass in the first injection to the fuel mass in the second injection were 4/1 and 5/1 respectively under the test conditions. Additionally, the dual-injection strategy with an optimized control parameter produced a higher heat release and higher indicated work than the single-injection strategy did.

Numerical Simulations of Hollow-Cone Injection and Gasoline Compression Ignition Combustion With Naphtha Fuels

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Jihad A. Badra ◽  
Jaeheon Sim ◽  
Ahmed Elwardany ◽  
Mohammed Jaasim ◽  
Yoann Viollet ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Efficiency ◽  
Direct Injection ◽  
Compression Ignition ◽  
Hollow Cone ◽  
Direct Injection Engine ◽  
Technical Paper ◽  
Primary Reference ◽  
Partially Premixed ◽  
Compression Ignition Combustion

Gasoline compression ignition (GCI), also known as partially premixed compression ignition (PPCI) and gasoline direct injection compression ignition (GDICI), engines have been considered an attractive alternative to traditional spark ignition (SI) engines. Lean-burn combustion with the direct injection of fuel eliminates throttle losses for higher thermodynamic efficiencies, and the precise control of the mixture compositions allows better emission performance such as NOx and particulate matter (PM). Recently, low octane gasoline fuel has been identified as a viable option for the GCI engine applications due to its longer ignition delay characteristics compared to diesel and lighter evaporation compared to gasoline fuel (Chang et al., 2012, “Enabling High Efficiency Direct Injection Engine With Naphtha Fuel Through Partially Premixed Charge Compression Ignition Combustion,” SAE Technical Paper No. 2012-01-0677). The feasibility of such a concept has been demonstrated by experimental investigations at Saudi Aramco (Chang et al., 2012, “Enabling High Efficiency Direct Injection Engine With Naphtha Fuel Through Partially Premixed Charge Compression Ignition Combustion,” SAE Technical Paper No. 2012-01-0677; Chang et al., 2013, “Fuel Economy Potential of Partially Premixed Compression Ignition (PPCI) Combustion With Naphtha Fuel,” SAE Technical Paper No. 2013-01-2701). The present study aims to develop predictive capabilities for low octane gasoline fuel compression ignition (CI) engines with accurate characterization of the spray dynamics and combustion processes. Full three-dimensional simulations were conducted using converge as a basic modeling framework, using Reynolds-averaged Navier–Stokes (RANS) turbulent mixing models. An outwardly opening hollow-cone spray injector was characterized and validated against existing and new experimental data. An emphasis was made on the spray penetration characteristics. Various spray breakup and collision models have been tested and compared with the experimental data. An optimum combination has been identified and applied in the combusting GCI simulations. Linear instability sheet atomization (LISA) breakup model and modified Kelvin–Helmholtz and Rayleigh–Taylor (KH-RT) break models proved to work the best for the investigated injector. Comparisons between various existing spray models and a parametric study have been carried out to study the effects of various spray parameters. The fuel effects have been tested by using three different primary reference fuel (PRF) and toluene primary reference fuel (TPRF) surrogates. The effects of fuel temperature and chemical kinetic mechanisms have also been studied. The heating and evaporative characteristics of the low octane gasoline fuel and its PRF and TPRF surrogates were examined.

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