Numerical studies of the effects of compression speed on the prediction for auto-ignition timing in PCCI combustion

2020 ◽  
Vol 2020.58 (0) ◽  
pp. 13a5
Author(s):  
Kaoru Miyoshi ◽  
Hiroaki Naka ◽  
Kenji Yoshida
Keyword(s):  
Ignition Timing ◽  
Numerical Studies ◽  
Compression Speed ◽  
Auto Ignition

Computational Investigation of HCCI Engine Performance With Fuel Reforming Effect on Lean Ethanol

2009 ◽  
Author(s):  
Alireza Rahbari ◽  
Bamdad Barari ◽  
Ashkan Abbasian Shirazi
Keyword(s):  
Engine Performance ◽  
Exhaust Gas ◽  
Computational Investigation ◽  
Ignition Timing ◽  
Fuel Reforming ◽  
Advanced Combustion ◽  
Auto Ignition ◽  
Gas Fuel ◽  
Start Of Combustion ◽  
Ethanol Reactions

In this study, a mechanism containing ethanol reactions is employed and the effects of exhaust gas fuel reforming on operation parameters such as ignition timing, burn duration, temperature, pressure and NOx emission are studied in which a homogeneous mixture is assumed. The results show that hydrogen in the form of reformed gas helps in lowering the intake temperature required for stable HCCI operation. It is concluded that the addition of hydrogen advances the start of combustion in the cylinder. This is a result of the lowering of the minimum intake temperature required for auto-ignition to occur during the compression stroke, resulting in advanced combustion for the same intake temperatures. The obtained results from the model are compared with the experimental data published in the literature and the comparison showed a reasonable compatibility.

scholarly journals Numerical investigation into the effect of direct fuel injection on thermal stratification in HCCI engine

2017 ◽  
Vol 169 (2) ◽  
pp. 137-140
Author(s):  
Michał GĘCA ◽  
Jacek HUNICZ ◽  
Piotr JAWORSKI
Keyword(s):  
Combustion Chamber ◽  
Thermal Stratification ◽  
Fuel Injection ◽  
Injection Timing ◽  
Ignition Timing ◽  
Hcci Engine ◽  
Auto Ignition ◽  
Negative Valve Overlap ◽  
Valve Overlap ◽  
Direct Fuel Injection

Despite the fact that HCCI engines are distinguished by mixture homogeneity, some degree of stratification always appears inside a combustion chamber. It is especially applied to residual effect engines utilizing negative valve overlap. Mixture stratification is a result of the imperfect mixing of fresh air with trapped residuals. Direct fuel injection introduces stratification as well, due to fuel vaporization. As a consequence, the temperature within the combustion chamber is uneven. Thermal stratification affects auto-ignition timing and combustion evolution in a high extent. The purpose of this study was to evaluate a degree of thermal stratification in HCCI engine utilizing negative valve overlap. Investigations were performed using three-dimensional CFD model of the combustion system, made by using AVL FIRE software. Simulations were realized for various timings of fuel injection into the cylinder. It was found that fuel injection timing had a significant effect on the thermal stratification and resulting auto-ignition timing.

Closed Loop Estimator-Controller Synthesis for a Two-Zone Controlled Auto-Ignition Engine Model

2009 ◽  
Author(s):  
Varun Tandra ◽  
Nilabh Srivastava
Keyword(s):  
Peak Pressure ◽  
Controller Synthesis ◽  
Ignition Timing ◽  
Engine Model ◽  
Exhaust Temperature ◽  
Auto Ignition ◽  
Significant Difference ◽  
Hcci Engines ◽  
Linearized Model ◽  
Variable Valve

This paper outlines the controller development for a physics-based two-zone thermo kinetic model of HCCI/CAI engine presented in the previous work. The model accounted for both temperature and concentration inhomogeneities in the cylinder, which ultimately resulted in better prediction of the combustion parameters. The discrete nonlinear model is linearized about an operating point and the resulting linearized model is used to create an effective tracking controller. The model inputs include the variable valve timings needed to effectively control peak pressure, ignition timing and exhaust temperature. Since some of the model states cannot be monitored under transient conditions, an observer was developed to estimate the states. Two controller-observer models: controller-current observer and controller-predictor observer were designed and simulated using the same engine model. A significant difference was observed between the performances of these two models. Simulation results showed that linear controller can drastically enhance the control of combustion phasing, thereby making the control of HCCI engines practical.

An experimental study of uncertainty considerations associated with predicting auto-ignition timing using the Livengood-Wu integral method

Fuel ◽  
2021 ◽  
Vol 286 ◽  
pp. 119025
Author(s):  
Ashish Shah ◽  
Song Cheng ◽  
Douglas E. Longman ◽  
S. Scott Goldsborough ◽  
Toby Rockstroh
Keyword(s):  
Experimental Study ◽  
Integral Method ◽  
Ignition Timing ◽  
Auto Ignition

Effect of Flame Propagation on the Auto-Ignition Timing in SI-CAI Hybrid Combustion (SCHC)

2014 ◽  
Author(s):  
Kang Xu ◽  
Hui Xie ◽  
Tao Chen ◽  
Minggang Wan ◽  
Hua Zhao
Keyword(s):  
Flame Propagation ◽  
Ignition Timing ◽  
Auto Ignition

Cyclic Variations of Ignition Timing in an HCCI Engine

2007 ◽  
Author(s):  
Mahdi Shahbakhti ◽  
Robert Lupul ◽  
Charles Robert Koch
Keyword(s):  
Experimental Data ◽  
Intake Manifold ◽  
Compression Ignition ◽  
Ignition Timing ◽  
Cyclic Variability ◽  
Auto Ignition ◽  
Hcci Engines ◽  
Cyclic Variations ◽  
And Control ◽  
Operating Points

Understanding the effect of modifying the properties of the engine charge on the cyclic variations of ignition timing is one essential aspect of being able to predict and control the ignition timing in Homogeneous Charge Compression Ignition (HCCI) engines. This paper investigates cyclic variability of HCCI ignition timing using the experimental data from two different engines at over 300 operating points for five different blends of iso-octane and n-heptane. Experimental results indicate that the cyclic variations of HCCI auto-ignition timing decrease with an increase in the intake manifold temperature and mixture richness, but it increases with an increase in the EGR rate.

Numerical Investigation of the Effect of Knock on Heat Transfer in a Turbocharged Spark Ignition Engine

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Arman Rostampour ◽  
Ali Nassiri Toosi
Keyword(s):  
Heat Transfer ◽  
Spark Ignition Engine ◽  
Integral Model ◽  
Dual Fuel ◽  
Average Pressure ◽  
Gas Temperature ◽  
Ignition Timing ◽  
Total Heat Transfer ◽  
Operating Cycle ◽  
Auto Ignition

This investigation deals with the EF7 (TC) engine, a dual fuel engine equipped with a turbocharger system, consequently with a high probability of knock inception. In this study, an operating cycle of the engine was simulated using KIVA-3V code. Some modifications were carried out on the KIVA method of calculating pressure in the intake port in order to simulate turbocharger pressure correctly. Auto-ignition and knock were then simulated using the auto-ignition integral model. The modified code and the simulation were verified using three different methods; in-cylinder average pressure, gas temperature of the exhaust port, and auto-ignition timing. The simulation results using the auto-ignition integral model, as compared with the experimental data, proved to be reasonably accurate. Following this validation, the effect of the knock phenomenon on the engine heat transfer through the walls was investigated. The simulations showed that the rate of heat transfer through the walls under knocking conditions is about 2.2 times higher than that under normal conditions. However, it was also shown that the total heat transfer increases about 15%.

Sign in / Sign up

Export Citation Format

Share Document