HC3-1: Analysis of Influence of Crevice Volume and Cylinder Wall Temperature on HC and CO Emission from HCCI Engine by Using a Newly Developed Multi Zone Model(HC: HCCI Combustion,General Session Papers)

2008 ◽  
Vol 2008.7 (0) ◽  
pp. 305-312 ◽  
Author(s):  
Darko Kozarac ◽  
Ivan Mahalec ◽  
Zoran Lulic
Keyword(s):  
Wall Temperature ◽  
Zone Model ◽  
Cylinder Wall ◽  
General Session ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Co Emission

scholarly journals A thermo-kinetic model base study on natural gas HCCI engine response to different initial conditions

2009 ◽  
Vol 136 (1) ◽  
pp. 90-99
Author(s):  
Seyed JAZAYERI ◽  
Jahanian OMID
Keyword(s):  
Natural Gas ◽  
Initial Conditions ◽  
Chemical Species ◽  
Engine Performance ◽  
Zone Model ◽  
Model Base ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Base Study ◽  
Homogenous Charge Compression Ignition

Homogenous Charge Compression Ignition (HCCI) combustion is a promising concept to reduce engine emmisions and fuel consumption. In this paper, a thermo-kinetic single zone model is developed to study the operation characteristics of a natural gas HCCI engine. The model consists detail chemical kinetics of natural gas oxidation including 325 reactions with 53 chemical species, and is validated with experimental results of reference works. Then, the influence of parameters such as manifold temperature/pressure, and equivalance ratio on incylinder temperature/pressure trends, start of combustion and heat release rate is studied. These results are explained in detail to describe the engine performance thoroughly.

scholarly journals Simulation of predictive kinetic combustion of single cylinder HCCI engine

2020 ◽  
Author(s):  
Ibham Veza ◽  
Mohd Farid Muhamad Said ◽  
Zulkarnain Abdul Latiff ◽  
Mohd Faizal Hasan ◽  
Rifqi Irzuan Abdul Jalal ◽  
...  
Keyword(s):  
Heat Release ◽  
Air Temperature ◽  
Engine Performance ◽  
Zone Model ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Temperature Heat ◽  
Performance And Emissions ◽  
Improved Performance ◽  
Start Of Combustion

Homogeneous Charge Compression Ignition (HCCI) engine has attracted great attention due to its improved performance and emissions compared to conventional engines. It can reduce both Nitrogen Oxides (NOx) and Particulate Matter (PM) emissions simultaneously without sacrificing the engine performance. However, controlling its combustion phasing remains a major challenge due to the absence of direct control mechanism. The start of combustion is entirely initiated by the chemical reactions inside the combustion chamber, resulted from the compression of its homogeneous mixtures. Varying some critical engine parameters can play a significant role to control the combustion phasing of HCCI engine. This paper investigates the characteristics of HCCI combustion fuelled with n-heptane (C7H16) using single-zone model computational software. The model enabled the combustion object to vary from cycle to cycle. Detailed simulations were conducted to evaluate the effects of air fuel ratio (AFR), compression ratio (CR) and intake air temperature on the in-cylinder pressure and heat release rate. The simulation results showed that the single-zone model was able to predict the two-stage kinetic combustion of HCCI engine; the Low Temperature Heat Release (LTHR) and the High Temperature Heat Release (HTHR) regions. It was found that minor changes in AFR, CR and inlet air temperature led to major changes in the HCCI combustion phasing.

Understanding the Effect of Wall Conditions and Engine Geometry on Thermal Stratification and HCCI Combustion

2014 ◽  
Author(s):  
Benjamin Lawler ◽  
Satyum Joshi ◽  
Joshua Lacey ◽  
Orgun Guralp ◽  
Paul Najt ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Heat Release ◽  
Wall Temperature ◽  
Compression Ratio ◽  
Thermal Stratification ◽  
Ceramic Coatings ◽  
Combustion Efficiency ◽  
Noticeable Effect ◽  
Hcci Engine ◽  
Hcci Combustion

Thermal stratification of the unburned charge in the cylinder has a profound effect on the burn characteristics of a Homogeneous Charge Compression Ignition (HCCI) engine. Experimental data was collected in a single cylinder, gasoline-fueled, HCCI engine in order to determine the effects of combustion chamber geometry and wall conditions on thermal stratification and HCCI combustion. The study includes a wall temperature sweep and variations of piston top surface material, piston top geometry, and compression ratio. The data is processed with a traditional heat release routine, as well as a post-processing tool termed the Thermal Stratification Analysis, which calculates an unburned temperature distribution from heat release. For all of the sweeps, the 50% burned point was kept constant by varying the intake temperature. Keeping the combustion phasing constant ensures the separation of the effects of combustion phasing from the effects of wall conditions alone on HCCI and thermal stratification. The results for the wall temperature sweep show no changes to the burn characteristics once the combustion phasing has been matched with intake temperature. This result suggests that the effects of wall temperature on HCCI are mostly during the gas-exchange portion of the cycle. The ceramic coatings were able to very slightly decrease the thermal width, increase the burn rate, increase the combustion efficiency, and decrease the cumulative heat loss. The combustion efficiency increased with the lower surface area to volume ratio piston and the lower compression ratio. Lastly, the compression ratio comparison showed a noticeable effect on the temperature distribution due to the effect of pressure on ignition delay, and the variation of TDC temperature required to match combustion phasing.

A Two Zone Model of a Single Cylinder HCCI Engine for Control Applications

2008 ◽  
Author(s):  
Varun Tandra ◽  
Nilabh Srivastava
Keyword(s):  
Zone Model ◽  
Ignition Timing ◽  
Control Laws ◽  
Single Cylinder ◽  
First Law Of Thermodynamics ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Hcci Engines ◽  
Computationally Intensive ◽  
Peak Pressures

This paper presents a first step towards developing a physics-based two-zone model of a single cylinder HCCI engine. Previously control laws were derived by using single zone mathematical models of HCCI combustion; although certain multi-zone models were reported, they were found too complex and unwieldy for the development of fast and efficient controllers for HCCI engines. The present work outlines the modeling approach of a single-cylinder two-zone HCCI engine by incorporating the first law of thermodynamics and temperature and concentration inhomogeneities within the cylinder in order to better predict peak pressures and combustion timings. The results showed good conformity when compared with the computationally intensive multi-zone models. A comparative analysis between the single zone and two-zone models, in the context of predicting cylinder pressures, temperatures, ignition timing is also discussed. Moreover, the effect of external parameters such as speed, and EGR were also evaluated.

A Dynamic Model of Recompression HCCI Combustion Including Cylinder Wall Temperature

2006 ◽  
Author(s):  
Matthew J. Roelle ◽  
Nikhil Ravi ◽  
Adam F. Jungkunz ◽  
J. Christian Gerdes
Keyword(s):  
Wall Temperature ◽  
Thermal Conditions ◽  
Continuous Model ◽  
Cylinder Wall ◽  
Gas Temperature ◽  
Continuous Time Model ◽  
Time Model ◽  
Temperature Changes ◽  
Hcci Combustion ◽  
Insight Into

In a Homogeneous Charge Compression Ignition (HCCI) engine, pre-compression gas temperature and cylinder wall temperature are two of the conditions that determine combustion timing. However, they operate in completely different dynamic realms. The pre-compression gas temperature will stabilize in just a few cycles. Conversely, the cylinder wall temperature requires a minute or more. To predict combustion timing under changing thermal conditions, this paper describes a multi-state continuous-time model of HCCI combustion achieved with exhaust recompression and a discrete model of cylinder wall temperature updated once per cycle. The continuous model is necessary to capture ignition on each cycle. Wall temperature changes so little every cycle, it is only updated between combustion cycles. This scheme is investigated by comparing experimental and simulated fuel step changes, which alter residual gas temperature quickly and cylinder wall temperature slowly. Dynamic comparisons show several similar behaviors and provide insight into the physical processes.

A Fundamental Thermodynamic Study on the Effects of Engine Scale in Diesel Engines

2019 ◽  
Author(s):  
Kevin J. Burnett ◽  
Ashwani K. Gupta ◽  
Jim S. Cowart
Keyword(s):  
Heat Transfer ◽  
Surface Area ◽  
Wall Temperature ◽  
Diesel Engines ◽  
Cold Start ◽  
Cylinder Wall ◽  
Piston Speed ◽  
Heat Effects ◽  
Wide Range ◽  
Significant Difference

Abstract The Navy has a wide range of diesel engines with bore sizes varying by a factor of four. In general, diesel engines can have bore scaling over a full order of magnitude. As an engine cylinder gets larger its surface area to volume ratio reduces significantly, which in turn affects in-cylinder heat transfer. In this study, a fundamental generalized thermodynamic model of diesel engines was developed. The various key model effects were systematically analyzed along with engine bore size. Further, cylinder wall temperature was varied across a range of cold start to stabilized operating temperatures. The results of this study show that smaller bore diesel engines are always more sensitive to cold start conditions. The effect is reduced with increasing wall temperature yet smaller diesel engines have cooler end-of-compression temperatures as comparted to larger engines. The effects of engine speed, in which mean piston speed is held constant, tend to modestly reduce the differences between various size diesel engines due to non-linear heat transfer effects. When variable specific heat effects are correctly considered, end-of-compression air charge temperatures are only modestly different as a function of engine bore size. The most significant difference is the overall reduced heat transfer in larger engines due to the surface area to volume effect. A difference of a factor of three for in cylinder heat transfer relative to in-cylinder inducted air mass is predicted being much greater for the smaller engines. Higher exhaust temperatures are also characteristic of the larger bore engines. This allows more combustion work to be delivered to the piston with a correspondingly higher thermal efficiency for larger diesel engines. Future work will evaluate fuel effects on varying bore size.

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