Nonlinear Estimation of Variables for Heat Release Calculation Using a Gradient Method

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Lianhao Yin ◽  
Gabriel Turesson ◽  
Rolf Johansson ◽  
Per Tunestål
Keyword(s):  
Heat Release ◽  
Combustion Engine ◽  
Nonlinear Least Squares ◽  
High Energy ◽  
Cylinder Pressure ◽  
Least Squares Regression ◽  
Advanced Combustion ◽  
Partially Premixed Combustion ◽  
Ci Engine ◽  
Polytropic Exponent

Advanced combustion such as the partially premixed combustion (PPC) is characterized by high energy efficiency. However, they are sensitive to the inlet condition and injection of a combustion engine. Therefore, it is essential to use combustion feedback. The accuracy of the feedback variables, derived from the cylinder pressure signal, is crucial for effective combustion feedback control. This paper proposes a nonlinear least-squares regression method to estimate the pressure offsets and variable polytropic exponent in heat release calculation automatically. The combustion feedback variables derived from the auto-tuned heat-release rate were applied to a heavy-duty compression ignition (CI) engine burning with gasoline fuel.

In-Cycle Closed Loop Control of the Fuel Injection on a 1-Cylinder Heavy Duty CI-Engine

2010 ◽  
Author(s):  
Claes-Go¨ran Zander ◽  
Per Tunesta˚l ◽  
Ola Stenla˚a˚s ◽  
Bengt Johansson
Keyword(s):  
Heat Release ◽  
Real Time ◽  
Fuel Injection ◽  
Real Time Control ◽  
Loop Control ◽  
Time Control ◽  
Ci Engine ◽  
The Difference ◽  
Proportional Controller ◽  
Polytropic Exponent

The focus of this article is on implementation of real time combustion control by using an FPGA. The feedback used for the controller is the heat release. Due to the desire to avoid using division on the FPGA an alternative way of calculating the polytropic exponent is investigated. When this method is compared against using a constant exponent it shows less fluctuations in regards to cycle to cycle variations when calculating the heat release. A dual injection strategy is used and real time control is implemented on the second fuel injection. The calculated heat release is continuously compared with a reference and then the difference is converted to a duration correction of the fuel injection. This is done by a proportional controller which is initiated after the start of the second injection. By adding a perturbation on the first fuel injection the controller is shown to compensate during the second and thereby decreasing the cycle to cycle variations.

Effect of Mahua Biodiesel Blends on the Combustion Characteristics of Direct Injection CI Engine at Various Compression Ratios

2015 ◽  
Vol 813-814 ◽  
pp. 824-829
Author(s):  
Ramani Vagesh Shangar ◽  
Venkatesan Hariram
Keyword(s):  
Heat Release ◽  
Compression Ratio ◽  
Ignition Delay ◽  
Direct Injection ◽  
Combustion Characteristics ◽  
Cylinder Pressure ◽  
Biodiesel Blends ◽  
Peak Cylinder Pressure ◽  
Ci Engine ◽  
Mahua Biodiesel

In the current study, combustion characteristics were evaluated using mahua biodiesel blends at different compression ratios on a direct injection CI engine. Non edible mahua oil was transesterified into biodiesel by two stage technique. Combustion parameters were evaluated for B5, B10 and B20 blends of mahua biodiesel with diesel and they were compared with straight diesel at compression ratios of 16, 17 and 18.Compression ratio was varied without altering the combustion chamber geometry and the static spill timing was set to 23° bTDC. Parameters like In cylinder pressure, heat release rate, rate of pressure rise and cumulative heat release were evaluated in this study at 100% engine loading conditions. Higher peak cylinder pressure and heat release was observed at higher compression ratios. The ignition delay of the blends were slightly higher compared to diesel at all CR tested. Peak cylinder pressure of the blends was slightly higher at CR 18. The ignition delay was also observed to be lower at higher compression ratio. The peak pressure was observed closer to TDC at higher compression ratios for all fuels tested.

scholarly journals Coating of diesel engine with new generation ceramic material to improve combustion and performance

2021 ◽  
Vol 25 (Spec. issue 1) ◽  
pp. 101-110
Author(s):  
Erdinc Vural ◽  
Serkan Ozel ◽  
Salih Ozer
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Bond Coat ◽  
Combustion Engine ◽  
Engine Performance ◽  
Cylinder Pressure ◽  
Engine Torque ◽  
Engine Power

In this study, piston and valve surfaces of a Diesel engine to improve exhaust emis?sion and engine performance values, NiCr with bond coat and without bond coat with Cr2O3, Al2O3+13%TiO2, Cr2O3+25%Al2O3 coatings were coated using plasma spray method. By examining the micro-structures of the coating materials, it was observed that a good coating bond is formed. In this study, unlike other coating applications, two different and proportions of specific ceramic powders were coated on the combustion chamber elements, mounted on a Diesel engine, and their effects on engine performance and emissions were tested on the engine dynamometer. For this purpose, the internal combustion engine was operated at 1400, 1700, 2000, 2300, 2600, 2900, and 3200 rpm engine speeds and engine power, engine torque, in-cylinder pressure changes and heat release rate values were recorded. In this study, the that results were obtained by comparing thermal barrier coated engine with standard engine. An increase of 14.92% in maximum engine power, 12.35% in engine torque, 13% in-cylinder pressure, heat release rate by 4.5%, and brake thermal efficiency by 10.17% was detected, while brake specific fuel consumption decreased by 14.96%.

Cylinder pressure and heat release rate analysis for hydrogen induction with injected biodiesel (pongamia pinnata) operated CI engine

2019 ◽  
Author(s):  
R. S. Karrthik ◽  
Srisaran Venkatachalam ◽  
C. Dinesh ◽  
S. Baskaran ◽  
Shanmugaraj ◽  
...  
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Pongamia Pinnata ◽  
Cylinder Pressure ◽  
Rate Analysis ◽  
Ci Engine

Effects of λ on the Combustion Characteristics of HCCI Engine Fueled with N-Butanol

2015 ◽  
Vol 1092-1093 ◽  
pp. 508-511
Author(s):  
Jia Wang Zhou ◽  
Chun Hua Zhang ◽  
Gang Li ◽  
Ye Chun Shen
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Engine ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Cylinder Pressure ◽  
Maximum Heat ◽  
Hcci Engine ◽  
Combustion Duration

The combustion characteristics of an HCCI engine fueled with n-butanol were investigated on a modified two-cylinder, four stoke diesel engine. The experiments were conducted on the HCCI engine with λ of 2.0, 2.5 and 3.0, and the intake air temperature and engine speed were kept at 140 °C and 1000rpm, respectively. Effects of λ on combustion characteristics including in-cylinder pressure rise rate, heat release rate, CA05 and combustion duration of HCCI combustion engine are discussed in details based on the recorded in-cylinder pressure. The results indicate that in-cylinder pressure and the rate of pressure rise both decrease with the increase of λ, the maximum heat release rate also decreases with the increase of λ but occurs at late crank angles. In addition, as λ increases, the combustion phasing retards and combustion duration becomes longer.

scholarly journals A comprehensive review of the influences of nanoparticles as a fuel additive in an internal combustion engine (ICE)

2020 ◽  
Vol 9 (1) ◽  
pp. 1326-1349
Author(s):  
Siti Nurul Akmal Yusof ◽  
Nor Azwadi Che Sidik ◽  
Yutaka Asako ◽  
Wan Mohd. Arif Aziz Japar ◽  
Saiful Bahri Mohamed ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Wide Spectrum ◽  
High Energy ◽  
Combustion Efficiency ◽  
Fuel Properties ◽  
Future Research ◽  
Biodiesel Fuel ◽  
Fuel Additive ◽  
Engine Combustion ◽  
Research Findings

Abstract Nanofluid is a colloidal mixture consisting of nano-sized particles dispersed in a liquid medium. It improves heat transfer properties and promotes high energy efficiency in a wide spectrum of engineering applications. In recent years, particularly in the automotive industry, the addition of nanofluid in diesel/biodiesel as an additive for ICE has become an attractive approach to promote enhanced combustion efficiency and emission reduction due to their superior thermophysical properties. Many researchers have previously demonstrated that the addition of nanoparticles in diesel/biodiesel fuel improved the overall engine combustion characteristics. As a whole, this study aims to summarize the recent research findings related to the effect of nanoparticles on the fuel properties and engine combustion efficiency. Furthermore, different types of additive blended with varying fuel properties are also compared and discussed. Lastly, the advantages and prospects of using nanofluid as an additive fuel are summarized for future research opportunities.

Optimization of Mixture Formation of Diesel Fuel in a Small CI Engine: The Effect of Water (H2O) Injection Into Intake Port

2017 ◽  
Author(s):  
Se Hun Min ◽  
Jeonghyun Park ◽  
Hyun Kyu Suh
Keyword(s):  
Water Injection ◽  
Injection Timing ◽  
Intake Port ◽  
Cylinder Pressure ◽  
Test Results ◽  
Analysis Model ◽  
Simultaneous Reduction ◽  
Effect Of Water ◽  
Rate Of Heat Release ◽  
Ci Engine

The objective of this study is to investigate the effect of water injection into intake port on the performance of small CI engine. The ECFM-3Z model was applied for the combustion analysis model, and the amount of injected water were varied 10%, 20% and 30% of injected fuel mass. The results of this work were compared in terms of cylinder pressure, rate of heat release (ROHR), and the ISNO and soot emissions. It was found that the cylinder pressure was decreased from 1.2% to 9.2% when the amount of injected water was increased from 10% to 30%. In the results, NO emission significantly decreased from about 24% to about 85% when the amount of injected water increased due to the specific heat and latent heat of water. Considering the test results, the best conditions for the simultaneous reduction of NO and soot is the BTDC 05deg of injection timing and 30% of water injection mass. It can be expected the best IMEP and ISFC characteristics.

REFRACTIVE INDEX PROFILE RECONSTRUCTION OF PLANAR WAVEGUIDE FROM ITS MODE INTENSITY USING CHARACTERISTIC MATRIX METHOD

2001 ◽  
Vol 10 (02) ◽  
pp. 169-179
Author(s):  
HENRI P. URANUS ◽  
M. O. TJIA
Keyword(s):  
Refractive Index ◽  
Intensity Distribution ◽  
Planar Waveguide ◽  
Nonlinear Least Squares ◽  
Refractive Index Profile ◽  
Characteristic Matrix ◽  
Least Squares Regression ◽  
Index Profile ◽  
Measured Intensity ◽  
Parameter Values

A method is proposed for the reconstruction of refractive index profile of planar waveguide from its fundamental mode intensity profile. The reconstruction is performed by fitting the calculated intensity distribution iteratively with the measured intensity distribution employing nonlinear least-squares regression technique. At each stage of iteration, new trial parameter values are generated and used to form a waveguide model approximated by a multilayer structure with stepwise index distribution, upon which the intensity distribution is then calculated by using the characteristic matrix technique. This method was numerically examined by using samples of either known or unknown analytic expression of the index profile.

Analysis of Incylinder Pressure and Temperature Variation in a Four-Stroke S. I. Engine Using Wiebe’s Combustion Model

2014 ◽  
Vol 984-985 ◽  
pp. 957-961
Author(s):  
Vijayashree ◽  
P. Tamil Porai ◽  
N.V. Mahalakshmi ◽  
V. Ganesan
Keyword(s):  
Heat Release ◽  
Combustion Process ◽  
Pressure Variation ◽  
Spark Ignition Engine ◽  
Working Fluid ◽  
Combustion Model ◽  
Cylinder Pressure ◽  
Crank Angle ◽  
Experimental Values ◽  
Release Model

This paper presents the modeling of in-cylinder pressure variation of a four-stroke single cylinder spark ignition engine. It uses instantaneous properties of working fluid, viz., gasoline to calculate heat release rates, needed to quantify combustion development. Cylinder pressure variation with respect to either volume or crank angle gives valuable information about the combustion process. The analysis of the pressure – volume or pressure-theta data of a engine cycle is a classical tool for engine studies. This paper aims at demonstrating the modeling of pressure variation as a function of crank angle as well as volume with the help of MATLAB program developed for this purpose. Towards this end, Woschni heat release model is used for the combustion process. The important parameter, viz., peak pressure for different compression ratios are used in the analysis. Predicted results are compared with experimental values obtained for a typical compression ratio of 8.3.

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