Phasing cylinder pressure to crank angle in a direct injection diesel engine, by simulation of compression curve and elaboration of measured pressure data

1991 ◽  
Vol 57 (3) ◽  
pp. 87-95 ◽  
Author(s):  
Dimitros A. Kouremenos ◽  
Constantine D. Rakopoulos ◽  
Constantine G. Kotsos
Author(s):  
Seungsuk Oh ◽  
Junsoo Kim ◽  
Byounggul Oh ◽  
Kangyoon Lee ◽  
Myoungho Sunwoo

An in-cylinder pressure-based control method is capable of improving engine performance, as well as reducing harmful emissions. However, this method is difficult to be implemented in a conventional engine management system due to the excessive data acquisition and long computation time. In this study, we propose a real-time indicated mean effective pressure (IMEP) estimation method using cylinder pressure in a common-rail direct injection diesel engine. In this method, difference pressure integral (DPI) was applied to the estimation. The DPI requires only 180 pressure data points during one engine cycle from top dead center to bottom dead center when pressure data are captured at every crank angle. Therefore, the IMEP can be estimated in real time. To further reduce the computational load, the IMEP was also estimated using DPI at 2 deg, 3 deg, and 4 deg crank angle resolutions. Furthermore, based on the estimated IMEP, we controlled IMEP using a radial basis function network and linear feedback controller. As a result of the study, successful estimation and control were demonstrated through engine experiments.


Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3478 ◽  
Author(s):  
Tomasz Skrzek ◽  
Mirosław Rucki ◽  
Krzysztof Górski ◽  
Jonas Matijošius ◽  
Dalibor Barta ◽  
...  

This paper addresses the issue of metrological accuracy of instantaneous in-cylinder pressure measurement in a diesel engine test bed. In studies, the central unit has been the single-cylinder AVL 5402 engine. The pressure measurement was performed with a sensor designed for thermodynamic analysis, and the results were related to the crank angle, where two rotations corresponding to the four-stroke working cycle were denoted as angles between −360° and +360°. The novelty of this paper is the proposition of how to perform a type A uncertainty estimation of the in-cylinder pressure measurement and to assess its repeatability. It was demonstrated that repeatability of the measurement during the ignition process was difficult to estimate because of the phenomena that cannot ensure the repeatability conditions. To solve the problem, two methods were proposed. In one method, the pressure was measured in the subsequent cycles immediately after the ignition was turned off, and in another method, the engine was driven by a starter. The latter method provided maximal pressure values much lower than during usual tests. The obtained repeatability of measured pressure was %EV = 0.4%, which proved high capability of the evaluated measurement system.


2005 ◽  
Author(s):  
Olivier Grondin ◽  
Christophe Letellier ◽  
Jean Maquet ◽  
Luis Antonio Aguirre ◽  
Frédéric Dionnet

Author(s):  
S Sinha ◽  
A K Agarwal

Increased environmental awareness and depletion of fossil petroleum resources are driving industry to develop alternative fuels that are environmentally more acceptable. Transesterified vegetable oil derivatives called ‘biodiesel’ appear to be the most convenient way of utilizing bio-origin vegetable oils as substitute fuels in diesel engines. The methyl esters of vegetable oils do not require significant modification of existing engine hardware. Previous research has shown that biodiesel has comparable performance and lower brake specific fuel consumption than diesel with significant reduction in emissions of CO, hydrocarbons (HC), and smoke but slightly increased NO x emissions. In the present experimental research work, methyl ester of rice-bran oil is derived through transesterification of rice-bran oil using methanol in the presence of sodium hydroxide (NaOH) catalyst. Experimental investigations have been carried out to examine the combustion characteristics in a direct injection transportation diesel engine running with diesel, biodiesel (rice-bran oil methyl ester), and its blends with diesel. Engine tests were performed at different engine loads ranging from no load to rated (100 per cent) load at two different engine speeds (1400 and 1800 r/min). A careful analysis of the cylinder pressure rise, heat release, and other combustion parameters such as the cylinder peak combustion pressure, rate of pressure rise, crank angle at which peak pressure occurs, rate of pressure rise, and mass burning rates was carried out. All test fuels exhibited similar combustion stages as diesel; however, biodiesel blends showed an earlier start of combustion and lower heat release during premixed combustion phase at all engine load-speed combinations. The maximum cylinder pressure reduces as the fraction of biodiesel increases in the blend and, at higher engine loads, the crank angle position of the peak cylinder pressure for biodiesel blends shifted away from the top dead centre in comparison with baseline diesel data. The maximum rate of pressure rise was found to be higher for diesel at higher engine loads; however, combustion duration was higher for biodiesel blends.


Author(s):  
Joseph Gerard T. Reyes ◽  
Edwin N. Quiros

The combustion duration in an internal combustion engine is the period bounded by the engine crank angles known as the start of combustion (SOC) and end of combustion (EOC), respectively. This period is essential in analysis of combustion for the such as the production of exhaust emissions. For compression-ignition engines, such as diesel engines, several approaches were developed in order to approximate the crank angle for the start of combustion. These approaches utilized the curves of measured in-cylinder pressures and determining by inspection the crank angle where the slope is steep following a minimum value, indicating that combustion has begun. These pressure data may also be utilized together with the corresponding cylinder volumes to generate the apparent heat release rate (AHRR), which shows the trend of heat transfer of the gases enclosed in the engine cylinder. The start of combustion is then determined at the point where the value of the AHRR is minimum and followed by a rapid increase in value, whereas the EOC is at the crank angle where the AHRR attains a flat slope prior to the exhaust stroke of the engine. To verify the location of the SOC, injection line pressures and fuel injection timing are also used. This method was applied in an engine test bench using a four-cylinder common-rail direct injection diesel engine with a pressure transducer installed in the first cylinder. Injector line pressures and fuel injector voltage signals per engine cycle were also recorded and plotted. By analyzing the trends of this curves in line with the generated AHRR curves, the SOC may be readily determined.


Author(s):  
Sukhbir Singh Khaira ◽  
Amandeep Singh ◽  
Marcis Jansons

Acoustic noise emitted by a diesel engine generally exceeds that produced by its spark-ignited equivalent and may hinder the acceptance of this more efficient engine type in the passenger car market (1). This work characterizes the combustion noise from a single-cylinder direct-injection diesel engine and examines the degree to which it may be minimized by optimal choice of injection parameters. The relative contribution of motoring, combustion and resonance components to overall engine noise are determined by decomposition of in-cylinder pressure traces over a range of load, injection pressure and start of injection. The frequency spectra of microphone signals recorded external to the engine are correlated with those of in-cylinder pressure traces. Short Time Fourier Transformation (STFT) is applied to cylinder pressure traces to reveal the occurrence of motoring, combustion noise and resonance in the frequency domain over the course of the engine cycle. Loudness is found to increase with enhanced resonance, in proportion to the rate of cylinder pressure rise and under conditions of high injection pressure, load and advanced injection timing.


2019 ◽  
Vol 130 ◽  
pp. 01036
Author(s):  
Willyanto Anggono ◽  
Wataru Ikoma ◽  
Haoyu Chen ◽  
Zhiyuan Liu ◽  
Mitsuhisa Ichiyanagi ◽  
...  

The diesel engines are superior in terms of power efficiency and fuel economy compared to gasoline engines. In order to optimize the performance of direct injection diesel engine, the effect of various intake pressure (boost pressure) from supercharging direct injection diesel engine was studied at various engine rotation. A single cylinder direct injection diesel engine was used in this experiment. The bore diameter of the engine used was set to 85 mm, the stroke length was set to 96.9 mm, and the compression ratio was set to 16.3. The variation of engine rotation started from 800 rpm to 2 000 rpm with 400 rpm increment. The variation of boost pressure is bounded from 0 kPa boost pressure (naturally aspirated) to the maximum of 60 kPa boost pressure with 20 kPa boost pressure increment. The performance of the engine is evaluated in terms of in-cylinder pressure and heat release rate as the most important performance characteristics of the diesel engine. The in-cylinder pressure and heat release rate of direct injection diesel engine are increased with the elevation of boost pressure at various engine rotation. The raise of engine rotation resulted in the decrease of maximum in-cylinder pressure and heat release rate.


Author(s):  
D J Timoney ◽  
J M Desantes ◽  
L Hernández ◽  
C M Lyons

Continued legislative pressure to reduce NO x emissions from diesel engine combustion systems generates a desire for cycle-by-cycle emissions data, with a view to their use in a feedback control strategy, perhaps in conjunction with an exhaust catalytic reactor. While NO x sensors that provide fast, robust, reliable, and continuous measurements in a diesel exhaust at a reasonable price are currently the subject of much development, the present work focuses on an indirect approach. This has led to the development of a semi-empirical model that can be used to estimate NO x emissions, based on more easily measured input data, primarily in the form of instantaneous in-cylinder pressure as a function of crank angle. The model computations are based on fundamental thermodynamic principles, but key empirical constants have been derived with the aid of statistical techniques. The approach taken relied on the availability of an extensive bank of experimental data from three different designs of direct injection diesel engine, each utilizing common rail type fuel injection systems and, in some cases, with the use of multiple injections per cycle.


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