Study on Knock Characteristics of Dimethyl Ether Fueled Homogenous Charge Compression Ignition-Direct Injection Combustion Engines

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Junxing Hou ◽  
Zhenhua Wen ◽  
Jianwei Liu ◽  
Zhiqiang Jiang
Keyword(s):  
Dimethyl Ether ◽  
Direct Injection ◽  
Correlation Coefficients ◽  
Maximum Pressure ◽  
Discrete Wavelet ◽  
Pressure Amplitude ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Wavelet Energy ◽  
Four Levels

A two-cylinder diesel engine was modified for a dimethyl ether (DME) homogeneous charge compression ignition (HCCI)-direct injection (DI) engine. Knock characteristics are investigated based on in-cylinder pressure signals. The in-cylinder pressure is decomposed into four levels using discrete wavelet transform (DWT). The maximum pressure amplitudes and wavelet energy at four levels are approximately equal in normal combustion. With knock, both the maximum pressure amplitude and wavelet energy at the third level are the greatest. The correlation analysis shows that the correlation coefficients for maximum pressure amplitude and wavelet energy are quite valid for the second and third levels. It indicates that the correlation is stronger at frequencies which belong to resonant frequencies. The wavelet energy has slightly better performance than maximum pressure amplitude for identification of knock.

Experimental Study on In-Cylinder Pressure Oscillations of Homogenous Charge Compression Ignition–Direct Injection Combustion Engine Fueled With Dimethyl Ether

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Junxing Hou ◽  
Jianwei Liu ◽  
Yongqiang Wei ◽  
Zhiqiang Jiang
Keyword(s):  
Dimethyl Ether ◽  
Frequency Band ◽  
Combustion Engine ◽  
Combustion Process ◽  
Pressure Oscillation ◽  
Diffusion Combustion ◽  
Discrete Wavelet ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Pressure Oscillations

The in-cylinder pressure oscillations of a homogeneous charge compression ignition (HCCI)-DI engine fueled with dimethyl ether (DME) have been investigated using discrete wavelet transform (DWT) based on four different wavelet functions. The in-cylinder pressure is decomposed into three levels that contain three details D1, D2, and D3, and an approximation A1. In normal combustion, there are no obvious pressure impacts in three details due to smooth combustion process. The abnormal pressure oscillations occur in three details in knocking combustion, and the oscillation is most intense in D1. Its frequency band 5–10 kHz is the knock frequency band, and most high-frequency pressure oscillations and wavelet energy are in this frequency band. The pressure oscillations are located in the premixed combustion stage and diffusion combustion stage. Characteristics of in-cylinder pressure oscillations can be extracted using four wavelet functions “db4,” “db8,” “sym4,” and “sym8.” Extract abilities of four wavelet functions are different and wavelet db4 is suitable for pressure oscillation detection.

scholarly journals THE EFFECT OF DIESEL-BIODIESEL BLENDS ON THE PERFORMANCE AND EXHAUST EMISSIONS OF A DIRECT INJECTION OFF-ROAD DIESEL ENGINE

Transport ◽  
2014 ◽  
Vol 29 (4) ◽  
pp. 440-448 ◽  
Author(s):  
Tomas Mickevičius ◽  
Stasys Slavinskas ◽  
Slawomir Wierzbicki ◽  
Kamil Duda
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Bench Test ◽  
Maximum Pressure ◽  
Cylinder Pressure ◽  
Biodiesel Blends ◽  
Performance And Emission

This paper presents a comparative analysis of the diesel engine performance and emission characteristics, when operating on diesel fuel and various diesel-biodiesel (B10, B20, B40, B60) blends, at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engine D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the Heat Release Rate (HRR), maximum in-cylinder pressure and maximum pressure gradients. The influence of diesel-biodiesel blends on the Brake Specific Fuel Consumption (bsfc) and exhaust emissions was also investigated. The bench test results showed that when the engine running on blends B60 at full engine load and rated speed, the autoignition delay was 13.5% longer, in comparison with mineral diesel. Maximum cylinder pressure decreased about 1–2% when the amount of Rapeseed Methyl Ester (RME) expanded in the diesel fuel when operating at full load and 1400 min–1 speed. At rated mode, the minimum bsfc increased, when operating on biofuel blends compared to mineral diesel. The maximum brake thermal efficiency sustained at the levels from 0.3% to 6.5% lower in comparison with mineral diesel operating at full (100%) load. When the engine was running at maximum torque mode using diesel – RME fuel blends B10, B20, B40 and B60 the total emissions of nitrogen oxides decreased. At full and moderate load, the emission of carbon monoxide significantly raised as the amount of RME in fuel increased.

Evaluation of the combustion-induced noise and vibration using coherence and wavelet coherence estimates in a diesel engine

2019 ◽  
pp. 146808741987854
Author(s):  
Hossein Ahmadian ◽  
Gholamhassan Najafi ◽  
Barat Ghobadian ◽  
Seyed Reza Hassan-Beygi ◽  
Seyed Salar Hoseini
Keyword(s):  
Diesel Engine ◽  
Sound Pressure ◽  
Fuel Injection ◽  
Direct Injection ◽  
Wavelet Coherence ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Noise And Vibration ◽  
Four Levels ◽  
Wavelet Coherency

The understanding of noise generation and source identification is vital in noise control. This research was conducted to experimentally evaluate combustion-induced noise and vibration using coherence and wavelet coherence estimates. A single-cylinder direct-injection diesel engine was chosen for experimental investigation. The independent variables for conducting experiments were injection timing with five levels of 22, 27, 32 (normal), 37, and 42 crank angles before the top dead center, and also the engine torque load with four levels of 55%, 70%, 85%, and 100% of the rated value. The signals of cylinder pressure, liner acceleration, and radiated sound pressure of the test engine were measured and recorded. Then, coherency and wavelet coherency experiments were carried out between cylinder pressure and liner acceleration, cylinder pressure and sound pressure, and liner acceleration and sound pressure signals in MATLAB software. The results indicated that increasing load would increase wavelet coherency between cylinder pressure and liner acceleration signals at frequencies higher than 1 kHz. The coherent regions between cylinder pressure and sound pressure signals were mainly at frequencies higher than 1 kHz while advancing the fuel injection timing had shifted the coherency toward lower frequencies. In general, with advancing injection timing, the coherent regions between liner acceleration and sound pressure signals have appeared at broader time ranges, especially at frequencies between 100 and 500 Hz. Comparing the results of the wavelet coherency and coherency tests, we concluded that wavelet coherency is a more accurate and descriptive tool in evaluating the combustion-induced noise and vibration.

Effect of Premixed Diesel Fuel on Partial HCCI Combustion Characteristics

2014 ◽  
Vol 663 ◽  
pp. 26-33
Author(s):  
Y.H. Teoh ◽  
H.H. Masjuki ◽  
M.A. Kalam ◽  
Muhammad Afifi Amalina ◽  
H.G. How
Keyword(s):  
Diesel Fuel ◽  
Engine Speed ◽  
Direct Injection ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Compression Ignition Engine ◽  
Hcci Combustion ◽  
Light Duty ◽  
Auto Ignition ◽  
Ignition Characteristics

This study investigated the effects of premixed diesel fuel on the auto-ignition characteristics in a light duty compression ignition engine. A partial homogeneous chargecompression ignition (HCCI) engine was modified from a single cylinder, four-stroke, direct injection compression ignition engine. The partial HCCI is achieved by injecting diesel fuel into the intake port of the engine, while maintaining diesel fuel injected in cylinder for combustion triggering. The auto-ignition of diesel fuel has been studied at various premixed ratios from 0 to 0.60, under engine speed of 1600 rpm and 20Nm load. The results for performance, emissions and combustion were compared with those achieved without premixed fuel. From the heat release rate (HRR) profile which was calculated from in-cylinder pressure, it is clearly observed that two-stage and three-stage ignition were occurred in some of the cases. Besides, the increases of premixed ratio to some extent have significantly reduced in NO emission.

Experimental Research on Combustion Characteristics of PCCI–DI Engine Fueled with Dimethyl Ether

2014 ◽  
Vol 953-954 ◽  
pp. 1372-1375
Author(s):  
Wei Li ◽  
Yun Peng Li ◽  
Fan Bin Li
Keyword(s):  
Diesel Engine ◽  
Dimethyl Ether ◽  
Experimental Research ◽  
Direct Injection ◽  
Alternative Fuel ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Operating Range ◽  
Peak Cylinder Pressure ◽  
Rise Rate

The use of clean alternative fuel and new combustion mode is one of the most effective methods of further reduction of NOx and smoke emissions at diesel engine. High thermal efficiency and ultra-low NOx and PM emission of engine in HCCI combustion mode can be realized at low and medium load. However, some problems such as hard control of ignition timing and narrow operating range still exist.For the sake of expanding the operating range of HCCI (Homogeneous Charge Compression Ignition) engines and explore the scientific methods to realize the ultra-low emission with DME (Dimethyl Ether) as alternative fuel. Experimental Research on the characteristics of PCCI-DI (Partial Premixed Charge Compression Ignition – Direct Injection) combustion is carried out on a single cylinder and naturally aspirated direct injection diesel engine. Results indicate that PCCI-DI DME engine has lower peak cylinder pressure and lesser rise rate of pressure. The engine also shows up an obvious two-stage heat-release characteristic. Compared with HCCI DME engine, peak value of two heat-releases reduces, the position of the first peak almost has no change and the position of the second peak shifts to the position later than TDC (Top Dead Center).

Experimental Study on Homogeneous Charge Compression Ignition Combustion With Fuel of Dimethyl Ether and Natural Gas

2005 ◽  
Vol 128 (2) ◽  
pp. 414-420 ◽  
Author(s):  
Mingfa Yao ◽  
Zunqing Zheng ◽  
Jin Qin
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Dimethyl Ether ◽  
Flow Rate ◽  
Heat Release Rate ◽  
Release Rate ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Hcci Combustion ◽  
Peak Cylinder Pressure

The homogeneous charge compression ignition (HCCI) combustion fueled by dimethyl ether (DME) and compressed natural gas (CNG) was investigated. The experimental work was carried out on a single-cylinder diesel engine. The results show that adjusting the proportions of DME and CNG is an effective technique for controlling HCCI combustion and extending the HCCI operating range. The combustion process of HCCI with dual fuel is characterized by a distinctive two-stage heat release process. As CNG flow rate increases, the magnitude of peak cylinder pressure and the peak heat release rate in the second stage goes up. As DME flow rate increases, the peak cylinder pressure, heat release rate, and NOx emissions increase while THC and CO emissions decrease.

scholarly journals Combustion and Emissions of Gasoline Compression Ignition Engine Fuelled with Gasoline-Biodiesel Blends

2021 ◽  
Author(s):  
Yanuandri Putrasari ◽  
Ocktaeck Lim
Keyword(s):  
Combustion Engine ◽  
Direct Injection ◽  
Pressure Rise ◽  
Maximum Pressure ◽  
Compression Ignition ◽  
Biodiesel Blends ◽  
Fuel Blends ◽  
Rise Rate ◽  
Gas Recirculation ◽  
Injection Strategies

A gasoline compression ignition (GCI) engine was proposed to be the next generation internal combustion engine for gasoline. The effect of exhaust gas recirculation (EGR) and intake boosting on combustion and emissions of GCI engine fueled with gasoline-biodiesel blends by partially premixed compression ignition (PPCI) combustions are investigated in this study. Tests were conducted on a single-cylinder direct-injection CI engine, with 5% by volume proportion of biodiesel in gasoline fuel blends. Engine control parameters (EGR rate, intake boosting rate, and various injection strategies) were adjusted to investigate their influences on combustion and emissions of this GCI engine. It is found that changes in EGR rate, intake boosting pressure and injection strategies affect on ignition delay, maximum pressure rise rate and thermal efficiency which is closely tied to HC, CO, NOx and smoke emissions, respectively.

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