scholarly journals DETERMINATION OF DIESEL COMPRESSION RATIO BY RESULTS BY THE PROCESS INDEXING

2017 ◽  
pp. 44-49
Author(s):  
Alexey Valerievich Yeryganov ◽  
Roman Anatolievich Varbanets
Keyword(s):  
Compression Ratio ◽  
Pressure Rise ◽  
Analytical Form ◽  
Polytropic Index ◽  
Geometrical Parameters ◽  
Pressure Curve ◽  
Second Derivative ◽  
Compression Curve ◽  
Indicator Diagram ◽  
Crank Angle

The calculation method for determining the volume of the compression chamber and the compression ratio in the cylinder is proposed according to the diesel’s indicator diagram. The point of the compression curve is used where rate of pressure rise is maximum. At this point, the second derivative of the pressure curve along the crank angle is zero. The equation for the second derivative of the compression curve in the polytropic form was fixed. In solving this equation the polytropic index has been reduced, which enabled to derive an expression for the volume of a cylinder at the specified point in the analytical form. As a result, from the known geometrical parameters of the cylinder and the data taken from the diesel’s indicator diagram, it is possible to determine the diesel compression ratio with engineering precision, which is especially important for modern low-speed diesel engines, such as MAN, Wartsila, the documentation of which doesn’t specify this setting.

Effect of Dual Fuel Engine Parameters and Fuel Type on Engine Noise Emissions

2010 ◽  
Author(s):  
Emad Elnajjar ◽  
Mohamed Y. E. Selim ◽  
Farag Omar
Keyword(s):  
Compression Ratio ◽  
Engine Speed ◽  
Pressure Rise ◽  
Dual Fuel ◽  
Operating Parameters ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Fuel Type ◽  
Rise Rate ◽  
Crank Angle

Investigating experimentally the effects of different fuel types and engine parameters on the overall generated engine noise levels. Engine parameters such as: Engine speed, Injection timing angle, engine loading, different pilot fuel to gases fuel ratio and engine compression ratio. Engine noises due to combustion, turbulent flow and motoring were reported in this study by direct sound pressure level SPL (dB) measurements and compared to the maximum cylinder pressure rise rate with respect to the engine crank angle (dP/dθ)max. Experimental procedures conducted using a Ricardo diesel version variable compression research engine. The study was conducted for three different fuels: single diesel fuel, and dual fuel engine that uses LPG or natural gas. The study for each fuel type covered the following operating parameters range, engine speed from 20–28 rev/sec, injection timing form 20 to 45° BTDC, compression ratio from 16 to 22, load range 2 to 14 N.m, and ratio of pilot to gaseous fuel from 0 to 10%. The study reported the location (crank angle) corresponding to maximum cylinder pressure and max pressure rise rate. Results from testing dual fuel engine with varying design and operating parameters are presented and discussed. The present work reported higher SPL (dB) generated from burning a dual fuel compared to burning diesel fuel only.

An Artificial Intelligence Based Method for Performance Prediction and Inverse Design of Hydraulic Turbochargers

2020 ◽  
Author(s):  
Azam Thatte ◽  
Ganesh Vurimi ◽  
Prabhav Borate ◽  
Teymour Javaherchi
Keyword(s):  
Neural Network ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Inverse Design ◽  
Geometrical Parameters ◽  
Total Efficiency ◽  
Design Algorithm ◽  
Flow Rates ◽  
Radial Turbine ◽  
Radial Pump

Abstract A neural network based method is developed that can learn the underlying physics of hydraulic turbocharger (a radial pump coupled with a radial turbine) from a set of sparse experimental data and can predict the performance of a new turbocharger design for any given set of previously unseen operating conditions and geometric parameters. The novelty of the algorithm is that it learns the underlying physical mechanisms from a very sparse data spanning a broad range of flow rates and geometrical size brackets and uses these deeper common features recognized through a “mass-learning process” to predict the full performance curves for any given single geometry. The deep learning algorithm is able to accurately predict the key performance parameters like total efficiency of the turbocharger, its operating speed, pressure rise provided by the radial pump of the turbocharger and the shaft power produced by the radial turbine of the turbocharger for any given input combination of pump and turbine flow rates, differential pressure across the turbine and a limited set of geometrical parameters of pump and turbine impellers and volutes. Lastly, a novel method for fast inverse design of turbomachinery using a physics trained neural network and a constrained optimization algorithms is developed. The algorithm uses Nelder-Mead and Interior Point methods to find the global minimum of turbocharger design objective function in multi-dimensional space. The newly developed method is found to be very efficient in optimizing turbomachinery design problems with both equality and inequality constraints. The inverse design algorithm is able to successfully recommend an optimal combination of geometrical parameters like pump blade exit angle, pump impeller diameter, blade width, eye diameter, turbine nozzle diameter and rotational speed for a given target efficiency and head rise requirements. The preliminary results from this study indicate that it has a great potential to minimize the need for expensive 3D CFD based methods for the design of turbomachinery.

scholarly journals Modelling the effect of injection pressure on heat release parameters and nitrogen oxides in direct injection diesel engines

2014 ◽  
Vol 18 (1) ◽  
pp. 155-168 ◽  
Author(s):  
Levent Yüksek ◽  
Tarkan Sandalci ◽  
Orkun Özener ◽  
Alp Ergenc
Keyword(s):  
Nitrogen Oxides ◽  
Heat Release ◽  
Direct Injection ◽  
Pressure Rise ◽  
Injection Pressure ◽  
Premixed Combustion ◽  
Crank Angle ◽  
Cylinder Model ◽  
Combustion Phase ◽  
Rate Of Heat Release

Investigation and modelling the effect of injection pressure on heat release parameters and engine-out nitrogen oxides are the main aim of this study. A zero-dimensional and multi-zone cylinder model was developed for estimation of the effect of injection pressure rise on performance parameters of diesel engine. Double-Wiebe rate of heat release global model was used to describe fuel combustion. extended Zeldovich mechanism and partial equilibrium approach were used for modelling the formation of nitrogen oxides. Single cylinder, high pressure direct injection, electronically controlled, research engine bench was used for model calibration. 1000 and 1200 bars of fuel injection pressure were investigated while injection advance, injected fuel quantity and engine speed kept constant. The ignition delay of injected fuel reduced 0.4 crank angle with 1200 bars of injection pressure and similar effect observed in premixed combustion phase duration which reduced 0.2 crank angle. Rate of heat release of premixed combustion phase increased 1.75 % with 1200 bar injection pressure. Multi-zone cylinder model showed good agreement with experimental in-cylinder pressure data. Also it was seen that the NOx formation model greatly predicted the engine-out NOx emissions for both of the operation modes.

Study on the Combustion Characteristics of the Engine Fueled with DME-Diesel Blends

2014 ◽  
Vol 953-954 ◽  
pp. 1381-1385
Author(s):  
Wei Li ◽  
Yun Peng Li ◽  
Fan Bin Li
Keyword(s):  
Heat Release ◽  
Pressure Rise ◽  
Mechanical Efficiency ◽  
Diesel Oil ◽  
Cylinder Pressure ◽  
Mass Ratio ◽  
Combustion Duration ◽  
Crank Angle ◽  
Maximum Combustion Temperature ◽  
Stroke Engine

To further study the performance of the engine fueled with DME-diesel blends, the indicator diagrams of a two-cylinder four-stroke engine are recorded at 1700r/min and 2300r/min under different load, the heat release rate and the rate of pressure rise are calculated. The results show that: when fueled the engine with D20 blend (Mass ratio of DME and diesel oil is 2:10) and optimizing the fuel supply advance angle, the maximum cylinder pressure decreases by 10% averagely and its corresponding crank angle delays 2°CA, the maximum rate of pressure rise is relatively lowers about 20%, the beginning of heat release delays，but combustion duration do not extend, and the centroid of heat release curves is closer to TDC (Top Dead Center), maximum combustion temperature drops 70-90K. These results indicate that the mechanical efficiency will be improved and, NOx emissions and mechanical noise will be reduced when an engine fueled with DME-diesel blends.

Controlled ASSCI With Moderate Auto-Ignition for Engine Knock Suppression in a GDI Engine With High Compression Ratio

2014 ◽  
Author(s):  
Hui Liu ◽  
Zhi Wang ◽  
Jianxin Wang ◽  
Mengke Wang ◽  
Wanli Yang
Keyword(s):  
Heat Release ◽  
Compression Ratio ◽  
High Compression Ratio ◽  
Two Stage ◽  
Second Stage ◽  
High Compression ◽  
Auto Ignition ◽  
Crank Angle ◽  
Engine Knock ◽  
Gdi Engine

This paper presents an experimental study on controlled ASSCI (Assisted Spark Stratified Compression Ignition) for engine knock suppression in a GDI engine with high compression ratio. The direct injection is used for forming desired stoichiometric stratified mixture at WOT condition without turbo-charging. The engine is filled with 20% cooled external EGR and the ignition timing is maintained at MBT point. The combustion characteristics of the desired stoichiometric stratified mixture show two-stage heat release, where the first stage is caused by spark ignition and the second stage is due to moderate auto-ignition. Compared with engine knock, the second stage heat release of controlled ASSCI shows smooth pressure curve without pressure oscillation. This is due to the low energy density mixture around the cylinder wall caused by cooled external EGR. The stratified mixture could suppress knock. Fuel economy and combustion characteristics of the baseline and the controlled ASSCI combustion were compared. The baseline GDI engine reaches a maximum of 8.9 bar BMEP with BSFC of 291 g/(kWh), the controlled ASSCI combustion achieves a maximum of 8.3 bar BMEP with BSFC of 256 g/(kWh), improving the fuel economy over 12% while maintaining approximately the same power. CA50 (the crank angle of 50% heat release) of the controlled ASSCI is detected at 8.4° CA ATDC, which is 17.4° CA advanced than that of the baseline while the combustion duration of the controlled ASSCI is 52.84dG CA, 16.6° CA longer than that of the baseline caused by diluted mixture and two-stage heat release. The COV of the controlled ASSCI is 1.4%, 2.1% lower than that of the baseline. The peak pressure (Pmax) and the maximum pressure rise rate (PRRmax) of the controlled ASSCI are 59.7 bar and 2.2 bar/° CA, 22.9 bar and 1.5 bar/° CA higher than that of the baseline respectively. The crank angle of Pmax and PRRmax of the controlled ASSCI are 11° CA ATDC and −1° CA ATDC, 15.4° CA and 17.2° CA earlier than that of the baseline. The results show that controlled ASSCI with two-stage heat releases is a potential combustion strategy to suppress engine knock while achieving high efficiency of the high compression ratio gasoline engine.

CNG Car Engine Compression Ratio Optimization and Knock Simulation Analysis

2013 ◽  
Vol 341-342 ◽  
pp. 360-365
Author(s):  
Yan Qin ◽  
Yu Liu ◽  
Yuan Zhi Feng ◽  
Guang Yang Liu ◽  
Guo Dong Feng
Keyword(s):  
Compression Ratio ◽  
Simulation Analysis ◽  
Pressure Rise ◽  
Maximum Temperature ◽  
Cylinder Pressure ◽  
Full Load ◽  
Cng Engine ◽  
Set Up ◽  
Ratio Optimization

We set up one cylinder of CNG engine by using GT-Power software and the compression ratio and the knock are studied. The conclusions are as follows: when the compression ratio increases, the rate of pressure rise of acute burning period increases; The maximum cylinder pressure increases; The maximum temperature decreased slightly and after burning period the temperature increases; The critical knocking compression ratio appears at the full load of 4000rpm conditions; If we only consider it knocking or not, the engine compression ratios can change from 10 to 11.

Experimental investigation of the combustion characteristics of a biodiesel (rice-bran oil methyl ester)-fuelled direct-injection transportation diesel engine

2007 ◽  
Vol 221 (8) ◽  
pp. 921-932 ◽  
Author(s):  
S Sinha ◽  
A K Agarwal
Keyword(s):  
Diesel Engine ◽  
Methyl Ester ◽  
Vegetable Oils ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Direct Injection ◽  
Pressure Rise ◽  
Cylinder Pressure ◽  
Biodiesel Blends ◽  
Crank Angle

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.

Conversion of a Heavy-Duty Diesel Engine to Natural-Gas Spark-Ignition Operation: Test Bench Development

2019 ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin E. Dumitrescu ◽  
Hemanth Bommisetty ◽  
Christopher Ulishney
Keyword(s):  
Natural Gas ◽  
Compression Ratio ◽  
Diesel Engines ◽  
Pressure Rise ◽  
Spark Ignition ◽  
High Energy ◽  
Combustible Mixture ◽  
Stable Operation ◽  
Spark Timing ◽  
Heavy Duty Diesel

Abstract Partial conversion of the large inventory of diesel engines to natural gas (NG) spark-ignition (SI) will reduce U.S. dependence on imported petroleum and enhance national energy security. This paper describes the methodology used to retrofit such an engine as well as the experimental setup used to investigate and optimize the conversion, including engine modifications, coupled dynamometer, engine control, and data acquisition system. Low-pressure gas injectors placed upstream of the intake valve produced a homogeneous combustible mixture inside the cylinder. The final setup was verified via experiments that changed the equivalence ratio from 0.7 to 1.0 at 900 rpm, using methane as a natural gas surrogate. The results showed that despite the higher compression ratio (which increased in-cylinder pressure and temperature at spark timing compared to conventional SI engines), a high-energy spark plug was necessary to produce robust and repeatable ignition. In addition, the moderate compression ratio of the converted engine (13.3) resulted in knock-free operation at all equivalence ratios. Finally, the reliable and stable operation at the investigated conditions (COVIMEP < 1.5%) and low rate of pressure rise (< 3 bar/deg CA) support this solution for converting diesel engines to NG SI operation, at least for the conditions investigated here. The trend of engine-out emissions agreed well with existing studies, which also validated the design of the test cell for optimizing engine efficiency and sampling emissions.

Transmission of elastic disturbances caused by air shock waves in a living body

1961 ◽  
Vol 16 (3) ◽  
pp. 426-430 ◽  
Author(s):  
Carl-Johan Clemedson ◽  
Arne Jönsson
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Lead Zirconate Titanate ◽  
Technical Assistance ◽  
Great Part ◽  
Pressure Rise ◽  
Incident Shock ◽  
Incident Shock Wave ◽  
The Body ◽  
Pressure Curve

Anesthetized rabbits were exposed to air shock waves in a detonation chamber. The pressure wave patterns were recorded by means of a small lead zirconate titanate pressure transducer in the following parts of the body: at and under the skin of the side facing the charge, in the pleural sac and in the lung of that side, in the right and left ventricle of the heart, in the lung and in the pleural sac on the side opposite the charge, under the skin of that side, in the stomach, and in the skull between the bone and the brain. When the incident shock wave is propagated through the body the very steep shock front is converted so that the ascending limb of the pressure peak is much less steep, with a duration up to several hundred microseconds. The longest periods of pressure rise were found in the heart ventricles and stomach. The amplitude of the pressure curve generally diminishes as the wave passes through the body. The changes of the original shock wave are due probably in great part to the inhomogeneous structure of the animal body. Note: (With the Technical Assistance of A.-B. Sundqvist) Submitted on October 24, 1960

LPG/Gasoline Dual-Fuel Engine Design and Investigation about its Performance

2013 ◽  
Vol 333-335 ◽  
pp. 2025-2029
Author(s):  
Wei Liu ◽  
Sheng Ji Liu ◽  
Xin Kuang ◽  
Jian Sun
Keyword(s):  
Performance Test ◽  
Process Analysis ◽  
Combustion Process ◽  
Engine Performance ◽  
Dual Fuel ◽  
Pressure Curve ◽  
Engine Design ◽  
Crank Angle ◽  
The Us ◽  
Us Epa

In order to burning LPG and gasoline and dual fueled (LPG and gasoline) in the same engine, a new multi-function engine was refitted and designed based on 188F gasoline, mutative effects on the power and emission performance when burning those three kind fuel were investigated by the engine operated with the US EPA Phase-Ⅱ. Three schemes for the carburetor throat were designed. Balanced of the power and economy performance, when the diameter of the carburetor throat is 23mm, the performance was the best. By carrying engine performance test and the combustion process analysis, the results showed that: when the throttle was full opened, the power of burning only gasoline was 7.97kW, 0.5 kW and 0.28kW higher than burning LPG and dual –fuel. Burning gasoline pressure curve with the crank Angle siege area is the largest. As the emission test shows, when separately burning LPG and gasoline and dual fueled, the tendency of the excess air coefficient and the emission characteristics with the load change are same. When using LPG and dual-fuel, compared with burning gasoline, HC and NOx emission were reduced.

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