INFLUENCE OF COMPRESSION RATIO ON COMBUSTION, TURBULENCE, SWIRLS INTO MODEL COMBUSTION CHAMBER OF SI ENGINES

2015 ◽  
Vol 22 (4) ◽  
pp. 179-186
Author(s):  
Tomasz Leżański ◽  
Janusz Sęczyk ◽  
Piotr Wolański
Keyword(s):  
Combustion Chamber ◽  
Compression Ratio ◽  
Si Engines ◽  
Combustion Turbulence

DEVELOPMENT OF THE COMBUSTION CHAMBER OF GAS ENGINE, CONVERTED ON THE BASIS OF DIESELS D-120 OR D-144 ENGINES TO WORK FOR ON LIQUEFIED PETROLEUM GAS

2019 ◽  
pp. 2-8
Author(s):  
Serhii Kovalov
Keyword(s):  
Combustion Chamber ◽  
Compression Ratio ◽  
Diesel Engines ◽  
Combustion Engine ◽  
Motor Fuel ◽  
Liquefied Petroleum Gas ◽  
Gas Engine ◽  
Chamber Volume ◽  
Motor Fuels ◽  
Dynamic Cycle

The expediency of using vehicles of liquefied petroleum gas as a motor fuel, as com-pared with traditional liquid motor fuels, in particular with diesel fuel, is shown. The advantages of converting diesel engines into gas ICEs with forced ignition with respect to conversion into gas diesel engines are substantiated. The analysis of methods for reducing the compression ratio in diesel engines when converting them into gas ICEs with forced ignition has been carried out. It is shown that for converting diesel engines into gas ICEs with forced ignition, it is advisable to use the Otto thermo-dynamic cycle with a decrease in the geometric degree of compression. The choice is grounded and an open combustion chamber in the form of an inverted axisymmetric “truncated cone” is developed. The proposed shape of the combustion chamber of a gas internal combustion engine for operation in the LPG reduces the geometric compression ratio of D-120 and D-144 diesel engines with an unseparated spherical combustion chamber, which reduces the geometric compression ratio from ε = 16,5 to ε = 9,4. The developed form of the combustion chamber allows the new diesel pistons or diesel pistons which are in operation to be in operation to be refined, instead of making special new gas pistons and to reduce the geometric compression ratio of diesel engines only by increasing the combustion chamber volume in the piston. This method of reducing the geometric degree of compression using conventional lathes is the most technologically advanced and cheap, as well as the least time consuming. Keywords: self-propelled chassis SSh-2540, wheeled tractors, diesel engines D-120 and D-144, gas engine with forced ignition, liquefied petroleum gas (LPG), compression ratio of the internal com-bustion engine, vehicles operating in the LPG.

scholarly journals Phenomenological model for determining velocity field of LPG jet in combustion chamber of direct injection S.I. engine

2004 ◽  
Vol 26 (2) ◽  
pp. 83-92
Author(s):  
Bui Van Ga ◽  
Phung Xuan Tho ◽  
Nhan Hong Quang ◽  
Nguyen Huu Huong
Keyword(s):  
Combustion Chamber ◽  
Phenomenological Model ◽  
Direct Injection ◽  
Spark Ignition ◽  
Velocity Profiles ◽  
Gas Jet ◽  
Liquefied Petroleum Gas ◽  
Si Engine ◽  
Si Engines ◽  
Stratified Combustion

A phenomenological model has been established to predict the velocity distribution of LPG (Liquefied Petroleum Gas) jet in combustion chamber of spark ignition (SI) engine. A shaped coefficient \(\beta\) governing the similarity of velocity profiles of LPG jets has been defined based on the theoretical and experimental analyses of turbulent diffusion jets. The results show that \(\beta\) is constant for steady jet but it is not the case for unsteady one. The model will enable us to calculate the velocity profiles of LPG jet after ending injection. This is necessary for research of stratified combustion in direct injection LPG SI engines.

Thermal Loading of a Petrol Engine

1973 ◽  
Vol 187 (1) ◽  
pp. 561-573 ◽  
Author(s):  
C. C. J. French ◽  
K. A. Atkins
Keyword(s):  
Combustion Chamber ◽  
Compression Ratio ◽  
High Speed ◽  
Thermal Loading ◽  
Cylinder Liner ◽  
Heat Fluxes ◽  
Exhaust Valve ◽  
Petrol Engine ◽  
Coolant Temperature ◽  
Order Effects

This paper reports the results of an investigation into the thermal loading of a modern 1·975 1, four-cylinder petrol engine operating at engine speeds of up to 100 rev/s. The effects of engine speed and load, mixture strength, ignition advance, compression ratio, coolant temperature and pressure, antifreeze, detonation, olefin content of fuel, and a piston modification on the local heat fluxes and metal temperatures have been determined and the maximum levels established. The methods of temperature measurement were fixed and traversing thermocouples for the cylinder head and liner, fixed thermocouples for the valve seats and spark plug, disappearing-filament optimal pyrometer and hardness recovery for the exhaust valve, differential thermocouples for the gross heat losses, and intermittent-contact fixed thermocouples for the piston. The greatest heat fluxes occurred at the centre of the combustion chamber, in the valve bridge and exhaust-valve seat region, and decreased towards the outside of the combustion chamber and down the cylinder liner. For the form of combustion chamber investigated the heat flux varied as the 0·6 power of the gross fuel consumption and the operating variables generally gave only second-order effects. The piston temperature is fairly sensitive to ignition advance, compression ratio, and high-speed detonation.

Combustion Chamber Deposits and PAH Formation in SI Engines Fueled by Producer Gas from Biomass Gasification

2003 ◽  
Author(s):  
Jesper Ahrenfeldt ◽  
Ulrik Henriksen ◽  
Jesper Schramm ◽  
Torben K. Jensen ◽  
Helge Egsgaard
Keyword(s):  
Combustion Chamber ◽  
Biomass Gasification ◽  
Producer Gas ◽  
Si Engines ◽  
Combustion Chamber Deposits

Characterization of Tumble Motion in SI Engines: A New Parameter

2002 ◽  
Author(s):  
Pramod S. Mehta ◽  
M. Achuth
Keyword(s):  
Life Span ◽  
Combustion Chamber ◽  
Flow Analysis ◽  
Combustion Process ◽  
Operating Conditions ◽  
Mean Flow ◽  
Detailed Mechanism ◽  
Engine Combustion ◽  
Si Engines

A well-timed turbulence due to tumble in SI engines is found to be of substantial benefit to the engine combustion process. A mean flow analysis of tumble motion in conjunction with k-ε turbulence model has been developed to provide a detailed mechanism for turbulence enhancement due to tumble. Considering that the tumble phenomenon is highly geometry dependant, an attempt is made to relate tumble-generated turbulence to the parameters relating to intake conditions and combustion chamber geometry. Finally, a new parameter ‘vortex life span’ has been proposed to characterize tumble and its turbulence, which globally encompasses intake and combustion chamber related features. The sensitivity of this parameter is demonstrated at various operating conditions. It is found that the ‘vortex life span’ has an inverse relationship with commonly measured BDC tumble ratio and is more sensitive to the chamber geometry effects.

Influence of combustion chamber geometry and compression ratio on the main parameters of a diesel aircraft engine

2017 ◽  
Vol 60 (2) ◽  
pp. 219-222
Author(s):  
V. M. Gureev ◽  
A. Kh. Khairullin ◽  
F. A. Varlamov ◽  
I. F. Gumerov ◽  
R. Kh. Khafizov
Keyword(s):  
Combustion Chamber ◽  
Compression Ratio ◽  
Aircraft Engine

Alternative Multi-Nutating-Disk Engine Configurations for Diverse Applications

2001 ◽  
Author(s):  
T. Korakianitis ◽  
L. Meyer ◽  
M. Boruta ◽  
H. E. McCormick
Keyword(s):  
Combustion Chamber ◽  
Compression Ratio ◽  
Gas Turbines ◽  
Power Efficiency ◽  
Normal Operation ◽  
Maximum Efficiency ◽  
Performance Potential ◽  
Variable Compression Ratio ◽  
External Combustion ◽  
Variable Compression

The nutating engine is a new type of internal combustion engine with distinct advantages over conventional piston engines and gas turbines in small power ranges. The engine’s unique arrangement flexibility allows several alternative disk and shaft configurations, each selected for a different application. Variations in cycle temperature ratio and compression ratio during normal operation enable the engine to effectively become a variable-cycle engine, allowing significant flexibility for maximum efficiency or power or other optimizing function for on-ground stationary or for airborne applications. In its basic configuration the core of the engine is a nutating non-rotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk “nutates”, performs a wobbling motion without rotating around its axis. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. A companion paper examines the performance potential of the one-disk engine. This paper examines alternative engine configurations. The external combustion chamber enables the engine to operate on a variable compression ratio cycle. In addition, separate disks of unequal size are used for intake and expansion, resulting in distinct and significant power, efficiency, fuel flexibility, and arrangement advantages over conventional piston engines, over gas turbines, and over the basic nutating-engine configuration. The performance of these arrangements is examined for: on-ground power, on ground efficiency, (auxiliary power, automotive); and for small and light airframe applications for flight Mach numbers from 0 to 1 and altitudes from 0 to 20 km. This publication is the original presentation of the performance potential of several alternative configurations of the basic engine, such as multi-disk arrangements, combustion and exhaust disks of different size, and variable-compression ratio (variable cycle) configurations.

Phenomenological Analysis of the Combustion of Gaseous Fuels to Measure the Fuel's Energy Quality and Availability to Produce Work in Si Engines, Part 2

2021 ◽  
Author(s):  
Juan Pablo Gomez Montoya ◽  
Andres Amell
Keyword(s):  
Compression Ratio ◽  
Laminar Flame ◽  
Flame Temperature ◽  
Electrical Energy ◽  
Gaseous Fuels ◽  
Diesel Fuels ◽  
Fuel Blends ◽  
Si Engines ◽  
High Turbulence ◽  
Methane Number

Abstract A novel methodology is proposed to evaluate fuel´s performance in spark ignition (SI) engines based on the fuel´s energy quality and availability to produce work. Experiments used a diesel engine with a high compression ratio (CR), modified by SI operation, and using interchangeable pistons. The interchangeable pistons allowed for the generation of varying degrees of turbulence during combustion, ranging from middle to high turbulence. The generating efficiency (ηq), and the maximum electrical energy (EEmax) were measured at the knocking threshold (KT). A cooperative fuel research (CFR) engine operating at the KT was also used to measure the methane number (MN), and critical compression ratio (CCR) for gaseous fuels. Fuels with MNs ranging from 37 to 140 were used: two biogases, methane, propane, and five fuel blends of biogas with methane/propane and hydrogen. Results from both engines are linked at the KT to determine correlations between fuel´s physicochemical properties and the knocking phenomenon. Certain correlations between knocking and fuel properties were experimentally determined: energy density (ED), laminar flame speed (SL), adiabatic flame temperature (Tad), heat capacity ratio (γ), and hydrogen/carbon (H/C) ratio. Based on the results, a mathematical methodology for estimating EEmax and ηq in terms of ED, SL, Tad, γ, H/C, and MN is presented. These equations were derived from the classical maximum thermal efficiency for SI engines given by the Otto cycle efficiency (ηOtto). Fuels with MN > 97 got higher EEmax, and ηq than propane, and diesel fuels.

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