Heat Transfer in Compression-Ignition Engines: First Paper: Heat Transfer in a Quiescent Chamber Diesel Engine

1970 ◽  
Vol 185 (1) ◽  
pp. 963-975 ◽  
Author(s):  
N. D. Whitehouse
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Realistic Model ◽  
Compression Ignition ◽  
Usual Model ◽  
Mean Values ◽  
Transfer Rates ◽  
Compression Ignition Engines ◽  
Instantaneous Values ◽  
The Mean

Instantaneous and mean values of heat transfer at various positions in the combustion chamber were obtained, by means of surface thermocouples, for different loads and speeds and compared with those obtained theoretically from synthesized cycle calculations. The results show that the usual model of homogeneity in the cylinder is inadequate for heat transfer calculations. Peak rates of heat transfer when in the vicinity of a fuel spray were comparatively little dependent upon load or speed. At the periphery of the combustion chamber the mean heat transfer rates were appreciably lower than to the cylinder head and piston and the rapid rise in instantaneous values occurred appreciably later. The results all suggest the need for a more realistic model based upon the geometry and penetration of the fuel sprays.

scholarly journals Development of Electrically Aerated Stove for Pyrolyzed Briquettes

2020 ◽  
pp. 37-43
Author(s):  
O. K. Fadele ◽  
M. B. Usman ◽  
O. C. Ariyo ◽  
U. U. Emeghara ◽  
D. O. Adelani ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Burning Rate ◽  
Fuel Consumption ◽  
Power Output ◽  
Thermal Efficiency ◽  
Thermal Parameters ◽  
Specific Fuel Consumption ◽  
Mean Values ◽  
Wood Shavings ◽  
The Mean

In this study, an electrically aerated stove was developed using locally available materials. The performance of the stove was evaluated by utilizing briquettes produced from pyrolyzed jatropha shell and Eucalyptus camadulensis wood shavings. Thermal parameters such as thermal efficiency, power output, specific fuel consumption and burning rate were determined. The mean values obtained for the thermal efficiency, power output, specific fuel consumption and burning rate were 7.62 %, 1685 J/s, 0.2377 g/g, 330.90 g/hr respectively. The performance of the briquette stove was considered to not be suboptimal. The thermal efficiency can further be improved by proper insulation and adequate utilization of the heat generated in the combustion chamber.

Experimental Investigation on Combustion and Emission Characteristics of Modified Piston in an IDI Diesel Engine Fueled with Ethyl Alcohol

2014 ◽  
Vol 984-985 ◽  
pp. 873-877 ◽  
Author(s):  
M. Parthasarathy ◽  
J. Isaac Joshua Ramesh Lalvani ◽  
E. Prakash ◽  
S. Jayaraj ◽  
K. Annamalai
Keyword(s):  
Combustion Chamber ◽  
Ethyl Alcohol ◽  
Ignition Temperature ◽  
Flame Temperature ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Hot Surface Ignition ◽  
Compression Ignition Engines ◽  
Surface Ignition ◽  
Hot Surface

Compression ignition engines with ethyl alcohol as a fuel are associated with some problems. Because of ethyl alcohol has high self-ignition temperature. It can be used in compression engine by hot surface ignition method which is used to resolve the ignition of the fuel. The modification of the engine is carried out in such a way that a pre combustion chamber is designed in engine head with a provision for heat plug is made on the pre combustion chamber. A piston with squish plate is designed and thermally analyzed. The squish piston helps for attaining better homogeneous mixture than conventional piston. Thus the better combustion is obtained with the squish piston resulting with higher adiabatic flame temperature than the conventional piston. When air is inducted into the combustion chamber it is exposed to high temperature. Modifications for pure ethyl alcohol made significant improvement in thermal efficiency, torque and reduction in specific fuel consumption of an engine. The results exhibit a path toward ethyl alcohol has an effective alternative to conventional diesel engines.

Heat Transfer From an Oscillating Horizontal Wire to Water

1962 ◽  
Vol 84 (3) ◽  
pp. 251-254 ◽  
Author(s):  
F. K. Deaver ◽  
W. R. Penney ◽  
T. B. Jefferson
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Reynolds Number ◽  
Mixed Convection ◽  
Low Frequency ◽  
Mean Velocity ◽  
Transfer Rates ◽  
Low Frequency Oscillations ◽  
The Mean ◽  
Horizontal Wire

An investigation has been made to determine the effect of low frequency oscillations of relatively large amplitude on the rate of heat transfer from a small horizontal wire to water. Frequencies from 0 to 4.25 cps and amplitudes to 2.76 in. were employed. Temperature differences up to 140 deg F provided heat flux from 2000 to 300,000 Btu/hr ft2. A Reynolds number was defined based on the mean velocity of the wire, and it was shown that heat-transfer rates may be predicted by either forced, free, or mixed convection correlations depending on the relative magnitudes of Reynolds and Grashof numbers.

scholarly journals EFFECT OF CNG IN A FUEL DOSE ON THE COMBUSTION PROCESS OF A COMPRESSION-IGNITION ENGINE

Transport ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Maciej Mikulski ◽  
Sławomir Wierzbicki
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Diesel Oil ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Compression Ignition Engines ◽  
Main Component

Currently, one of the major trends in the research of contemporary combustion engines involves the potential use of alternative fuels. Considerable attention has been devoted to methane, which is the main component of Natural Gas (NG) and can also be obtained by purification of biogas. In compression-ignition engines fired with methane or Compressed Natural Gas (CNG), it is necessary to apply a dual-fuel feeding system. This paper presents the effect of the proportion of CNG in a fuel dose on the process of combustion. The recorded time series of pressure in a combustion chamber was used to determine the repeatability of the combustion process and the change of fuel compression-ignition delay in the combustion chamber. It has been showed that NG does not burn completely in a dual-fuel engine. The best conditions for combustion are ensured with higher concentrations of gaseous fuel. NG ignition does not take place simultaneously with diesel oil ignition. Moreover, if a divided dose of diesel is injected, NG ignition probably takes place at two points, as diesel oil.

scholarly journals Effects of the metals of the combustion chamber wall on methanol ignition in compression ignition engines.

1988 ◽  
Vol 54 (507) ◽  
pp. 3290-3294
Author(s):  
Zhixin HOU ◽  
Akira HARADA ◽  
Hideyuki OGAWA ◽  
Takemi CHIKAHISA ◽  
Noburu MIYAMOTO ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Chamber Wall ◽  
Compression Ignition ◽  
Compression Ignition Engines

Elemental approximate analytic procedure for the annular fin of hyperbolic profile amenable to a heat transfer course

2017 ◽  
Vol 45 (2) ◽  
pp. 170-183
Author(s):  
Antonio Campo
Keyword(s):  
Heat Transfer ◽  
Heat Equation ◽  
Undergraduate Students ◽  
Approximate Analytic Solution ◽  
Engineering Programs ◽  
Transfer Rates ◽  
Analysis And Design ◽  
Annular Fin ◽  
Constant Coefficients ◽  
The Mean

Straight or longitudinal fins of variable profile are explained in most textbooks on heat transfer, but unfortunately annular or circular fins of variable profile are not. Owing to this limitation, the present article addresses an elemental approximate analytic solution for treating the governing quasi 1-D heat equation descriptive of an annular fin of hyperbolic profile. To solve this equation approximately, usage of the mean radius of the annular fin is made. The transformed ordinary differential equation with constant coefficients is equivalent to the quasi 1-D heat equation for the straight fin of uniform profile that appears in all heat transfer textbooks. Within the framework of engineering analysis and design, the estimates of approximate temperatures and companion heat transfer rates for the annular fin of hyperbolic profile owing realistic values of the parameters give evidence of good quality and minimal errors. The transformation procedure is carried out in a step-by-step manner and can be readily comprehended by undergraduate students in mechanical engineering programs.

Second Paper: Instantaneous Heat Transfer Rates to the Cylinder Head Surface of a Small Compression-Ignition Engine

1970 ◽  
Vol 185 (1) ◽  
pp. 976-987 ◽  
Author(s):  
W. J. D. Annand ◽  
T. H. Ma
Keyword(s):  
Heat Transfer ◽  
Cylinder Head ◽  
Time Derivative ◽  
Working Fluid ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Local Conditions ◽  
Transfer Rates ◽  
Head Surface ◽  
Thin Film Thermocouple

Measurements of instantaneous heat transfer rates from the working fluid to the cylinder head of a small open-chamber, four-stroke, compression-ignition engine have been made at five points on the surface, using a new form of thin-film thermocouple. These observations demonstrate that flux magnitude and the form of flux variation during the cycle depend greatly on local conditions. Some of the observed phenomena are explained qualitatively. Finally, some results are presented of an analysis of fluxes averaged over all five locations, in terms of the bulk mean properties of the working fluid. It is shown that some compensation for the non-steady nature of the situation may be given by adding to the usual type of quasi-steady relation a term involving the time derivative of the bulk mean temperature.

Experimental Study of Natural Convective Heat Transfer From an Inclined Isothermal Square Cylinder With an Exposed Top Surface Mounted on a Flat Adiabatic Base

2010 ◽  
Author(s):  
Abdulrahim Kalendar ◽  
Patrick H. Oosthuizen ◽  
Abdulrahman Alhadhrami
Keyword(s):  
Heat Transfer ◽  
Rayleigh Number ◽  
Transfer Rate ◽  
Square Cylinder ◽  
Height Ratio ◽  
Cross Sectional ◽  
Transfer Rates ◽  
Square Cylinders ◽  
Cross Sectional Size ◽  
The Mean

Natural convective heat transfer rates from inclined cylinders with a square cross-section and which has an exposed top surface have been experimentally studied. When relatively small square cylinders with exposed top surfaces inclined at an angle to the vertical are used, the inclination angle to the vertical has, in general, a considerable effect on the magnitude of the mean heat transfer rate and on the nature of the flow over the surfaces that make up the cylinder. In the situation here considered the cylinder is mounted on a large flat essentially adiabatic surface with the other cylinder surfaces exposed to the surrounding air and with the cylinder, in general, inclined to the vertical at angles between vertically upwards and vertically downwards. The situation considered is an approximate model of that which occurs in some electrical and electronic component cooling problems. The cross-sectional size-to-height ratio of the square cylinders used in the present study was comparatively small, i.e. the square cylinders were short, the width, w, of the square cylinders being 25.4 mm and the width-to-height ratios of between 1 and 0.25 being used. One of the main aims of the present work was to determine how the cross-sectional size-to-height ratio of the square cylinder, i.e., w/h, influences the mean heat transfer rate from the cylinder at various angles of inclination between vertically upwards and vertically downwards. The heat transfer rates were determined by the transient method, this basically involving heating the model and then measuring its temperature-time variation while it cooled, the tests being carried out inside a large enclosure. Tests were carried out in air with all models at various angles of inclination to the vertical between vertically upwards and vertically downwards. The effects of w/h, Rayleigh number, Ra, and angle of inclination, φ, on the mean Nusselt number, Nu for the entire cylinder have thus been studied. The Rayleigh number, Ra, based on the cylinder height, h, was between approximately 1E4 and 5E6. The experimental results have been compared with the results obtained in an earlier numerical study.

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