Difference between revisions of "Diesel and Biodiesel Lubricity"

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(2010)
 
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[[File:Einspritzduese.jpg|500px|right]]
 
[[File:Einspritzduese.jpg|500px|right]]
The hip is a complex joint system which carries much of the weight of the body. It has sophisticated interactions between cartilage, bone, synovial fluid and other connective tissue. Due to degeneration of the joint, the use of artificial hip joints has become necessary. With an increasing number of the ageing population requiring total hip replacements at a younger age (caused by both unhealthy and a more active lifestyles), it is necessary to try and improve the design and longevity of the implant. Due to the sophistication of the hip joint, and the ambition to improve the longevity, it is necessary to understand the principles of operation of the biological hip joint as well as its tribological behaviour. The purpose of the work at the University of Pretoria is focussed on:
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In modern diesel engines, the fuel also fulfils the role of lubricant in the fuel distribution system. Increasingly stringent environmental legislation forces engine manufacturers to decrease the combustion temperature to limit the amount of NOx’s and SOx’s that enter the environment. To achieve this better control of injection -and combustion processes are necessary, seeing that incomplete combustion at lower temperatures will cause soot and unburnt hydrocarbons to enter the atmosphere. The introduction of common rail diesel injection technology ensured that good control was possible, but at this stage the injection pressure is about 15 times higher than it was with conventional plunger injection. The clearances between the injection equipment have also been decreased to ensure that the pressure is not lost through the system. This has placed new demands on the lubrication properties of diesel.
* Development of an understanding of synovial joints, in particular the hip joint and its components;
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* Development of an understanding of the fundamentals of tribology and learn how it is applied to artificial hip joints;
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South African environmental legislation limits the amount of sulphur in diesel to 500ppm. The sulphur is removed through a process of hydrotreating the crude oil fractions that are used to blend diesel. The problem is that this process also removes other naturally occurring lubricity enhancing components with the sulphur. As a result of this lubricity additives need to be added to the fuel. Biodiesel (fatty acid methyl esters) have very good lubricity, but have several other limitations.
* Review current literature on the biotribology of hip joints, with focus on hip implants; and
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* Development of mathematical models describing the behaviour of synovial fluid.
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== Current/Previous projects ==
 
== Current/Previous projects ==
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=== 2008 ===
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Leenesh Moodliyar, '''Effect of Biodiesel Addition to Lubricity of Coal-Based Diesel'''<br/>
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[ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Diesel%20and%20Biodiesel%20Lubricity/2008/Leenesh%20Moodiyar%20-%20CSC410.pdf Final Year Project Report]
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=== 2010 ===
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Dean Riley, '''Characterisation of components in diesel with good lubricity with special reference to chemical and physical surface interactions'''<br/>
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[ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Diesel%20and%20Biodiesel%20Lubricity/2010/20100528_Report%28marked%29%28RileyD%29.pdf Final Year Project Report]
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Noko Meso, '''Characterisation of components in diesel with good lubricity with special reference to electrical contact resistance (ECR) measurement'''<br/>
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[ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Diesel%20and%20Biodiesel%20Lubricity/2010/20100528_Report%28marked%29%28MesoN%29.pdf Final Year Project Report]
  
=== 2006  ===
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Ryan Schultz, '''Viscosity of n-hexadecane as a function of shear rate, temperature, pressure and composition'''<br/>
Neil Pieterse, '''Development of a dynamic hip joint simulation model'''<br/>
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[ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Diesel%20and%20Biodiesel%20Lubricity/2010/20100528_Report%28marked%29%28SchultzR%29.pdf Final Year Project Report]
[ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Hip%20Tribology/PieterseN%282006%29/Dissertation%28PieterseN%29.pdf Masters Dissertation] | [ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Hip%20Tribology/PieterseN%282006%29/ Project Files] | [ftp://anonymous@ragnarok.up.ac.za/publicftp/lab/Tribology/Hip%20Tribology/PieterseN%282006%29/Matlab%20Code/ Matlab Code]
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Latest revision as of 15:20, 13 December 2010

Einspritzduese.jpg

In modern diesel engines, the fuel also fulfils the role of lubricant in the fuel distribution system. Increasingly stringent environmental legislation forces engine manufacturers to decrease the combustion temperature to limit the amount of NOx’s and SOx’s that enter the environment. To achieve this better control of injection -and combustion processes are necessary, seeing that incomplete combustion at lower temperatures will cause soot and unburnt hydrocarbons to enter the atmosphere. The introduction of common rail diesel injection technology ensured that good control was possible, but at this stage the injection pressure is about 15 times higher than it was with conventional plunger injection. The clearances between the injection equipment have also been decreased to ensure that the pressure is not lost through the system. This has placed new demands on the lubrication properties of diesel.

South African environmental legislation limits the amount of sulphur in diesel to 500ppm. The sulphur is removed through a process of hydrotreating the crude oil fractions that are used to blend diesel. The problem is that this process also removes other naturally occurring lubricity enhancing components with the sulphur. As a result of this lubricity additives need to be added to the fuel. Biodiesel (fatty acid methyl esters) have very good lubricity, but have several other limitations.

Current/Previous projects

2008

Leenesh Moodliyar, Effect of Biodiesel Addition to Lubricity of Coal-Based Diesel
Final Year Project Report

2010

Dean Riley, Characterisation of components in diesel with good lubricity with special reference to chemical and physical surface interactions
Final Year Project Report

Noko Meso, Characterisation of components in diesel with good lubricity with special reference to electrical contact resistance (ECR) measurement
Final Year Project Report

Ryan Schultz, Viscosity of n-hexadecane as a function of shear rate, temperature, pressure and composition
Final Year Project Report