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Improving the performance of internal combustion engines through lubricant engineeringTaylor, Oliver January 2016 (has links)
Low friction lubricant development provides a worthwhile contribution to vehicle CO<sub>2</sub> emission reduction. Conventional low friction lubricant development focuses on empirical processes using out dated engine technology and old test methods. This strategy is inefficient and restricts the lubricant's potential. A new method proposed in the present research combines tribological simulations with rig, engine and vehicle tests. This approach provides insights undocumented until now. The contribution to CO<sub>2</sub> emission reduction from individual engine components on vehicle drive cycles that include warm-up is predicted using lubricants down to the new SAE 8 viscosity grade. A bearing model is used to design the lubricant's non Newtonian characteristics to achieve friction reduction. An isoviscous lubricant with a viscosity of 4.6 cSt is shown to achieve the minimum friction in the bearing. The research shows that by starting with lubricants having kinematic viscosities higher than this value, it is possible to improve lubricant performance by lowering viscosity index (VI), introducing shear thinning, or reducing the density and pressure viscosity coefficient. Conversely, for lubricants with lower starting viscosities it is shown that higher VI values, more shear-stable lubricants and higher densities and pressure viscosity coefficients are required. The model predicts that high oil film pressures occur in the bearing and cause significant local lubricant viscosity increase (300%), indicating that the lubricant's pressure viscosity behaviour is important here, despite the contact being conformal. Simulation and motored engine testing establishes lubricant behaviour in the piston-to-bore conjunction. This analysis identifies a poor correlation between measured and predicted values at low engine speeds. A rig-on-liner tribometer shows that this error is attributable to a deficiency in the simulation's characterisation of boundary regime friction. An oil pump test determines how a modern variable displacement oil pump (and its control system) responds to lowering viscosity. The hypothesis that low viscosity lubricants cause the parasitic load from this component to increase is disproven using this component-level rig test. Chassis dynamometer testing compares the CO<sub>2</sub> reduction performance of lubricant thermal management systems to the values achieved by reducing the viscosity grade. CO<sub>2</sub> reductions of between 0.4% and 1.0% are identified using a cold-start new European drive cycle (NEDC) with a 5W-30 preheated to 60°C and 90°C respectively. Reductions in CO<sub>2</sub> emissions between 0.4% and 1.2% are found on the NEDC by lowering the oil fill volume from 5.1 L to 2.1 L. For the unmodified case, a 3.7% reduction in CO<sub>2</sub> emissions is reported by reducing the viscosity grade from a 5W 30 to an SAE 8 in the NEDC. The performance of a novel external oil reservoir is simulated to understand its ability to retain oil temperature during the vehicle cool-down procedure. An oil temperature of 65°C at the end of the soak period (following a prior test where the oil was assumed to reach 90°C) is predicted by installing insulation to the reservoir and indicates that a viable method to achieve the CO<sub>2</sub> benefits identified through lubricant preheating tests exists. A full vehicle model combines the outputs from each of these sub-models to predict lubricant performance on the NEDC the new World-wide harmonized light duty test cycle (WLTC). This new approach provides a tool that enables next generation low friction lubricants to be developed. The model predicts that an SAE 8 lubricant can reduce CO2 emissions by 2.8% on the NEDC and 1.9% on the WLTC compared to a 5W-30. A theoretical experiment, where all lubricant related friction was deleted from the simulation, predicts that lubricant-related CO<sub>2</sub> emissions are 8.7% on the NEDC and reduce to 6.3% on the WLTC. These results indicate that the planned adoption of the WLTC in September 2017 reduces the potential contribution to CO<sub>2</sub> emission reduction from lubricants by 28%.
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PTC CREO SIMULATE ENGINE UPDATESChavan, Arun T. 06 June 2017 (has links)
This presentation is intended to inform about news of Creo Simulate.
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Designing a dynamic thermal and energy system simulation scheme for cross industry applications / W. BouwerBouwer, Werner January 2004 (has links)
The South African economy, which is largely based on heavy industry such as minerals
extraction and processing, is by nature very energy intensive. Based on the abundance of coal
resources, electricity in South Africa remains amongst the cheapest in the world. Whilst the
low electricity price has contributed towards a competitive position, it has also meant that our
existing electricity supply is often taken for granted. The economic and environmental
benefits of energy efficiency have been well documented. Worldwide, nations are beginning
to face up to the challenge of sustainable energy - in other words to alter the way that energy
is utilised so that social, environmental and economic aims of sustainable development are
supported.
South Africa as a developing nation recognises the need for energy efficiency, as it is the most
cost effective way of meeting the demands of sustainable development. South Africa, with its
unique economic, environmental and social challenges, stands to benefit the most from
implementing energy efficiency practices. The Energy Efficiency Strategy for South Africa
takes its mandate from the South African White Paper on Energy Policy. It is the first
consolidated governmental effort geared towards energy efficiency practices throughout
South Africa. The strategy allows for the immediate implementation of low-cost and no-cost
interventions, as well as those higher-cost measures with short payback periods. An initial
target has been set for an across sector energy efficiency improvement of 12% by 2014.
Thermal and energy system simulation is globally recognised as one of the most effective and
powerful tools to improve overall energy efficiency. However, because of the usual extreme
mathematical nature of most simulation algorithms, coupled with the historically academic
environment in which most simulation software is developed, valid perceptions exist that
system simulation is too time consuming and cumbersome. It is also commonly known that
system simulation is only effective in the hands of highly skilled operators, which are
specialists in their prospective fields. Through previous work done in the field, and the design
of a dynamic thermal and energy system simulation scheme for cross industry applications, it
was shown that system simulation has evolved to such an extent that these perceptions are not
valid any more.
The South African mining and commercial building industries are two of the major
consumers of electricity within South Africa. By improving energy efficiency practices within
the building and mining industry, large savings can be realised. An extensive investigation of
the literature showed that no general suitable computer simulation software for cross industry
mining and building thermal and energy system simulation could be found. Because the
heating, ventilation and air conditioning (HVAC) of buildings, closely relate to the ventilation
and cooling systems of mines, valuable knowledge from this field was used to identify the
requirements and specifications for the design of a new single cross industry dynamic
integrated thermal and energy system simulation tool.
VISUALQEC was designed and implemented to comply with the needs and requirements
identified. A new explicit system component model and explicit system simulation engine,
combined with a new improved simulation of mass flow through a system procedure,
suggested a marked improvement on overall simulation stability, efficiency and speed. The
commercial usability of the new simulation tool was verified for building applications by
doing an extensive building energy savings audit. The new simulation tool was further
verified by simulating the ventilation and cooling (VC) and underground pumping system of a
typical South African gold mine. Initial results proved satisfactory but, more case studies to
further verify the accuracy of the implemented cross industry thermal and energy system
simulation tool are needed. Because of the stable nature of the new VISUALQEC simulation
engine, the power of the simulation process can be further extended to the mathematical
optimisation of various system variables.
In conclusion, this study highlighted the need for new simulation procedures and system
designs for the successful implementation and creation of a single dynamic thermal and
energy system simulation tool for cross industry applications. South Africa should take full
advantage of the power of thermal and energy system simulation towards creating a more
energy efficient society. / Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2005.
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Designing a dynamic thermal and energy system simulation scheme for cross industry applications / W. BouwerBouwer, Werner January 2004 (has links)
The South African economy, which is largely based on heavy industry such as minerals
extraction and processing, is by nature very energy intensive. Based on the abundance of coal
resources, electricity in South Africa remains amongst the cheapest in the world. Whilst the
low electricity price has contributed towards a competitive position, it has also meant that our
existing electricity supply is often taken for granted. The economic and environmental
benefits of energy efficiency have been well documented. Worldwide, nations are beginning
to face up to the challenge of sustainable energy - in other words to alter the way that energy
is utilised so that social, environmental and economic aims of sustainable development are
supported.
South Africa as a developing nation recognises the need for energy efficiency, as it is the most
cost effective way of meeting the demands of sustainable development. South Africa, with its
unique economic, environmental and social challenges, stands to benefit the most from
implementing energy efficiency practices. The Energy Efficiency Strategy for South Africa
takes its mandate from the South African White Paper on Energy Policy. It is the first
consolidated governmental effort geared towards energy efficiency practices throughout
South Africa. The strategy allows for the immediate implementation of low-cost and no-cost
interventions, as well as those higher-cost measures with short payback periods. An initial
target has been set for an across sector energy efficiency improvement of 12% by 2014.
Thermal and energy system simulation is globally recognised as one of the most effective and
powerful tools to improve overall energy efficiency. However, because of the usual extreme
mathematical nature of most simulation algorithms, coupled with the historically academic
environment in which most simulation software is developed, valid perceptions exist that
system simulation is too time consuming and cumbersome. It is also commonly known that
system simulation is only effective in the hands of highly skilled operators, which are
specialists in their prospective fields. Through previous work done in the field, and the design
of a dynamic thermal and energy system simulation scheme for cross industry applications, it
was shown that system simulation has evolved to such an extent that these perceptions are not
valid any more.
The South African mining and commercial building industries are two of the major
consumers of electricity within South Africa. By improving energy efficiency practices within
the building and mining industry, large savings can be realised. An extensive investigation of
the literature showed that no general suitable computer simulation software for cross industry
mining and building thermal and energy system simulation could be found. Because the
heating, ventilation and air conditioning (HVAC) of buildings, closely relate to the ventilation
and cooling systems of mines, valuable knowledge from this field was used to identify the
requirements and specifications for the design of a new single cross industry dynamic
integrated thermal and energy system simulation tool.
VISUALQEC was designed and implemented to comply with the needs and requirements
identified. A new explicit system component model and explicit system simulation engine,
combined with a new improved simulation of mass flow through a system procedure,
suggested a marked improvement on overall simulation stability, efficiency and speed. The
commercial usability of the new simulation tool was verified for building applications by
doing an extensive building energy savings audit. The new simulation tool was further
verified by simulating the ventilation and cooling (VC) and underground pumping system of a
typical South African gold mine. Initial results proved satisfactory but, more case studies to
further verify the accuracy of the implemented cross industry thermal and energy system
simulation tool are needed. Because of the stable nature of the new VISUALQEC simulation
engine, the power of the simulation process can be further extended to the mathematical
optimisation of various system variables.
In conclusion, this study highlighted the need for new simulation procedures and system
designs for the successful implementation and creation of a single dynamic thermal and
energy system simulation tool for cross industry applications. South Africa should take full
advantage of the power of thermal and energy system simulation towards creating a more
energy efficient society. / Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2005.
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