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Currently, lubricated components in engines and transmissions are designed with
many different codes usually one for each component that have various
degrees of sophistication in terms of modeling different phenomena such as
elasticity, temperature, or non-Newtonian flow. The codes are proprietary to each
manufacturer, and many smaller companies have no computer codes.
many different codes usually one for each component that have various
degrees of sophistication in terms of modeling different phenomena such as
elasticity, temperature, or non-Newtonian flow. The codes are proprietary to each
manufacturer, and many smaller companies have no computer codes.
The new code should be designed with maximum flexibility to allow for future
addition of models of phenomena such as wear and scuffing, which currently are
still subjects of research. The code should model all known relevant phenomena,
including hydrodynamics, thermohydrodynamics, elastohydrodynamics, non-
Newtonian shear thinning, and effect of surface roughness on flow. The code
should be validated with classical solutions, other analytical codes, and
experimental data.
addition of models of phenomena such as wear and scuffing, which currently are
still subjects of research. The code should model all known relevant phenomena,
including hydrodynamics, thermohydrodynamics, elastohydrodynamics, non-
Newtonian shear thinning, and effect of surface roughness on flow. The code
should be validated with classical solutions, other analytical codes, and
experimental data.
It is estimated that development of this code may require up to 10 people working
for 5 years.
for 5 years.
2.
Develop advanced analytical tools and experimental methods to be used in
designing splash/mist lubrication systems for engines.
designing splash/mist lubrication systems for engines.
The piston skirt, rings, and wrist pin are lubricated by splash/mist lubrication.
Since the splash/mist lubrication process is poorly understood, there are no design
tools for this purpose, and inefficient designs result. To avoid problems related to
durability, scuffing, and noise, the lubrication system is oversized, which leads to
losses; and compromises are made in the piston and ring design, which often
result in higher friction. Some cylinders receive too much oil, resulting in excess
oil consumption and thereby excess emissions; some receive too little, resulting in
higher friction. To minimize piston noise, tighter clearances are used, which also
results in higher friction. This is significant because the piston assembly is the
main source of friction in the engine.
Since the splash/mist lubrication process is poorly understood, there are no design
tools for this purpose, and inefficient designs result. To avoid problems related to
durability, scuffing, and noise, the lubrication system is oversized, which leads to
losses; and compromises are made in the piston and ring design, which often
result in higher friction. Some cylinders receive too much oil, resulting in excess
oil consumption and thereby excess emissions; some receive too little, resulting in
higher friction. To minimize piston noise, tighter clearances are used, which also
results in higher friction. This is significant because the piston assembly is the
main source of friction in the engine.
A two-pronged approach is needed for this problem. A computer code should be
developed to calculate the amount of oil that is delivered to the various
components of the piston assembly, and advanced experimental techniques need
to be developed to validate the computations of the amount of lubricant delivered
to the cylinder bore wall, piston pin, piston skirt, and rings.
developed to calculate the amount of oil that is delivered to the various
components of the piston assembly, and advanced experimental techniques need
to be developed to validate the computations of the amount of lubricant delivered
to the cylinder bore wall, piston pin, piston skirt, and rings.
It is estimated that this project would require about 5 persons working for 5 years.
3.
Develop and demonstrate additional concepts for a controlled-lubrication
system.
system.
Current lubrication practice uses oil in excess quantities so that the least-oiled part
receives sufficient oil. This practice wastes oil by sending excess oil to other
engine parts. In addition to reducing oil consumption, solving this problem also
would have the economic benefit of increasing intervals between oil changes and
the environmental benefit of reducing emissions.
receives sufficient oil. This practice wastes oil by sending excess oil to other
engine parts. In addition to reducing oil consumption, solving this problem also
would have the economic benefit of increasing intervals between oil changes and
the environmental benefit of reducing emissions.