In Situ Control of Lubricant Properties for Reduction of Power Cylinder Friction Through Thermal Barrier Coating PDF Download
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Author: Mark Allen Molewyk
Publisher:
ISBN:
Category :
Languages : en
Pages : 62
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Book Description
Lowering lubricant viscosity to reduce friction generally carries a side effect of increased metal-metal contact in mixed or boundary lubrication, for example near top ring reversal along the engine cylinder liner. A strategy to reduce viscosity without increased metal-metal contact involves controlling the local viscosity away from top-ring-reversal locations. This paper discusses the implementation of insulation or thermal barrier coating (TBC) as a means of reducing local oil viscosity and power cylinder friction in internal combustion engines with minimal side effects of increased wear. TBC is selectively applied to the outside diameter of the cylinder liner to increase the local oil temperature along the liner. Due to the temperature dependence of oil viscosity, the increase in temperature from insulation results in a decrease in the local oil viscosity. The control of local viscosity through TBC targets areas of high hydrodynamic power losses mid-stroke while avoiding an increase in boundary friction near ring reversal. If temperatures near ring reversal remain unaltered, the expected result is the same oil viscosity, boundary friction, and wear rate near TDC as that of a non-insulated liner. In order to calculate the frictional benefit of insulating the cylinder liner, an in-cylinder heat transfer model predicts the temperatures along the liner. The local oil temperatures and engine performance parameters are then applied to a ring pack simulation to calculate the contributions to hydrodynamic and boundary friction power loss. The BsFC and wear rate results are then compared to baseline simulation data for TBC performance metrics. The results show the TBC insulated liner maintains adequate viscosity and film thickness near TDC for wear protection in the ring, while decreasing a significant portion of hydrodynamic for friction power loss in the mid-stroke. For the case studied, TBC offers a 0.7% BsFC improvement from the reduction in power cylinder friction with no increase in the wear rate of the ring pack.
Author: Mark Allen Molewyk
Publisher:
ISBN:
Category :
Languages : en
Pages : 62
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Book Description
Lowering lubricant viscosity to reduce friction generally carries a side effect of increased metal-metal contact in mixed or boundary lubrication, for example near top ring reversal along the engine cylinder liner. A strategy to reduce viscosity without increased metal-metal contact involves controlling the local viscosity away from top-ring-reversal locations. This paper discusses the implementation of insulation or thermal barrier coating (TBC) as a means of reducing local oil viscosity and power cylinder friction in internal combustion engines with minimal side effects of increased wear. TBC is selectively applied to the outside diameter of the cylinder liner to increase the local oil temperature along the liner. Due to the temperature dependence of oil viscosity, the increase in temperature from insulation results in a decrease in the local oil viscosity. The control of local viscosity through TBC targets areas of high hydrodynamic power losses mid-stroke while avoiding an increase in boundary friction near ring reversal. If temperatures near ring reversal remain unaltered, the expected result is the same oil viscosity, boundary friction, and wear rate near TDC as that of a non-insulated liner. In order to calculate the frictional benefit of insulating the cylinder liner, an in-cylinder heat transfer model predicts the temperatures along the liner. The local oil temperatures and engine performance parameters are then applied to a ring pack simulation to calculate the contributions to hydrodynamic and boundary friction power loss. The BsFC and wear rate results are then compared to baseline simulation data for TBC performance metrics. The results show the TBC insulated liner maintains adequate viscosity and film thickness near TDC for wear protection in the ring, while decreasing a significant portion of hydrodynamic for friction power loss in the mid-stroke. For the case studied, TBC offers a 0.7% BsFC improvement from the reduction in power cylinder friction with no increase in the wear rate of the ring pack.
Author: Michael Anderson Marr
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Surface temperature and heat flux measurements were made in a single cylinder SI engine piston when uncoated and with two different surface coatings: a metal TBC and YSZ. A new thermocouple was developed to accurately measure surface temperatures. The engine was operated in a standard full load mode and a knock promoting mode featuring heated intake air and advanced spark timing. Cylinder pressures were measured to quantify knock. It was found that average heat flux into the piston substrate was 33 % higher with the metal TBC and unchanged with the YSZ relative to the uncoated surface. The increase with the metal TBC was attributed to its surface roughness. However, the metal TBC and YSZ reduced peak heat flux by 69 and 77 %, respectively. Both the metal TBC and YSZ reduced knock compared to the uncoated surface. After testing, the metal TBC was undamaged and the YSZ was slightly chipped.
Author: NA NA
Publisher: Springer
ISBN: 1349815500
Category : Technology & Engineering
Languages : en
Pages : 136
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Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12
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Book Description
Amorphous carbon coatings with very low friction properties were recently developed at Argonne National Laboratory. These coatings have shown good promise in mitigating excessive wear and scuffing problems associated with low-lubricity diesel fuels. To reduce the negative effect of sulfur and other lubricant additives in poisoning the after-treatment catalyst, a lubricant formulation with a low level of sulfur may be needed. Exclusion of proven sulfur-containing extreme pressure (EP) and antiwear additives from oils will require other measures to ensure durability of critical lubricated components. The low-friction carbon coating has the potential for such applications. In the present study, we evaluated the friction and wear attributes of three variations of the coating under a boundary lubrication regime. Tests were conducted with both synthetic and mineral oil lubricants using a ball-on-flat contact configuration in reciprocating sliding. Although the three variations of the coating provided modest reductions in friction coefficient, they all reduced wear substantially compared to an uncoated surface. The degradation mode of oxidative wear on the uncoated surface was replaced by a polishing wear mode on the coated surfaces.
Author: National Aeronautics and Space Adm Nasa
Publisher:
ISBN: 9781724036841
Category :
Languages : en
Pages : 32
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Book Description
Ceramic thermal barrier coatings (TBCS) have been developed for advanced gas turbine and diesel engine applications to improve engine reliability and fuel efficiency. However, durability issues of these thermal barrier coatings under high temperature cyclic conditions are still of major concern. The coating failure depends not only on the coating, but also on the ceramic sintering/creep and bond coat oxidation under the operating conditions. Novel test approaches have been established to obtain critical thermomechanical and thermophysical properties of the coating systems under near-realistic transient and steady state temperature and stress gradients encountered in advanced engine systems. This paper presents detailed experimental and modeling results describing processes occurring in the ZrO2-Y2O3 thermal barrier coating systems, thus providing a framework for developing strategies to manage ceramic coating architecture, microstructure and properties. Zhu, Dongming and Miller, Robert A. Glenn Research Center NASA/TM-1999-209453, NAS 1.15:209453, E-11948
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 390
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Book Description
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723457784
Category :
Languages : en
Pages : 144
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Book Description
An engineered thick thermal barrier coating consisting of multiple layers of zirconia and CoCrAlY with a zirconia top layer and having a system thermal conductance less than 410 w/m(exp 2)K exceeded the 100 hour engine durability goals set forth in this program. The thermal barrier coatings were intact at the test conclusion. Back to back single cylinder research engine tests were conducted with watercooled, metal hardware and oil-cooled, thermal barrier coating insulated hardware to determine apparent heat release and fuel economy. Apparent heat release data revealed that the insulated engine had a shorter ignition delay and a longer combustion duration than the metal engine. The insulated engine fuel economy was approximately two percent worse on average for this series of tests. There was no attempt to optimize engine efficiency of the insulated engine by modifying the engine timing, coating, or other techniques. Yonushonis, T. M. Glenn Research Center CHROMIUM ALLOYS; COBALT ALLOYS; DIESEL ENGINES; ENGINE TESTS; METAL COATINGS; PROTECTIVE COATINGS; THERMAL CONTROL COATINGS; ZIRCONIUM OXIDES; DURABILITY; HEAT RESISTANT ALLOYS; HEAT SHIELDING; HEAT TRANSFER; THERMAL CONDUCTIVITY...
Author: Tide Water Oil Sales Corporation
Publisher:
ISBN:
Category : Lubrication and lubricants
Languages : en
Pages : 70
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Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
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Author: P. A. Vityaz
Publisher: Nova Novinka
ISBN: 9781617289217
Category : Friction
Languages : en
Pages : 0
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Book Description
The book presents a brief analysis of such methods of tribotechnology as the formation of coatings from a filler material on part surfaces owing to friction forces and coating deposition during friction with a lubricant containing plating components. Peculiarities of such methods of tribotechnology as running-in in a lubricant containing nano-sized hard components, which include nanodiamonds are considered in detail. This book examines how tribomechanical modification in the presence of lubricants with nanodiamonds improves tribological properties of friction pairs and prolongs the life of friction units.
