scholarly journals The Influence of Thermal Barrier Coating Surface Roughness on Spark-Ignition Engine Performance and Emissions

Author(s):  
Silvio Memme ◽  
James S. Wallace

The separate effects on heat transfer of 1) piston crown surface finish and 2) the use of a metal based thermal barrier coating (MTBC) on the piston crown of a spark ignition (SI) engine were quantified through experimental analysis in a single cylinder CFR engine. Measured engine parameters such as power, fuel consumption, emissions and cylinder pressure were used to identify the effects of the coating and its surface finish. Two piston coatings were tested: a baseline copper coating and a metal-based thermal barrier coating. Each coating was tested at multiple surface finishes. Tests showed that reducing surface roughness of both coatings increased in-cylinder temperature and pressure as a result of reduced heat transfer through the piston crown. For both coatings, this resulted in small improvements (∼3%) in power and fuel consumption, while also having a measurable effect on emissions. Oxides of nitrogen emissions increased while total hydrocarbon emissions generally decreased as a result of polishing. The polished coatings were also seen to increase in-cylinder peak pressures and burn rates. Improvements attributed to the TBC were found to be small, but statistically significant. At an equivalent surface finish, the MTBC-coated piston produced slightly higher power output and peak pressures. Hydrocarbon emissions were also seen to be significantly higher for the MTBC-coated piston due to its porosity. The effectiveness of the coating was found to be highly dependent on surface finish.

Author(s):  
Michael Marr ◽  
James S. Wallace ◽  
Larry Pershin ◽  
Sanjeev Chandra ◽  
Javad Mostaghimi

A novel metal-based thermal barrier coating was tested in a spark-ignition engine. The coating was applied to the surface of aluminum plugs and exposed to in-cylinder conditions through ports in the cylinder wall. Temperatures were measured directly behind the coating and within the plug 3 and 11 mm from the surface. In-cylinder pressures were measured and analyzed to identify and quantify knock. Test results suggest the coating does not significantly reduce overall heat transfer, but it does reduce the magnitude of temperature fluctuations at the substrate surface. It was found that heat transfer can be reduced by reducing the surface roughness of the coating. The presence of the coating did not promote knock.


Author(s):  
Michael A. Marr ◽  
James S. Wallace ◽  
Larry Pershin ◽  
Sanjeev Chandra ◽  
Javad Mostaghimi

A novel metal-based thermal barrier coating was tested in a spark-ignition engine. The coating was applied to the surface of aluminum plugs and exposed to in-cylinder conditions through ports in the cylinder wall. Temperatures were measured directly behind the coating and within the plug 3 and 11 mm from the surface. In-cylinder pressures were measured and analyzed to identify and quantify knock. Test results suggest the coating does not significantly reduce overall heat transfer, but it does reduce the magnitude of temperature fluctuations at the substrate surface. It was found that heat transfer can be reduced by reducing the surface roughness of the coating. The presence of the coating did not promote knock.


2019 ◽  
pp. 146808741989348 ◽  
Author(s):  
Eric Gingrich ◽  
Michael Tess ◽  
Vamshi Korivi ◽  
Peter Schihl ◽  
John Saputo ◽  
...  

Thermal barrier coatings of various thickness and surface roughness were applied to the piston crown of a single-cylinder research engine and tested over a range of high-output diesel operating conditions, some near 30 bar gross indicated mean effective pressure. Three yttria-stabilized zirconia coated pistons were compared to a baseline metal piston. At each operating condition, a start-of-injection sweep was conducted to generate efficiency trends and find the optimal combustion phasing. Three variations of pistons coated with a graded-layer thermal barrier coating were tested: (1) 0.185 mm coating thickness with a surface roughness of approximately Ra = 11.8 µm, (2) 0.325 mm thickness with Ra = 11.8 µm, and (3) 0.325 mm thickness with Ra = 6.0 µm. Both coated pistons with Ra = 11.8 µm did not show any statistically significant improvement to engine performance when compared to the metal baseline piston, but did produce higher filter smoke numbers. The coated piston with Ra = 6.0 µm and 0.325 mm showed an increase of gross indicated thermal efficiency of up to 3.5% (relative) compared to the metal baseline piston for operating conditions comparable to standard engine operation and a reduction of filter smoke number back to the metal baseline. The increase in efficiency was found to correlate with additional late-cycle apparent heat release and a reduction in in-cylinder heat transfer. The very high-output conditions showed statistically insignificant changes in performance or heat transfer, which may have been related to the long injection duration used for these cases targeting outside of the piston bowl.


2017 ◽  
Vol 137 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Tetsuo Fukuchi ◽  
Norikazu Fuse ◽  
Mitsutoshi Okada ◽  
Tomoharu Fujii ◽  
Maya Mizuno ◽  
...  

Author(s):  
J. D. MacLeod ◽  
J. C. G. Laflamme

Under the sponsorship of the Canadian Department of National Defence, the Engine Laboratory of the National Research Council of Canada has evaluated the influence of applying a thermal barrier coating on the performance of a gas turbine engine. The effort is aimed at quantifying the performance effects of a particular ceramic coating on the first stage turbine vanes. The long term objective of the program is to both assess the relative change in engine performance and compare against the claimed benefits of higher possible turbine inlet temperatures, longer time in service and increased time between overhauls. The engine used for this evaluation was the Allison T56 turboprop with the first stage turbine nozzles coated with the Chromalloy RT-33 ceramic coating. The issues addressed in testing this particular type of hot section coating were; 1) effect of coating thickness on nozzle effective flow area; 2) surface roughness influence on turbine efficiency; This paper describes the project objectives, the experimental installation, and the results of the performance evaluations. Discussed are performance variations due to coating thickness and surface roughness on engine performance characteristics. As the performance changes were small, a rigorous measurement uncertainty analysis is included. The coating application process, and the affected overhaul procedures are examined. The results of the pre- and post-coating turbine testing are presented, with a discussion of the impact on engine performance.


Energies ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 1000 ◽  
Author(s):  
Prasert Prapamonthon ◽  
Soemsak Yooyen ◽  
Suwin Sleesongsom ◽  
Daniele Dipasquale ◽  
Huazhao Xu ◽  
...  

1988 ◽  
Vol 110 (1) ◽  
pp. 88-93 ◽  
Author(s):  
R. M. Watt ◽  
J. L. Allen ◽  
N. C. Baines ◽  
J. P. Simons ◽  
M. George

The effect of thermal barrier coating surface roughness on the aerodynamic performance of gas turbine aerofoils has been investigated for the case of a profile typical of current first-stage nozzle guide vane design. Cascade tests indicate a potential for significant extra loss, depending on Reynolds number, due to thermal barrier coating in its “as-sprayed” state. In this situation polishing coated vanes is shown to be largely effective in restoring their performance. The measurements also suggest a critical low Reynolds number below which the range of roughness tested has no effect on cascade efficiency. Transition detection involved a novel use of thin-film anemometers painted and fired onto the TBC surfaces.


2007 ◽  
Vol 336-338 ◽  
pp. 1818-1822
Author(s):  
Jin Sheng Xiao ◽  
Kun Liu ◽  
Wen Hua Zhao ◽  
Wei Biao Fu

A thermal shock experiment is designed to explore the thermal shock properties of ceramic/metal gradient thermal barrier coating. The specimens are heated up by oxygen-acetylene flame and cooled by water spray. The experiment procedure includes two stages, heating the specimen from the initial temperature 30°C for 40s, and then cooling for 20s. The heat transfer and the associated thermal stresses produced during the thermal shock procedure are simulated by finite element method. Experimental results indicated that the specimen of gradient coating behaves better in thermal shock experiments, which agree with the results of simulation.


Author(s):  
Muhammad Asad Riaz

An observational study of thermal barrier coating (TBC) on the working of 4-stroke single cylinder petrol engine was studied. Yttria Stabilized Zirconia (YSZ) used as coating material. YSZ has less thermal conductivity, sustainability under high temperature and pressure. Main aim of TBC is to decrease heat losses to the cooling jacket of the engine. YSZ is coated on the piston crown by Plasma spray method. YSZ coating improves the performance of petrol engine. Experimental study was carried out on 4-stroke single cylinder OHV petrol engine 25‎°C inclined cylinder horizontal shaft engine on performance of ceramic coated engine and compared with baseline engine under different speed. Results show that ceramic coated engine is more effective than conventional engine as brake specific fuel consumption (BSFC) is reduced 2-4% than normal piston engine, brake thermal efficiency (BTE) of modified engine is expanded 4-8% than unmodified engine. Indicated thermal efficiency (ITE) of modified piston engine is increased 5-10% than normal engine. Mechanical efficiency (ME) of the TBC engine is increased 4-10% than standard engine. Volumetric efficiency (VE) of modified engine is decreased 3-9% when compared with standard engine and exhaust gas temperature (EGT) of ceramic coated engine is increased 1-3% than unmodified engine. KEYWORDS: Petrol Engine, Thermal barrier coating (TBC), Yttria Stabilized Zirconia (YSZ). Mechanical Efficiency


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