Students: |
Manohar Vittal, David Weller, William Swain, Howard Hess |
Faculty/Supervisors: |
Dr. Alan Bentz (retired), US Coast Guard R&D Center Prof. André Boehman, Director of the Combustion Laboratory |
Objective: |
Determine the mechanisms by which thermal barrier coatings reduce particulate emissions from a low heat rejection diesel engine |
Approach: |
The experimental facility consists of a single-cylinder Yanmar TS-180 Diesel utility engine on a Clayton CAM-50 waterbrake dynamometer, and instrumentation for gaseous and particulate emissions measurements. |
Results: |
A primary result of this work has been the discovery of significant morphological and composition changes in the particulate emissions, in addition to total particulate mass reductions, when thin thermal barrier coatings are applied to the combustion chamber surfaces. |
 |
Scanning electron microscope images of diesel particulate matter from (a) a single-cylinder diesel engine and (b) the same engine with ceramic coatings applied to the piston crown, cylinder head, and valves. The thermal barrier coating enhances the oxidation of condensable hydrocarbons that agglomerate with the diesel soot. In figure (b) the particulate matter has a more granular appearance, showing that the soot spherules are not bound together by heavy hydrocarbons. |  |
| (a) | (b) |
To date, a number of publications have been produced primarily focusing on the effects of the thermal barrier coatings on NOx, CO and total particulate emissions and the morphology and chemical composition of the particulate matter. These publications include:
Vittal, M., J. A. Borek, D. A. Marks, A. L. Boehman, D. A. Okrent and A. P. Bentz. The Effects of Thermal Barrier Coatings on Diesel Engine Emissions. Accepted for the ASME Journal of Engineering for Gas Turbines and Power, 1999.
Weller, D. E., W. H. Swain, H. Hess, A. L. Boehman and J. M. Perez. Changes in Particulate Composition and Morphology When Using Vegetable Oil Lubricant in a Low Heat Rejection Engine. Society of Automotive Engineers Technical Paper No. 1999-01-0975. Presented at the 1999 SAE International Congress and Exposition, Detroit, MI, March, 1999.
Boehman, A. L., W. H. Swain, D. E. Weller and J. M. Perez. Use of Vegetable Oil Lubricant in a Low Heat Rejection Engine to Reduce Particulate Emissions. SAE paper no. 980887 presented at the 1998 International Congress and Exposition, Detroit, MI, February, 1998.
Vittal, M., J. A. Borek, A. L. Boehman and D. A. Okrent. The Influence of Thermal Barrier Coatings on the Composition of Diesel Particulate Emissions. SAE paper no. 972958 presented at the 1997 SAE Fall Fuels & Lubricants Meeting, Tulsa, OK, October, 1997. Published in Combustion and Emissions in Diesel Engines, Society of Automotive Engineers, Inc. Warrendale, PA, pp. 1-6.
Marks, D.A. and A. L. Boehman. The Influence of Thermal Barrier Coatings on Morphology and Composition of Diesel Particulates. SAE paper no. 970756 presented at the 1997 International Congress and Exposition, Detroit, MI, March, 1997. Published in Diesel Engine Combustion Processes and Emission Control Technologies, Society of Automotive Engineers, Inc., Warrendale, PA, pp. 51-60.