Analysis and Testing of Ceramic Matrix Composites in Diesel Engines
The use of ceramic material in diesel engines would be advantageous for many reasons: Insulation of the parts, incorporated in the combustion chamber, reduction of the oscillating masses, Increase of the combustion temperature and an increased theoretical efficiency. For this purpose the geometry of the CMC parts has to be optimised and then to be tested in a diesel engine. Therefore many variants with different geometries were evaluated using the FE analysis to choose the adequate design. Firstly the properties of the material composed of SiC fibers and a SiC matrix were evaluated. Uniaxial specimen tests with a special test control yielded the typical stress-strain curve for this material, necessary for calculations. Initially the assembly method for the cylinder liner, the piston insert and the cylinder head insert was examined. For the determination of the temperature induced stresses the orthotropic and temperature properties of the material were considered. For the stress analyses the contact behaviour of the parts was simulated by the use of gap elements. The operational conditions include beside thermal loads, the preload of the bolts and the piston insert and the pressure load, which arises during the combustion process. Thus the assembly method of the ceramic parts for the diesel engine was determined and a full scale version of the diesel engine was choosen. Finally the most promissing CMC variants were manufactured and tested in the diesel engine. Partly due to severe changes of the combustion process, the life of the CMC comfonents was too short for the complete realisation in dIesel engines. Many details, first of all the material itself, have to be improved in order to achieve successful results in the future.
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- 1.Leuchs, M, Ceramic Composite Applications in Diesel Engines — Experiences and Chances, 4th International Symposium on Ceramic Materials & Components for Engines, Goeteborg, Sweden, 1991Google Scholar
- 2.Agatonovic P and Koch F, The Thermal Analysis and Optimisation in Thermal Insulation of Engine Components, 5th Int. Conf. on Numerical Methods for Thermal Problems in Montreal, Quebeck, Canada, Ed. by R.w, Lewis, Pinedridge Press.Google Scholar
- 3.Dauchier M, Bernart G and Bonnet C, Properties of Silicon Carbide based Ceramic-Ceramic Composite, 30th National SAMPE March 19–21, 1985, p. 1519.Google Scholar
- 4.Agatonovic P and Grunmach R, Fatigue Life Tests on Composite Ceramic, Proc. 7th European Conference on Fracture (ECF7), Budapest, Hungary, 1988.Google Scholar