| Popis: |
The performance of a conventional, carburated, two-stroke, spark-ignition (SI) engine can be improved by providing moderate thermal insulation in the combustion chamber. In the present investigation the combustion chamber surface was coated with a 0.5-mm thickness of partially stabilized zirconia, and experiments were carried out in a single cylinder, two-stroke SI engine with gasoline and methanol as fuels. The results indicate that with gasoline as fuel, the thin ceramic-coated combustion chamber improves the part load to medium load operation considerably, but it affects the performance at higher speeds and at higher loads to the extent of knock and loss of brake power by about 18%. However with methanol as a fuel the performance is better under most of the operating range and free from knock. Emissions are significantly reduced by about 3 to 4% volume, for both gasoline and methanol fuels due to relatively lean operation and more complete combustion. 35 refs., 13 figs., 3 tabs. |
