- Tytuł:
- Analysis and research of piston working conditions of combustion engine in high thermal load conditions
- Autorzy:
-
Jankowska-Sieminska, B.
Jankowski, A.
Slezak, M. - Tematy:
-
combustion engine
piston
thermal load
thermal expansion
thermal shock - Pokaż więcej
- Wydawca:
- Instytut Techniczny Wojsk Lotniczych
- Powiązania:
- https://bibliotekanauki.pl/articles/243400.pdf Link otwiera się w nowym oknie
- Opis:
- Explanation of phenomena occurring in pistons of combustion engines which appear during heating and cooling processes in reference to standard materials and composite materials of high material proprieties is aim of the paper. Bring over researches were mostly directed on measurements of difference dimensions which appear during the piston work in the combustion engine. The paper concentrates on phenomenon of different proprieties of materials. The thermal stresses and shocks differ. In the thermal shock, thermal stresses are caused by instantaneous temperature gradients which appear at high engine speed. These stresses are determined thro temperature distribution and they do not differ from stresses in steady-state conditions. Researches concerning thermal expansions were performed by means of sensitive dilatometer which can work in simple and differential system. Changes of dimensions versus temperature function were measured with inductive sensor and the sensitive Pt-ptrh thermocouple, and results were referred to reference material-Platinum. Research results are illustrated on diagrams of different courses of changes of the of thermal expansion coefficient during heating and cooling of standard and composite materials. Values of the thermal expansion coefficient a for the heating and cooling are smaller for composite alloys. The course of the coefficient â during cooling can be higher or lower from the coefficient a during heating. Similar values were also received. Maximum differences were of 10%. Smaller values of the coefficient a for composite alloys cause that for such the same thermal loads temperature gradients will be smaller for composite alloys. Courses of changes of the coefficient â have a different characteristics suited from chemical composition of alloy, granularity of the composite component and thermal treatment.
- Dostawca treści:
- Biblioteka Nauki
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