Journals / Süleyman Demirel Üniversitesi Mühendislik Mimarlık Fakültesi Makina Mühendisliği Dergisi / 1996 / Cilt: 1 - Sayı: 10
Egzoz valfının termal genleşmesiyle ısı transferi
- Pages
- 10–15
- DOI
- —
Abstract
The correct operation of IC engine valves requires maintaining suitable heat transfer condition, for example, between valve stem and valve guide. In this case heat transfer depends mainly upon the clearance between these elements for engine operation conditions. An analysis of heat transfer conditions between valve stem and guide at sliding contact in reciprocating motion was carried out. Experimental investigations of linear thermal expansion coefficient of stem and guide materials were performed for temperature range corresponding to engine operating condition. The investigations of temperature influence on thermal expansion coefficients were conducted with use of the dilatometer working in simple and differential modes. The clearance between valve stem and guide as a function of temperature was determined. It results from analysis and investigations that better heat transfer conditions occur for small differences in thermal expansion coefficients for both materials. However, big differences in values of these coefficients, disadvantageous for heat transfer conditions, were found.
Özet
The correct operation of IC engine valves requires maintaining suitable heat transfer condition, for example, between valve stem and valve guide. In this case heat transfer depends mainly upon the clearance between these elements for engine operation conditions. An analysis of heat transfer conditions between valve stem and guide at sliding contact in reciprocating motion was carried out. Experimental investigations of linear thermal expansion coefficient of stem and guide materials were performed for temperature range corresponding to engine operating condition. The investigations of temperature influence on thermal expansion coefficients were conducted with use of the dilatometer working in simple and differential modes. The clearance between valve stem and guide as a function of temperature was determined. It results from analysis and investigations that better heat transfer conditions occur for small differences in thermal expansion coefficients for both materials. However, big differences in values of these coefficients, disadvantageous for heat transfer conditions, were found.