A development study of titanium exhaust system for sports cars

摘要

One of the most important reasons for using titaniumrnin exhaust systems is weight reduction, which bringsrnbetter results both in the vehicle performance and fuelrnefficiency. The application of titanium and its alloys tornautomotive parts has grown dramatically in the lastrnyears. Exhaust system applications, includingrnmufflers and exhaust pipes, have been a main targetrnfor titanium in cars. In addition to weight savings, thernvisual appearance of titanium as well as performancernwith titanium attracts customers. A car exhaustrnsystem looks simple at first glance. But a closer lookrnshows that it is a complex system that has arnsignificant effect on the performance of a racing or arnregular sports car. Successful design of a titaniumrnexhaust system commences with considering thernconditions to which a particular exhaust componentsrnare to be exposed. The titanium alloy should bernselected according to the operating conditions,rnespecially the maximum operating temperature underrnupset conditions. In turn, the physical and mechanicalrncharacteristics of the alloy selected can dictate somerndesign features. Therefore the titanium exhaustrnsystem design has been improved by the help ofrncomputer-aided design (CAD) in combination withrnthermal, structural and fluid dynamic analyses basedrnon the finite-element method (FEM). Usually, the finalrnexhaust form is confirmed after intensive andrnsuccessful experimental analyses of physicalrnprototypes. The aim of this paper is to demonstraternthe development process of a titanium exhaustrnsystem using different numerical analyses as well asrnexperimental methods. Finally, some of the newlyrndeveloped Akrapovic lightweight and highrnperformance titanium exhaust systems for sports carsrnare presented.