IC engine exhaust pipe - has venturi nozzle at end to cool gases by drawing in ambient air

摘要

The exhaust pipe of a vehicle internal combustion engine terminates in an injector nozzle working on the Venturi principle. This nozzle termination is installed downstream of the exhaust silencer. The nozzle is surrounded by an outer tube (T) which is open at the inlet end (b1) to atmosphere. The Venturi effect of the nozzle draws cold ambient air through the outer tube and as this flows over the nozzle (A) it cools the exhaust gas. The drop in pressure resulting from the cooling sets up a pressure difference between the engine and the end of the exhaust which forces exhaust gases out of the engine more effectively than the motion of the engine pistons by itself. This improves the performance of the engine.