Effect of Swirl Induction by Internally Threaded Inlet Manifolds on Exhaust Emissions of Single Cylinder (DI) Diesel Engine

The aim of paper is to design different types of inlet manifolds for direct injection (DI) single cylinder diesel engine in order to create the turbulence by swirl. A good swirl promotes the fast combustion and improves the efficiency. The engine should run at low speeds in order to have low mechanical losses and fast combustion, enabling good combustion efficiency. Therefore to produce high turbulence prior to combustion within the cylinder, swirl induced by the inlet manifold will be helpful. This paper aims at studying the effect of air swirl generated by directing the air flow in intake manifold on engine performance as well as on its exhaust emissions. The turbulence is achieved in the inlet manifold with different types of internal threads of constant pitch. In view this, experimental investigation has been carried out to find the effect of swirl on the performance characteristics of the engine as well as on its exhaust emissions, by inducing swirl in inlet manifolds with three different types of internal threads viz. acme, buttress and knuckle threads of constant pitch. It is inferred that, the inlet manifold with buttress threads gives better performance and yields less exhaust emissions compared to inlet manifolds with acme and knuckle threads. This is because inlet manifold with buttress threads achieved a higher swirl coefficient and swirl ratio compared with inlet manifolds having acme and knuckle threads.