Studies on the effect of turbulence on the performance characteristics of a spark–ignition engine

Turbulence in a spark–ignition engine significantly influences the performance and emission characteristics. Furthermore, it has been recognised that the presence of turbulence in the inlet manifold of a spark–ignition engine up to a certain level does improve the fuel economy. Hence, in this article, experimental investigations relating to the effect of turbulence generation in the inlet manifold on the overall performance of a spark–ignition engine are reported. Turbulence generators creating 50 and 75 per cent blockage with delta–wing–type blades were used in the inlet manifold of a single–cylinder spark–ignition engine. Subsequently, blade–type turbulence generation were introduced in the same manifold. A comparison between the two cases was made with reference to the overall performance of the engine by measuring the engine power and the turbulence with the help of a hot–wire anemometer. These investigations have shown that blade–type turbulence generators create a significantly larger amount of turbulence, leading to a loss of engine power compared with the delta–wing–shaped generator. However, it is noticed that there is a slight improvement in the performance of the engine when the delta–wing–type of turbulence generator is used compared with the conventional engine.