Design of a Novel Impulse Turbine for a Supercharged Single Cylinder Diesel Engine – A Simulation Approach

Abstract

Abstract Worldwide, single-cylinder engines have never been turbocharged commercially since the exhaust flow from the engine is intermittent. Hence, almost one-third of the energy supplied by the fuel as input to the single-cylinder engine is wasted as output into the atmosphere in the exhaust gas. In the current study, a supercharger was employed to enhance the power output from a single-cylinder diesel engine. A novel impulse turbine was proposed to recoup some energy from the pulsated exhaust flow. This novel supercharged, impulse turbine compounded single-cylinder engine layout was simulated using the commercially available AVL Boost model. Based on the results of the 1D model, an impulse turbine suitable for the supercharged engine was designed. Commercially available CAD modelling software NX was used to generate the 3D data of the designed impulse turbine. CFD analysis was conducted on the designed impulse turbine 3D model using commercially available Converge software. The impulse turbine design was further optimized based on the results of the CFD analysis. Design features like clearances of the turbine rotor, outlet port opening size, number of blades, blade speed, etc., were optimized. Simulated results show that the designed impulse turbine generated about 1.85 kW of power, thereby enhancing the power output of the supercharged engine by 15% at rated power conditions. Overall, the novel supercharged and impulse turbine compounded engine generated 14.65kW of power which was 39% higher than the base NA engine brake power output. Thus, the novel impulse turbine was designed using 1D and 3D simulations. Hence, with a simulation approach, the proposed novel method of employing a supercharged and impulse turbine compounded single-cylinder diesel engine was validated as the novel layout proved beneficial with improved engine performance.