Understanding the role of turbulence-induced blade configuration in improving combustion process for hydrogen-enriched rotary engine

Abstract

Benefits from the strong one-way flow within the rotor chamber, inducing turbulence is an effective means to improve flame evolutions and combustion characteristics of rotary engines. With the help of three-dimensional CFD simulations, the role of the turbulence-induced blade (TIB) configuration in strengthening ignition and combustion was assessed in a rotary engine fueled with hydrogen and gasoline, and the mixture formation, combustion process, and pollutants performance were addressed under different operating conditions. The numerical results show that introducing TIB in the rotor chamber is beneficial for improving the turbulent flow. The closer the blade position is to the spark plug, the higher the turbulent velocity and turbulent dissipation rate within the spark region. The leading-blade rotor chamber shows better combustion and emissions characteristics of the rotary engine. The TIB configuration is more sensitive to the combustion improvement of pure gasoline rotary engines compared with hydrogen-enriched rotary engines. The indicated power of the leading-blade engine is higher than that of the no-blade engine under various excess air ratio conditions. Especially for the excess air ratio of 1.1, the difference in the burned volume between the leading-blade and no-blade cases is more pronounced. Compared with stoichiometric operations, the TIB configuration shows better emission performance at lean-burn operations. The improvement of the turbulence level increases significantly by the leading-blade configuration at a lower engine speed. With the increase of the engine speed, the decrease in peak pressure is more significant in the leading-blade rotor chamber. The results shall give insights into the feasibility of the TIB configuration on the improvement of rotary engine performance in engineering applications.