Determination of the injector type and location for a direct injected Wankel engine

Abstract

Direct injection on the Wankel engines has been practiced since the 1970’s. By applying direct injection in the Wankel engine, the specific fuel consumption and HC emissions, which are seen as disadvantages for this engine, might be reduced and the mixture formation is improved. In order to obtain a better mixture formation, the fuel injector must be located in a proper place and a correct direction. In addition, the most suitable injector for the engine structure should be selected. In this study, direct injection was applied for the RENESIS 13B Wankel engine and injector selection for the engine and the location of the injector on the housing were examined. In addition, the diameter of orifice and flow rate characteristics of the injector were investigated. According to the results, two types of injectors were selected. These injectors were called as low speed and high speed. An injector with a narrow nozzle angle (<30°) was used to deliver the fuel to the leading of the chamber, and the fuel injected after the intake ports closed. The orifice diameters of low-speed and high- speed injectors were measured 0.33 and 0.45 mm, respectively. In addition, both injectors have low speed rates when injection duration was below 2 ms. This flow rate was increased by providing high voltage.