Experimental research on cycle-to-cycle fluctuation of diesel HCCI combustion

Effects of engine load and speed, injection pressure, exhaust gas recirculation (EGR) and supercharging on combustion cycle-to-cycle fluctuation were studied experimentally in a HCCI combustion diesel engine. Results indicate that cycle-to-cycle fluctuation decreases with engine load increase and in low load range increases with engine speed increase; under different load conditions, cycle-to-cycle fluctuation increases first and then decrease with injection pressure increase and reaches its peak value at injection pressure of 90 MPa; EGR rate increase leads to cycle-to-cycle fluctuation increase slightly, and the cycle-to-cycle fluctuation variation with supercharging pressure increase exhibits a decrease-increase-decrease tendency, more obvious in low load.