湍流射流点火诱导两次喷射高压直喷甲烷着火规律试验研究OA北大核心

The ignition and combustion phenomenon of active pre-chamber ignited dual-methane injection jets were investigated in a constant volume combustion chamber with an active pre-chamber and high-pressure injector.The effects of injection ignition delay,the injection pressure of methane and the pulse width of the first methane injection were studied.The results show that,with other conditions remaining unchanged,misfire occurs when the ignition delay(ti)is-30 ms.When ti is increased to-10 ms,an unstable ignition phenomenon occurs,where the flame extinguishes and reignites again.Increasing ti from 0 ms to 100 ms raises the peak combustion pressure from 1.56 MPa to 2.26 MPa and the peak pressure timing advances from 130 ms after ignition to 50 ms.Meanwhile,both the speed of thermal jet and flame increase.For instance,the flame propagation speed increases from 10 m/s to 30 m/s.Furthermore,as the injection pressure increases from 5 MPa to 10 MPa,the peak pressure changes from 0.96 MPa to 2.26 MPa,and peak pressure timing advances from 100 ms to 50 ms.The flame speed in the main combustion chamber increases from 5 m/s to 30 m/s.Additionally,changing the pulse width of the first injection affects both the peak pressure and peak pressure timing as well.Increasing the first injection pulse width from 40 ms to 80 ms raises the peak pressure from 1.87 MPa to 2.26 MPa,and the peak pressure timing advances.However,it has little effect on the thermal jet speed and the flame speed.