石蜡基燃料固液混合发动机燃面退移过程预示方法

Prediction method on the regression process of paraffin-based hybrid motor

与传统固液混合发动机燃料相比,石蜡基燃料的液滴“夹带”机制对固液混合发动机燃料表面的“阻滞”效应存在缓解作用,有效提高了燃面退移速率。通过引入吹风系数加权因子表征了该缓解作用,建立了石蜡基燃料燃面退移过程预示方法,为阐述石蜡基燃料的燃面退移过程提供了理论基础。结果表明,当吹风系数加权因子n=0.4时,该方法的预示结果与实际测量值最为接近;石蜡基燃料“夹带”机制可以极大提高固体燃料燃面及附面层内的吸热量,缓解了“阻滞”效应,但使得燃气向燃面的辐射换热热流减弱;随着燃面退移,固液混合发动机燃料表面的“阻滞”效应逐渐减弱,石蜡基燃料“夹带”机制对于“阻滞”效应的缓解作用,随着该效应自身的减弱也逐渐减弱。

Compared with traditional solid-liquid hybrid fuel,droplet entrainment mechanism of paraffin-based fuel has the relief action on the blocking effect of hybrid motor fuel surface,which effectively improves the regression rate of the combustion surface.The relief action was characterized by introducing the weighted factor of blowing coefficient,and the prediction method on the regression process of paraffin-based hybrid motor was established,which can provide a theoretical basis for describing the fuel surface regression process of paraffin-based fuel.The results show that when the weighted factor of blowing coefficient n=0.4,the prediction result is closest to the actual measured value;droplet entrainment mechanism of the paraffin-based fuel can greatly improve heat transfer on the combustion surface and boundary layer,make blocking effect and radiation heat flux weakened;with the regression of fuel surface,the blocking effect on the fuel surface of hybrid motor is weakened,and the relief action of droplet entrainment mechanism of paraffin-based fuel on blocking effect is also gradually weakened as blocking effect itself weaken.