非定常条件下喷嘴结构对燃油流量脉动的影响

假设油路处于小脉动条件下,燃油流量连续,以流量数为中间变量,推导了燃油流量脉动关于喷嘴结构的关系模型.得出结论:当外部激励一定时,燃油流量脉动与流量数成正比,与平均燃油压降的0.5次方成反比.通过喷嘴标定得出了减小流量数进而减小燃油流量脉动的方法:增加节流级数、减小节流面积,并用脉动试验证明了此方法的正确性,为喷嘴设计者在面对不稳定性问题时提供了一般的设计步骤. 

Nozzle structure's influence on fuel flow oscillation in unsteady conditions

Assuming that fuel flow is continuous under small oscillation conditions, a correlation model about fuel flow oscillation and the nozzle structure was derived with flow number as an intermediate variable. Under this model, conclusion are made as follows: fuel flow oscillation is proportional to the flow number, and inversely proportional to the 0.5th power of average fuel pressure drop when the external excitation is given. Methods of decreasing fuel flow oscillation by decreasing flow number are obtained by nozzle calibration: increasing the throttling stage, decreasing throttling area. This method is validated through oscillation experiment. A general design procedure is suggested for nozzle designers in face of the instability problem.