加力用扇形喷嘴雾化特性试验

根据加力燃烧室内锥凹腔点火与联焰要求,设计了扇形喷嘴并开展相应的雾化试验,研究了供油压差、扇形角度及扇形出口高度等参数对流量特性和雾化特性的影响以及加力环境下横向气流的温度、速度和供油压差对索太尔平均直径(SMD)及穿透深度的影响。采用称质量法测量流量系数,利用马尔文粒度仪和高速摄影仪对下游SMD、雾化角度及穿透深度进行测量。结果表明:①供油压差增大,流量系数先减少,后稳定;②供油压差一定,扇形出口角度越大,流量系数和雾化角度也越大;③扇形出口高度增加,雾化效果变好;④出口位置对雾化特性影响不大;⑤供油压差越大,穿透深度越大,SMD减小;⑥横向气流速度越大、温度越高,穿透深度越浅,油雾场越靠近下游;⑦横向气流温度越高, SMD越小。

Experiment on atomization characteristics of fan nozzle

According to the requirements of the cone cavity ignition and the flame crossover in the afterburner, the fan nozzle for the cavity ignition and flame crossover was designed, and the corresponding atomization test was carried out to study the effect of the fuel supply pressure difference, fan angle and the fan exit height on the discharge and atomization characteristics of the fan nozzle and the effect of the temperature, speed and fuel supply pressure difference of the lateral airflow on the penetration depth and the Sauter mean diameter (SMD) under afterburning environment. Weighing method was used to test the discharge coefficient of the fan nozzles. And the Malvern laser particle size analyzer and high speed camera were used to measure the SMD of the droplets, spray angle and penetration depth, respectively. Results suggested that: (1) with the increase of fuel supply pressure difference, the discharge coefficient decreased first and then became insensitive to fuel supply pressure difference. (2) Under the same fuel sypply pressure difference, the discharge coefficient and spray angle increased with the increase of fan angle. (3) With the increase of fan exit height, the atomization effect became better. (4) In addition to the above mentioned results, the mounting position had less effect on the atomization characteristics of the fan nozzles. (5) As the oil supply pressure difference increased, the penetration depth of the fan nozzle increased, and the SMD decreased. (6) The greater lateral airflow speed and temperature, the smaller the penetration depth, and the oil mist field was closer to the downstream section. (7) As the lateral airflow temperature increased, the SMD decreased.