舰载机发动机冲击射流温度场及噪声特性分析

Analysis of temperature field and noise characteristics of impinging jet of carrier-based aircraft engine

[目的]偏转角对偏流板附近温度分布及辐射噪声大小的影响较大,适当的偏转角可以扩大舰载机周围安全区域范围。[方法]分析某型发动机尾喷管在全加力状态下,不同偏转角(β=35°,45°,55°)及不同监测距离(S=20D,30D,50D,80D)下偏流板附近的流场、温度场及声场特性。利用大涡模拟(LES)和声类比方法建立超声速射流冲击斜板计算模型,然后通过实验数据验证模型的正确性。[结果]结果显示,偏转角可改变温度场的分布,在β=45°时偏流板导流效果较好,板后人员及设备能得到最有效的保护,且偏流板逆流侧高温回流对舰载机后机轮基本无影响;偏转角对远场辐射噪声的影响较大,在S=40D时总声压级随偏转角的增大而增大,β=35°时影响舰员正常工作的噪声辐射范围最小。[结论]研究表明,虽然在β=45°时偏流板附近的舰员及设备所受的高温及噪声威胁最小,但为保证舰员在任何角度下都能正常工作,还是需要与尾喷管保持80D以上的距离。

[Objectives]As the deflection angle has great influence on temperature and noise radiation near the deflector of the impinging jet of a carrier-based aircraft,determining an appropriate deflection angle can expand the safe area around the aircraft.[Methods]This paper analyzes the flow field,temperature field and sound field characteristics near the deflector of a certain type of engine tail nozzle in full afterburner conditions under different deflection angles(β=35°,45°,55°)and different monitoring distances(S=20D,30D,50D,80D).Using large eddy simulation(LES)and acoustic analogy methods,a calculation model of a supersonic jet impinging on an inclined plate is established,and the correctness of the model verified by experimental data.[Results]The deflection angle changes the distribution of the temperature field.Whenβ=45°,the deflector has a better effect,personnel and equipment behind the deflector can be protected most effectively,and the high-temperature reflux on the countercurrent side of the deflector will affect the carrier aircraft.The rear wheel basically has no effect.The deflection angle also has great influence on far-field radiated noise.When noise monitoring distance S=40 D,the total sound pressure level increases with the increase of the deflection angle.Whenβ=35°,the noise radiation range affecting the normal work of personnel is at its smallest.[Conclusions]In general,whenβ=45°,personnel and equipment near the deflector suffer the least high temperature and noise threat.Even so,in order to ensure that the ground crew can work normally at any angle,the tail nozzle should be kept above 80D.