涡轮级均匀与非均匀进口熵条件下声场数值研究

Numerical investigation of sound field with uniform and non-uniform inlet entropy in a gas turbine stage

通过在涡轮级进口周向上设置周期性总温分布,将转静干涉以及进口温度不均匀分布对声场的影响分离到各个周向模态上。通过均匀进口熵条件以及非均匀进口熵条件下的两个算例进行比较,直观的得出涡轮进口非均匀熵对涡轮转子后的声场的影响。算例结果表明:在只受周期进口总温分布影响的周向模态上,非均匀进口熵条件对声场的影响明显。相比均匀熵进口条件,非均匀熵进口条件下的总声功率级,一倍叶片通过频率下BPF增加约0.23 dB,二倍叶片通过频率增加约2.64 dB,通过数值方法验证了间接燃烧噪声。

To set the periodic total temperature distribution in the inlet of turbine stage,the effect of rotor-stator interaction and periodic temperature-rotor interaction was divided on different circumferential modes number.After the comparison between uniform entropy inlet case and non-uniform entropy inlet case,it can be seen that the non-uniform entropy inlet affected the sound field in the duct after rotor clearly,especially in the circumferential modes number affected only by the periodic total temperature-rotor interaction.The difference of total sound power level between non-uniform entropy inlet case and uniform entropy case is 0.53dB in the first blade passing frequency（1BPF）,2.64dB in 2BPF.Thus the indirect combustion noise is ualidated by numerical simulation method successfully.