Siren(旋笛式)激励系统设计及输出特性研究

Design and Output Characteristic of Siren Incentive System

关键词:  旋笛式激励系统  输出特性  共振模态  燃烧不稳定性

Key words:  Siren incentive system  Output characteristics  Resonance modes  Combustion instability

摘要:

设计了用于研究燃烧不稳定性、测量火焰传递函数(FTF)的Siren(旋笛式)激励实验系统。采用实验和数值的方法，研究了测量段进出口压差、脉动气路流量、脉动频率对系统输出特性的影响，并分析了系统的共振模态。结果表明，系统输出平均速度由测量段进出口压差决定，脉动速度[u]主要受脉动气路流量[m]的影响，且流量越大，脉动速度/平均速度百分比([u/u])也越大，实验中[u/u]最大超过了4%。脉动频率则通过影响旋笛出口压力脉动的分布进而影响速度脉动，而系统共振会导致输出[u/u]明显增大，系统共振频率在270Hz附近，此时旋笛出口压力脉动达到最大。

Abstract:

An experimental system with siren was designed for combustion instability study and flame transfer function (FTF) measurement. The factors influencing siren output characteristics were studied，and system resonance mode was analyzed by experimental and numerical method. The researched factors included pressure drop of measurement section，valve opening and pulsation frequency. The results indicate that siren incentive system output average speed is decided by pressure drop of measurement section. The mass flow pulsation through siren unsteady path[m]affects the amplitude of oscillating velocity[u]. The greater[m]is，the greater[u/u]becomes. In the experiment，the maximum value of[u/u]exceeded 4%. Besides，the frequency of pressure oscillation affects[u] though affecting siren actuator outlet pressure fluctuation distribution. The occurrence of system resonance leads to obvious increasing value of [u/u]. When frequency comes to 270Hz which is close to the resonant frequency，the siren outlet pressure fluctuation reaches the maximum value.