不同来流条件对涡轮叶片表面颗粒沉积影响的实验研究

Experimental Simulation of Particle Deposition on TurbineBlade Surface with Different Free Stream Conditions

关键词:  涡轮叶片  颗粒沉积  攻角  颗粒浓度  加速沉积

Key words:  Turbine blade  Particle deposition  Angle of attack  Particle concentration  Accelerated deposition

摘要:

为了研究微颗粒在涡轮叶片表面的沉积特性，采用熔融态石蜡代替熔融态微颗粒，通过石蜡在平板表面的沉积来模拟真实涡轮叶片表面的微颗粒沉积，从而开展较低温度条件下微颗粒的沉积实验。通过实验观察石蜡在试验件表面附着固化分布，同时测量石蜡在平板表面不同位置的沉积量，研究了不同来流攻角、颗粒浓度对平板表面颗粒物沉积的影响规律，分析了等效加速实验的颗粒物沉积效果。结果表明：颗粒物沉积主要发生在平板前缘及压力面的中后部，前缘的颗粒沉积物质量远大于压力面和吸力面的。随着攻角的增大，压力面和吸力面沉积量显著增大，前缘变化不明显；随着来流颗粒浓度的增加，前缘和压力面的沉积量增加；对于已有等效加速实验准则，保持总粒子喷射质量相同，在颗粒浓度升高，实验时间变短的情况下，平板前缘位置的沉积量增大。

Abstract:

Low melting temperature wax droplets were injected to simulate the micro-particle deposition on the turbine vane surface in order to study the deposition characteristics on the turbine vane surface. Experimental simulation was performed for a plate to assess how the deposit formation was influenced by the angle of attack （AOA） and particle concentration， based on observing wax deposition and quantifying mass distribution. The dynamic deposition results were analyzed from an equivalent accelerated test. Results showed deposition occurred mainly on the leading edge and the middle-rear part of pressure surface. Deposition mass was far larger on the leading edge than that on pressure and suction surfaces. The deposition mass on the pressure and suction surfaces increased significantly with AOA increasing， while there was few change in the deposition on the leading edge. Deposition mass became larger on the leading edge and pressure surface with the increase in freestream concentration of particle. Deposition mass on the plate leading edge increased with increasing particle concentration and shortening the test time， based on the law of constant total particle ejection mass.