轴流压气机级内污垢沉积影响的数值研究

Numerical Study on the Impact of Fouling on Axial Compressor Stages

关键词:  航空发动机  轴流压气机级  污垢沉积  粗糙度  厚度

Key words:  Aircraft engine  Axial compressor stage  Fouling  Roughness  Thickness

摘要:

采用三维数值方法,对具有一定典型性的真实压气机级NASA stage 35进行研究,通过与文献中实验数据的对比,校核了商业CFD计算代码的可靠性,得到的性能曲线与实验数据有较好的一致性；通过对污垢沉积引起的叶片厚度和壁面粗糙度的增加来模拟不同的污垢沉积程度对压气机级性能的影响。结果表明,增加壁面粗糙度将显著降低压气机级等熵效率和总压比,喘点和堵点的流量均有所下降,对稳定工作范围影响不大；增加叶片厚度大幅降低堵点流量而对喘点流量影响较小,使得压气机级的稳定工作范围明显减小；动叶壁面粗糙度的增加相比静叶对级性能的影响明显要大。 

Abstract:

Three-dimensional numerical method has been used in an investigation of NASA stage 35 which was a typically realistic compressor stage. Firstly, the numerical model was validated against the experimental data available from literature to check accuracy of the commercially computational fluid dynamic code. Computed performance maps showed good agreement with experimental data. Then, the model was used to simulate the effect of fouling on compressor stage in terms of imposing different combinations of added thickness and surface roughness levels. As a result, with surface roughness increasing, the compressor isentropic efficiency and total pressure ratio significantly reduced, mass flow rate decreased at both choked and near stall region, and surface roughness had little effect on compressor stable operating range. When the adding thickness increased, mass flow rate had a great drop at a choked point, but different at near stall point, and compressor stable operating range reduced obviously. The augment of surface roughness on rotor passage is the main fact of performance deterioration and it needs to be investigated.