基于动叶污垢沉积的数值模拟

采用三维数值方法研究了污垢沉积对压气机动叶性能的影响.对具有一定典型性的真实压气机动叶NASA Rotor 37进行数值研究,通过与文献中实验数据的对比,校核了商业CFD(computational fluid dynamics)计算代码的可靠性,结果表明计算得到的性能曲线与实验数据有较好的一致性,应用于数值模拟手段是可行的.随后通过增加叶片和端壁的表面粗糙度和厚度来模拟不同的污垢沉积程度对压气机动叶性能的影响,结果表明:增加叶片厚度和表面粗糙度都将引起总压比和等熵效率降低;增加表面粗糙度将导致流量下降,稳定工况范围向小流量方向移动;而增加叶片厚度将使得稳定工况范围明显减小,堵点流量下降较显著,这将导致动叶工作特性恶化程度增大.

Numerical simulation of fouling deposition in compressor rotor

Three-dimensional numerical simulation to study the influence of fouling deposition on compressor rotors was carried out.As a representative of realistic compressor rotor,the NASA Rotor 37 was considered to perform a numerical investigation and by comparing with the experimental data available from literature,the reliability of commercial CFD(computational fluid dynamcics) computational code was validated.The results show that computed performance maps achieve a good agreement with the experimental data,so it’s practicable using the means of numerical simulations on the study.Then the influence of different fouling deposit degree on compressor rotor performance was simulated by adding surface roughness and thickness on the blade and end-wall.The results indicated that increasing surface roughness and thickness on the blade can make total pressure ratio and isentropic efficiency decrease,and increasing wall roughness can make flow reduce,rotor stable operating range transfer to small flow.Also,increasing blade thickness can make stable operating range decreased obviously,the flow reduced observably at the blockage point,which lead to increase on the deterioration degree of rotor performance.