压气机动叶片流固耦合振动分析研究

Research on Vibration Analysis of Moving Blades of Compressor Based on the Fluid-solid Coupling Method

分析计算出燃气轮机动叶片在离心-气动复合力场作用下的动频和振型云图,对于建立叶片动力学模型具有重要意义。通过采用数字化建模和流固耦合方法,分别建立了某重型燃气轮机轴流式压气机动叶片在离心-气动复合力场作用下的叶片模型和流场三维模型,确定了流场边界条件和流场数值计算模型,求得流场流速分布以及流场内腔旋转壁面的压力分布情况和压气机叶片上的载荷分布情况,并进行预应力模态分析。在此基础上,分析论述了气动力场作用下叶片的应力分布状态、气动力场和离心-气动复合力场对叶片固有频率的影响趋势。此外,通过共振分析,得到了本级压气机叶片的共振频率,为相关叶片叶型设计、改进提供了参考依据。

The vibrational frequencies and cloud diagram of mode shapes analyzed and calculated for moving blades of gas turbines under the action of centrifugal-aerodynamic compounding force field play an important role in kinetic modeling of blades.In this paper,the models for moving blades and the three-dimensional models for flow field of a certain type of axial-flow compressor of a heavy-duty gas turbine under the action of the centrifugal-aerodynamic compounding force field are established respectively by the digital modeling and the fluid-solid coupling method.The velocity distribution of the flow field and the pressure distribution of the interior rotational wall,as well as the load distribution on the compressor blades are calculated by the definite boundary conditions and numerical calculation model of the flow field,and then the pre-stressed mode is analyzed.On above working basis,the stress distribution of blades under the action of the aerodynamic force field and the inherent frequencies of blades under the action of the centrifugal-aerodynamic compounding force field are analyzed.Besides,the resonant frequency of this stage of compressor blades is calculated by the resonance analysis,which provides a reference frame for design and improvement of the related blade profile.