用于多级压气机非定常流动的谐波平衡方法研究

Investigation on Harmonic Balance Method for Simulation of Unsteady Flow in the Multi-Stage Compressor

关键词:  轴流压气机  非定常流动  谐波平衡法  相滞后法

Key words:  Axial compressor  Unsteady flow  Harmonic balance method  Phase lag method

摘要:

为了在保证计算精度的同时，进一步提高压气机流动非定常模拟的计算效率，在课题组自行开发的结构化有限体积解算器上实现了谐波平衡法。以1-1/2级轴流压气机为研究对象，采用谐波平衡法和相滞后法对其非定常流场进行了数值模拟，并采用谐波平衡法对该压气机的时序效应进行了初步研究。计算表明，随着谐波阶数的增加，谐波平衡法的计算结果逐渐接近于相滞后法的计算结果；在谐波阶数达到5阶以后，谐波平衡法的计算结果不再随谐波阶数的增加而变化，且与相滞后法的计算结果匹配；谐波平衡法在保证与相滞后法相同的计算精度的情况下，计算效率相比相滞后法高了近3倍；5阶谐波平衡法即可很好地模拟入口导叶-静叶时序效应。算例表明，谐波平衡法相比相滞后法具有更多的选择空间和更高的计算效率。

Abstract:

In order to improve the simulational efficiency of the unsteady flow in the axial compressor without lossing the computational accuracy，the harmonic balance method were implemented into an in-house finite volume code. Taking a 1-1/2 stage axial compressor as an example，results of the harmonic balance method and the phase lag method were compared. The clocking effect of the compressor was also analysed using the harmonic balance method. The simulational results indicate that，the simulational result of the harmonic balance method grows closer to the phase lag method as the harmonic order of the harmonic balance method increases. When the harmonic order is set more or equal to 5，the computational result does not vary with the harmonic order and matches well with the computational result of the phase lag method. The harmonic balance method is as precise as the phase lag method with a factor of 3 speed-up. The harmonic balance method with the harmonic order of 5 can simulate the IGV-S1 clocking effect well. The results demonstrate that，compared with the phase lag method，the harmonic balance method has more computational options and higher computational efficiency.