CAJ | 학술논문

运用FEM＼BEM声振耦合计算方法分析叶片出口角对离心泵在水动力激励下泵壳振动辐射噪声影响。采用大涡模拟方法模拟离心泵内部瞬态流场，获得蜗壳壁面偶极子声源；对泵壳体结构进行模态分析获得结构模态响应；利用LMS Virtual Lab间接边界元IBEM声振耦合模块计算非定常流动引起的离心泵内部噪声，并与实验数据对比，验证基于LES、声振耦合的噪声数值模拟方法可行性。计算离心泵外场噪声及声辐射，研究叶片出口角度对离心泵外场噪声辐射影响。结果表明，离心泵叶片通过频率BPF处的辐射声功率随叶片出口角的增大而增大；外场噪声声压级指向性分布显示叶片出口角存在合适范围，使泵在小流量工况运行时噪声较小。
운용FEM＼BEM성진우합계산방법분석협편출구각대리심빙재수동력격려하빙각진동복사조성영향。채용대와모의방법모의리심빙내부순태류장，획득와각벽면우겁자성원；대빙각체결구진행모태분석획득결구모태향응；이용LMS Virtual Lab간접변계원IBEM성진우합모괴계산비정상류동인기적리심빙내부조성，병여실험수거대비，험증기우LES、성진우합적조성수치모의방법가행성。계산리심빙외장조성급성복사，연구협편출구각도대리심빙외장조성복사영향。결과표명，리심빙협편통과빈솔BPF처적복사성공솔수협편출구각적증대이증대；외장조성성압급지향성분포현시협편출구각존재합괄범위，사빙재소류량공황운행시조성교소。
The FEM\BEM acoustic-vibro-coupling method was applied to study the effect of blade outlet angle on centrifugal pump noise caused by hydrodynamic forces.The large eddy simulation (LES)method was used to solve the transient flow field of the pump,and the volute surface dipole was obtained.The modes of the pump housing structure were analyzed using the finite element method (FEM).The acoustic-vibro-coupling module of the Virtual Lab software was employed to study the interior sound field of the pump caused by unsteady flow.By comparing the computational results with experimental ones,the method of LES combined with FEM\BEM for centrifugal pump noise computation was verified.On this basis,the outer sound fields were investigated,and the effect of blade outlet angle on outer sound fields was studied.The results show that the sound power at the blade passing frequency (BPF)becomes large as the blade outlet angle increases and the blade outlet angle should be at suitable range to ensure a lower noise level at low flow rates.