换热管受湍流分布力随机振动的虚拟激励法  

Pseudo-excitation method for random vibrations of a heat exchanger tube subjected to turbulent cross-flows

作　　者：张琦 张新玉[1,2] 张文平 ZHANG Qi;ZHANG Xinyu;ZHANG Wenping(College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001, China;Research Institute of Power Engineering Technology, Harbin Engineering University, Harbin 150001, China)

机构地区：[1]哈尔滨工程大学动力与能源工程学院,黑龙江哈尔滨150001 [2]哈尔滨工程大学动力装置工程技术研究所,黑龙江哈尔滨150001

出　　处：《哈尔滨工程大学学报》2021年第12期1739-1747,共9页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51579051).

摘　　要：为了分析换热管受外部横向湍流激励作用下的随机振动响应,本文建立了密置错排管束绕流的三维计算流体力学模型。应用大涡模拟湍流方法对管束绕流场进行了仿真,对换热管表面升、阻力进行了时域内和频域内的分析。经过多次计算提取流场深处圆管的表面湍流分布力,将换热管简化为两端固支中间简支的线性梁模型,引入虚拟激励法计算换热管随机振动的功率谱,并与传统随机振动预报方法对比了计算效率和精度。计算结果表明湍流分布力为服从均匀分布的广义多点随机过程,不同方法的计算速度呈模态截断阶数的指数关系,并通过精度分析验证了相干性各异的载荷作用时不同频段内虚拟激励法的精度与精确算法极为接近。To analyze the random vibration response of a heat exchanger tube excited by external transverse turbulence,a three-dimensional(3D)computational fluid dynamics model of a flow across densely packed staggered tube bundles is established in this study.The flow field is simulated using the large eddy simulation turbulence method,and the analyses of the lift and drag forces on the surface of the tube bundle are performed in the time and frequency domains.After several calculations,the distributed turbulent force on the circular tube deep in the flow field is extracted,and a linear beam model with fixed ends and simple support in the middle is simplified from the heat exchanger tube.The pseudo-excitation method is introduced to calculate the power spectrum of the heat exchanger tube random vibration,and its calculation efficiency and accuracy are compared with those of the traditional random vibration prediction method.The calculation results indicate that the distributed force is a generalized stationary multi-point random process of uniform distribution and that the calculation speed of different methods shows an exponential relationship with the modal truncation order.The accuracy analysis results verify that the accuracy of the pseudo-excitation method in different frequency bands is very close to that of an accurate algorithm under the action of loads with different coherences.

关 键 词：换热器 管束 绕流仿真 计算流体力学 分布流体力 湍流抖振 随机过程 随机振动 虚拟激励法 

分 类 号：O324[理学—一般力学与力学基础]