塔振动与卡曼旋涡的解决办法

近几十年来,塔振动的事故便频繁发生。当旋涡的频率等于或接近塔设备固有频率,便会产生共振,这便是风诱发的振动。在进行工程结构设计时,事先估计到卡曼旋涡诱发振动的可能性,将有助于我们避免恶性事故的发生。

管壳式换热器声振动探析

综述了管壳式换热器发生声振动的原因及在设计上应采取的哪些措施进行解决

涡街流量传感器的新探索

本文对一种新型旋涡敏感元件的设计原理和使用效果作了简单的介绍。这种敏感元件采取升力型的信号拾取方式，使涡街流量传感器在管道完全没有可动部件，从而避免了市场上同类产品中存在的某些问题；同时新的设计方案也为压电型涡街流量传感器的信号拾取方式开辟了一条新的思路。

让我们看风云雷电

几年前，曾经有一部风云电影，名字就叫《风云》，我们借这个名字用一下，因为这次要谈的确实就是风云，当然还要加上一个雷电。在夏日里，风、云、雷电都是十分常见的天气现象。这些现象，有些是人们喜爱的，比如傍晚的和风，而有些又是令人恐惧甚至是憎恶的，比如台风和龙卷风。之所以会有如此大的区别，是因为人们处在它们的笼罩下，或是受着它们的恩惠，或是被它们放肆地折磨。但是，如果跳出“恩怨情仇”，单就形状而言，它们也有令人着迷的身姿。

Kinematics and forces of a flexible body in Karman vortex street

Experiments of a flexible filament in the wake of a cylinder and in free stream were conducted in a vertical soap film tunnel. The experiments distinctly visualized the movement of the filament. Based on the experimental kinematic results, a 2-d panel method was used to calculate the forces acting on the filament. The experiment and numerical results revealed that different from that in free stream, the filament in Karman vortex street flapped at the same frequency as the vortex street, and with smaller amplitude and larger curvature. The filament suffered an evident thrust in Karman vortex street, while a drag appeared in the case of free stream. The dependence of the drag coefficient on the phase relation between the movement of the filament and the Karman vortex street was also studied.