Pipeline Transients with Frequency-Dependent Wavespeed

这一建议涉及管道系统中的非定常流体流动，其中波的传播速度是频率相关的，而不是恒定的。所提出的求解程序在频域中运行，其中已建立的频率响应和自由振动分析将被修改以分析包含与频率相关的波速的周期运动。此外，结合快速傅立叶变换的脉冲响应法将被用于非周期暂态情况的求解。将利用线性和非线性传递函数技术。线性和非线性脉冲响应方法为表现频率相关行为的软管和管道提供了一种有吸引力的替代方法。在许多依赖液压控制线路为机床、机器人、重型设备、运输车辆等上的执行器提供能量传输的行业中，应用程序非常多。在水电系统中，较长的石油、天然气和水输送管道以及隧道通常表现出频率相关的行为。本提案中的方法旨在为这些行业解决这些问题。

This proposal is concerned with unsteady fluid flow in pipeline systems in which the wave propagation velocity is frequency dependent, rather than constant. The proposed solution procedure operates in the frequency domain where well established frequency response and free vibration analyses will be modified to analyze periodic motions incorporating the frequency-dependent wavespeed. Additionally, the impulse response method, incorporating the Fast Fourier Transform, will be used in the solution of nonperiodic transient cases. Both linear and nonlinear transfer function techniques will be utilized. The linear and nonlinear impulse response method provides an attractive alternative for hoses, tubes and pipelines that display a frequency-dependent behavior. Applications are numerous in many industries that rely on hydraulic control lines to provide energy transmission to actuators on machine tools, robots, heavy equipment, transportation vehicles, etc. Long oil, gas, and water transmission pipelines, and tunnels in hydropower schemes often display a frequency-dependent behavior. The methods in this proposal are taylored to address these topics for these industries.