U形管流体压强计的动态特性分析

Analysis on dynamic response of the U-tube flow manometer

对U形管流体压强计的动态特性进行分析,首先建立了U形管流体压强计的简化数学模型。在简化数学模型受力特性分析和非稳态管流等一系列假定条件的基础之上,利用牛顿定律和经典控制理论中的时域法,分析了层流和紊流状态的管壁切应力公式及紊流状态的能量损耗,并给出阶跃输入下的最大振幅和等价线性阻尼率公式。最后利用SIMULINK比较了非线性与线性流体压强计微分方程。

The dynamic response of the U-tube flow manometer is analyzed in the paper. Firslyt, the simplified mathematical model of the U-tube flow manometer is established. Then, based on the analysis of the stress characteristics of the simplified mathematical model and on a series of supposed premise such as unsteady pipe flow, using Newton＇s law and time-domain method of the classical control theory, the paper analyzes the wall shearing stress equation under laminar and turbulent flows and the energy dissipation under turbulent flow condition, and also gives the maximum size of step function input and the equation of equivalent hnear damping ratio. Lastly, the paper uses SIMULINK to the compare differences between the nonlinear and linear manometer differential equation.