This research paper describes an experimental method and the corresponding theory which enables the characterization of small viscoelastic pipes. The experimental set-up is a reservoir–pipeline–oscillating-valve configuration, where valve opening and pressure just upstream of the valve were measured. This allows the extraction of pressure amplitude and phase at this point. This configuration can be analytically modelled in the frequency domain with help of the impedance method. The viscoelastic behaviour of the pipe is modelled with a multi-element Kelvin–Voigt model whose moduli are estimated with a least squares method to fit the recorded complex-valued pressure data with the modelled one. Extracting amplitude and phase of the pressure signal is doubling the amount of data which can be used in the estimation algorithm. This and the use of an analytical model provides a robust and fast method to calibrate the viscoelastic properties of a pipe in the frequency domain.

中文翻译：

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基于相位和振幅的小粘弹性管道在频域中的表征，带有储层-管道-摆动阀系统

本研究论文描述了一种实验方法和相应的理论，可以表征小粘弹性管。实验装置是一种储液器-管道-振荡阀配置，其中测量了阀门上游的阀门开度和压力。这允许提取此时的压力幅度和相位。借助阻抗方法，可以在频域中对这种配置进行分析建模。管道的粘弹性行为用多元素 Kelvin-Voigt 模型建模，该模型的模量用最小二乘法估计，以将记录的复值压力数据与建模的数据拟合。提取压力信号的幅度和相位使可用于估计算法的数据量加倍。