Study on connecting tube dynamics for transient pressure measurement

Abstract

The present study evaluates the dynamic response of connecting tubes for transient pressure measurement. A systematic study is conducted to quantify the amplitude and phase distortion of connecting tubes of diameter 1, 2 and 3�mm with different lengths (10�50�cm). The experimental measurements and theoretical predictions have been carried out with both air and water as the working medium to cover a wide range of frequencies. The study highlights the underdamped nature of all the systems studied. The natural frequency of the system increases with an increase in the tube diameter and a decrease in tube length. The difference in natural frequency obtained from the experimental results and theoretical prediction is less for the smaller tube diameter (d = 1�mm) and more pronounced for the larger tube diameter. Larger tube diameters are recommended to avoid amplitude and phase distortion errors, especially in the low-frequency range. However, resonance effects are more pronounced for larger tube diameters. The phase response of larger tube diameters remains close to zero over a large range of frequency (0�0.8 times the natural frequency); hence, this range is more suitable for applications where phase information is more important than amplitude. This study is useful for compensating the amplitude and phase distortion error encountered in transient pressure measurements. � 2020, Indian Academy of Sciences.