On The Investigation of Flow Rate Measurements Using Tap Noise and Variational Mode Decomposition

Resumo

Currently, conventional flow measurement methods are intrusive, and flow meters need to be installed
on pipelines conveying fluid. Some investigations have already been conducted to develop non-intrusive flow
measurement techniques, mainly via using vibro-acoustic signals acquired straight on the pipe, where the flow
induced vibration can be used to estimate the flow rate. However, such techniques are very accurate for high flow
rate values which are related to the level of vibration specially when the flow is turbulent. This is not the case
when considering tap noise vibration associated with the water flow, which is much smaller than for industrial
cases. Here, for tap noise, the induced vibration is measured in a valve next to the tap. Variational Mode
Decomposition Method is then used to give an estimation of the frequency bandwidth over which the tap noise
can be found. The signals are filtered out using such band to attenuate background noise to enhance the flow rate
estimation. This is conducted using classical vibration measures such as the RMS value and Power Spectral
Density for the time and frequency domain, respectively. Actual tap vibration signals were collected at different
flow rates by using two different accelerometers with different sensitivities to validate the methodology. It was
found that the methodology is effective in selecting the bandwidth over which induced vibration due to tap noise
is concentrated, and also estimating the flow rate for tap usage. The sensor sensitivity, however, indicates that for
low flow rates the higher the better for tap flow estimation.