Optical flow rate measurement using unsteady pressures
US6536291B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1999 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Jul 2, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/712
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fiber optic strain gauge based flow rate measurement system includes two measurement regions located an average axial distance &Dgr;X apart along the pipe, the first measurement region having two fiber optic strain gauges located a distance X1 apart, and the second measurement region having two other fiber optic strain gauges located a distance X2 apart, each capable of measuring the unsteady pressure in the pipe 12. Signals from each pair of fiber optic strain gauges are differenced by summers to form spatial wavelength filters. Each spatial filter filters out acoustic pressure disturbances Pacoustic and other long wavelength pressure disturbances in the pipe and passes short-wavelength low-frequency vortical pressure disturbances Pvortical associated with the vortical flow field. The spatial filters provide signals to band pass filters that filter out high frequency signals. The Pvortical-dominated filtered signals from the two sensing regions are cross-correlated to determine a time delay &tgr; between the two sensing locations which is divided into the distance &Dgr;X to obtain a convection velocity Uc(t) that is related to an average flow rate of the fluid (i.e., one or more…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.