Title:
MEASUREMENT OF FLOW SPEED DISTRIBUTION OF FLUID
Document Type and Number:
Japanese Patent JP3240595
Kind Code:
B2
Abstract:
PURPOSE: To measure the nonuniform flow speed distribution with high precision by adjusting the optical path length so that both polarized light mode joint is generated in each division and measuring the frequency of the envelope of the output side beat signal.
CONSTITUTION: A coupler 13 half divides the rectilinear polarized light of the Y polarized wave which is generated by polarizing 12 the laser beam, and one part is polarized 17 to an X polarized wave after an optical path length adjustor 15 L adjusts the optical path length. As for the other part, the frequency is shifted 16 to f+Δf, keeping the Y polarized wave constant, and both the polarized waves which are converged by a coupler 18 is inputted into a polarized wave conservative optical fiber 14. The propagation speed of the light differs, since each refractive index in the X and Y directions is different in the fiber 14. However, the optical path length difference of ΔL is provided, the optical path difference becomes 0 in a prescribed distance L, and interference is generated by the vibration lift, etc., of the Karman's vortex. The sensor part of the fiber 14 is fixed at a fixed point X for the flow speed distribution direction of each fluid in a prescribed interval. Accordingly, the flow speed can be measured by measuring the number of vibration of the Karman's vortex from the frequency of the envelope of the amplitude of the beat signal generated by the interference in each division, and the flow speed distribution can be measured.
Inventors:
Hiroshi Iitaka
Sojun Sato
Yoshikazu Murata
Hideaki Futashima
Sojun Sato
Yoshikazu Murata
Hideaki Futashima
Application Number:
JP11364892A
Publication Date:
December 17, 2001
Filing Date:
May 06, 1992
Export Citation:
Assignee:
National Institute of Advanced Industrial Science and Technology
Sumitomo Electric Industries, Ltd.
Sumitomo Electric Industries, Ltd.
International Classes:
G01F1/32; G01J1/00; G01P5/00; G01P5/02; G01P13/00; G01F1/00; (IPC1-7): G01F1/00; G01F1/32; G01P5/02; G01P13/00
Domestic Patent References:
| JP5180673A |
Attorney, Agent or Firm:
Bunji Kamata (2 outside)
Bunji Kamata (2 outside)
Bunji Kamata (2 outside)