Abstract:

The apparatuses of measuring method of flow velocity based on distributed optical fiber sensing technology are introduced briefly. By studying the heat-transfer process between optical fiber and running water, the theoretical equation of the method about flow velocity, stable temperature rise of optical fiber, heating power and other parameters is deduced. Model test is designed. And temperature rise tests of different flow velocity and heating power are carried out. Based on test data, temperature rise rules of still water and running water are compared. The results indicate: all curves of temperature rise compose of two stages, and the temperature rise in still water is higher than that in running water, and the temperature difference becomes greater with flow velocity and heating power. The effect of heating power on temperature rise of still water and running water is studied; and it is found that the stable temperature rise in still water has linear relationship with heating power. Stable temperature rise of optical fiber has nonlinear inverse relationship with flow velocity. At last, this method is discussed; and further study advice is put forward.

Key words: distributed optical fiber sensing technology, flow velocity, temperature rise, heating power