Analysis of annular flow disturbance wave frequency in two different installation conditions

The dynamic local liquid film thickness of annular flow was measured with a near infrared (NIR) equipment. Basing on the power spectral density (PSD) to analyze this signal, the frequency of disturbance wave was obtained. The experiment was carried out for both horizontal and vertical annular flow. Considering the effects of flow velocity and gas pressure, the results showed that the wave frequency increases with the increase of flow velocity and gas density in both installation conditions. For the numerical correlation, the frequencies of the vertical is more regular than those of the horizontal. (paper)