Development of a Device for Measuring Air-Water Flow Characteristics

Air-water flow is a complex and challenging subject in many engineering fields as well as hydraulic engineering; and discovery of its characteristics can help the engineers to predict and analyze a probable phenomenon. In the present paper, development of a device capable of measuring the flow velocity, air concentration, diameter and counts of bubbles in air-water flows is described. The heart of the present device is two resistive probes with a novel configuration. Being pressure and corrosion resistant and also having negligible resistivity in the flow are some of the unique features of the employed needles. Moreover, sampling frequency and time can be adjusted for the intended application by the user. In the present electronic board, maximum available sampling frequency is in the order of KHz, while the duration of sampling is not limited. The circuit design considers avoiding the polarization of the probe tip. Increasing the number of probes up to four which can operate simultaneously with no change in the electronic board is another advantage of the proposed device that can be useful for more complex flows. Different tests for verification of the device accuracy have been performed and good results were reported for measurements.