Tomographic imaging of counter-current bubbly flow by wire mesh tomography

The objective of this work is to investigate characteristics of counter-current bubbly flow in a circular pipe with an inner diameter of 50 mm by using wire mesh tomography (WMT). The accuracy of WMT on void fraction measurement is also clarified by comparing the result with a non-intrusive optical method. The accuracy is within ±10%. Local void fractions of many flow conditions are reported. Local void fraction profile affected by superficial liquid velocity and bubble size is shown and discussed. Furthermore, intrusive effects, including bubble break-up and bubble deceleration, are also investigated. Bubbles passing a transparent wire mesh sensor (WMS) are investigated by the optical method. It is shown that bubbles are broken and decelerated by wires of the sensor. It can be concluded that the bubble break-up rate increase with increasing of bubble velocity. However, the bubble deceleration is not depending on the bubble velocity.