Abstract
An experimental investigation has been made regarding a turbulent structure of a horizontal channel flow with microbubbles. In the present study, we approached by two techniques, one is a Borescope-PIV, and another is a measurement using an optical shear stress sensor. In bubbly flow, the PIV measurement is hampered by existence of a large number of bubbles in optical path. It enables clear measurements of bubbles and liquid phase from closer distance by using the Borescope. For optical shear stress sensing, we have developed a new signal processing, which enables to measure in bubbly flow. The process classifies original signals into signals from tracers and microbubbles. The experiments have been carried out for flow conditions with Reynolds number ranging from 5,000 to 10,000 and void fraction up to 1.0%.
