Experimental study of microbubble drag reduction on an axisymmetric body

• DOI: 10.1142/s0217984918500355
• Publication Date: 2018-01-10T03:42:38Z
• Authors: Wuchao Song; Cong Wang; Yingjie Wei; Xiaoshi Zhang; Wei Wang
• Keywords: Water tunnel

Microbubble drag reduction on the axisymmetric body is experimentally investigated in turbulent water tunnel. Microbubbles are created by injecting compressed air through porous medium with various average pore sizes. The morphology of microbubble flow and size distribution observed high-speed visualization system. Drag measurements obtained balance which presented as function void ratio. results show that when injection rate high, uniformly dispersed coalesced into an layer larger increment diameter distributions under conditions submitted to normal distribution. can be divided three distinguishable regions ratio experiences increase stage, rapid stage stability respectively, corresponding morphologies flow. Moreover, increases decreasing sizes at identical area low speeds, while effect reduced gradually until it disappears increasing free stream indicates smaller microbubbles have better efficiency reduction. This research help improve understanding provides helpful references for practical applications.