We investigate the characteristics of the transition from laminar to turbulent flow in the microtube with a diameter of 310μm. The microscopic particle image velocimetry is used to measure the water flow at Re =1600-...We investigate the characteristics of the transition from laminar to turbulent flow in the microtube with a diameter of 310μm. The microscopic particle image velocimetry is used to measure the water flow at Re =1600-2500 in the microtube. It is found that the flow transition occurs at Re=1600-1900, and the streamwise streaks and vortices appear in the transitional flow fields. These experimental observations provide a validation for the theoretical prediction of unstable travelling waves in pipe flow.展开更多
基金Supported by the National Natural Science Foundation of China with Grant No 10272066.
文摘We investigate the characteristics of the transition from laminar to turbulent flow in the microtube with a diameter of 310μm. The microscopic particle image velocimetry is used to measure the water flow at Re =1600-2500 in the microtube. It is found that the flow transition occurs at Re=1600-1900, and the streamwise streaks and vortices appear in the transitional flow fields. These experimental observations provide a validation for the theoretical prediction of unstable travelling waves in pipe flow.
