| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2006: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
Chaotic mixing method and its application to the filtration system for solid-1iquid multipnase flow
The main vortex mode with the extra smaller vortex has occurred at the aspect ratio (Γ) of 1.0 and the radius ratio(η)of 0.375 under the rigid boundary layer (Ekman boundary layer), which exists near the vertical boundary ends. This vortex keeps its original shape even in the high Reynolds number (Re) of 20,000 in the region of the turbulence. In the filtration system with Γ=3 and η=0.375, the nylon particle (mean diameter is about 80 μm and the specific gravity of 1.2) is used, and at Re=0, most particle is accumulated on the filter surface in a few minutes, but the pressure drop is confirmed to keep in lower level when the rotating Re is increased. This fact shows the clear effect on reducing the pressure drop of the filtration process. However, the pulsating suction of the flow would sometimes cause the instability in filtration, which is not clarified yet.
Cultivation of microorganism
… More
With Taylor vortex flow
Since it is difficult to use a blood cell directly in the engineering laboratory, the similar vegetable photosynthesis microorganisms are used and the fluid dynamic effect on cultivation by the Taylor vortex is investigated at Γ=1. As for the actual size, the diameter of the inner cylinder is 28mm, and the one of the outer 75mm, are selected respectively. The cultivation time is about ten days. As the result, a specific growth rate (p) increases with the increase of Re. But in the very limited region of 6000<Re<8250, μ takes a steep sloop, and after then, it turns to sharp decline in 8250<Re<9600. In Re>9600, μ increases again with a gentle gradient curve. p shows the maximum value at Re=8250, but not becomes the same value at Re=18000, although the sedimentation rate is same at Re=18000 as Re=8250. This fact indicates the flow structure is different between both Reynolds numbers. This flow pattern is measured using Ultrasound Doppler Profiler and shows the averaged velocity profiles are quite different between Re=8000 and 26000. Each flow is more turbulent, but it is well observed that the flow at Re=8000 has one vortex with an extra vortex in the bottom region and the one at Re=26000 has pair vortices in upper and lower regions. This difference would influence the specific growth rate. In this reactor, Spirulina is alive until Re=40000 without disturbing from the share flow. Less
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