The complete artificial kidney is still not realized but for the partial treatment named hemodialysis. In the treatment, which should be taken almost every two days, excess water and solutes are removed through the extracorporeal blood flow. The removal rate in 4 hours treatment, instead of full duty of 48 hours in normal kidney, has enough initiative to introduce a chaos in mysterious equivalence of homeostasis. The most attractive, but only for the healthy hydraulist, phenomenon occurs when the blood volume is reduced to an extent beyond the stability criterion for the blood pressure regulation. Its depression is sometimes mortal, nevertheless it happens suddenly and shows a remarkable contrast to slow transitions in almost every measurable factors. The roles of hydraulist, even when focused only on this cardiac crisis, are heartily reserved as, for example, measurement of blood flow, analysis of its pressure flow relation in cardio vessel system, prediction and prevention of blood flow reduction, etc. The must in the other, rather engineering but still bloody, extreme is flow analysis in hollow fiber bundles, called dialyzer which is still obeyed with remarkable dead spaces.

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In order to get high Reynolds number flows in a wind tunnel, it is the best way to use a gas of small kinematic viscosity by making temperature lower and pressure higher in the closed wind tunnel. About 20 of cryogenic wind tunnels are being used in the world. In this report, at first, its principle, structure and characteristics are described. Then a look of several representative ones in the world are given. The status of researches using cryogenic wind tunnels are also described.

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The purpose of this study is to clarify the nonsteady aspects of mixing and ignition of hydrogen jets injected into air heated by rapid compression. A numerical model for hydrogen jets undergoing chemical reaction is developed on the basis of experimental findings. For calculation, the axisymmetric compressible Navier-Stokes equations considering a simplified reaction model and the explicit turbulence effect, which is represented by the k-ε two-equation model, is discretized by the explicit MacCormack method and the Flux-Corrected Transports technique.
General Patterns of the computed density distribution of the jet agree well with the corresponding experimental results deduced from Schliern photographs. When the initial air temperature is between 1200K and 1400K, the ignition time measured by the rapid increasing of the temperature and the amount of water production in the computation are generally consistent with that of hydrogen jets in the experiments. The ignition point and its tendency depend on the initial air temperature; for high air temperature (1400-1300K), the ignition point is near the spurting hole and the ignition tendency is diffusive, and as the temperature goes down lower (1200-1100K), the point moves far from the spurting hole and the tendency is pre-mixed.

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Instantaneous three-dimensional velocity fields in the wake of a hemisphere located on an open channel bed are measured by using flow visualization in multi-section and Mass-Consistent model. Instantaneous three-dimensional forms of the coherent structure at high Reynolds number are shown by three-dimensional vorticity vectors. The large vortex in the wake is similar to the hairpin vortex, which can be observed in a hemisphere wake at low Reynolds number. However, the long legs of hairpin in the streamwise direction at low Reynolds number are not observed. The secondary hairpin vortex has been generated on the upstream side of the large hairpin vortex and coalesced into the large hairpin. The instantaneous pictures of the coherent structure are taken at short time interval and their behaviors are investigated. The flow patterns induced by the large hairpin vortices are also examined.

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Tandem-Type WIG is recognized as a suitable layout for Rail-Way-Type WIG transportation system and other WIG crafts, because of its stability performance. Two aerofoil models, each of them having the same configuration are arranged as a tandem shape WIG and tested in the Low Turbulence Wind Tunnel with the fixed ground plate method at The Institute of Fluid Science, Tohoku University. Angle of attack and clearance height between the trailing edge and the ground plate are varied independently. Influence of the existence of forward WIG and the effect of change in it's ground clearance, and angle of attack to the Rear WIG aerodynamic characteristics are reported.

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