In this paper, the flowfield similar to that in a dump type of combustion chamber is investigated using flow visualization techniques. The parameters which have been varied are the dump angle, the Reynolds number, the position of the dump and the inlet width. These are varied systematically to determine their influence individually. It is found that the dump angle is the most important parameter for this type of flow. The Reynolds number has also considerable influence on the flowfield, but the other parameters appear to have very little influence.

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Flow fields around a Savonius rotor with and without a rotation are studied by flowvisualization experiment with the smoke-wire method. In case of the rotating rotor, the tip speed ratio is set at the maximum power performance. Based on the variations of the flow-pattern with and without a rotation, and with a rotor angle, the effect of the rotor rotaion is discussed in ralation to its power performance. It is found that at small rotor angles Coanda like flows are formed on the convex side of an advancing rotor, and as the angle increases large circulating vortices are shed downstream from both the sides of the rotor. Such Coanda like flows prompt a rotor rotation though the vortices act inversely.

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This paper describes interaction of vortex rings, whose number ranges 3 to 20, travelling along a common axis. A train of rings were produced by using a computer-aided plunger drive, whose apparatus made generation of each vortices controllable in principle.
Smoke visualization method was utilized, and the motion of vortices was analyzed. The results were compared with those based on perfect fluid theory.
Several specific features of the interactions were clarified; especially, it was found that the merging location of two vortices was jittering in space, and its feature was quite different from that of the theory. Finally, the problems involved in the apparatus were pointed out.

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