|Budget Amount *help
¥3,100,000 (Direct Cost : ¥3,100,000)
Fiscal Year 1998 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1997 : ¥2,600,000 (Direct Cost : ¥2,600,000)
Thin plates produced by a strip continuous casting method have sometimes curvatures and cracks so that waves on free surface of molten metal flow must be reduced as little as possible.
Although molten metal and water have quite different freezing point, both velocity and temperature boundary layer thicknesses are very thin in comparison with the depth, clarified in our past experimental and computational research. This means that the breaking out of waves on a free surface is the phenomenon in the potential flow region in the shallow flow.
This research, therefore, was started on a shallow water flow on a rotating circular cylinder, instead of molten metal flow.
This instability phenomena is due to external force, depending on the radius of curvature of free surface, angular position, density and surface tension of water, water velocity, and acceleration of gravity, and so on.
With simple approximations, the relation of wave length to angular position on a circular cylinder at which the free surface is stable was obtained.
On the other hand, the relation of wave length to angular position on the shallow water flow on a circular cylinder was determined experimentally.
The measurement of the order of magnitude of wave height of one hundredth mm was extremely difficult. The result is, however, fairly highly accurate.
The results of the theoretical prediction and the experiment agreed with each other very well.