ポンプ吸込水槽における渦発生条件の相似性

抄録

Three model pump sumps with geometrical similarity are constructed to study the similarity law in the flow of pump sump.Changing the flow rate and water height,the critical submergences for both air entraining vortex and submerged vortex are measured in each sump.For the air entraining vortex, there are two limits of critical submergence,one is proportional to the flow rate or velocity at bell inlet,the other is almost independent from flow rate.The former is mainly under the effect of Froude number,but the similarity on later limit is not clear.For the submerged vortex, the critical line is not clear in the smallest model.The power coefficient, n, for the similarity law estimated from above limits becomes between the same velocity case (n=0) and the same Reynolds number (n=1), both for the air-entraining vortex and for the submerged vortex.