Disks with two different dimensions were used to clarify the differences in final vortex structures generated by the change in disk acceleration time. The experiment results and calculated results of vortex structures...Disks with two different dimensions were used to clarify the differences in final vortex structures generated by the change in disk acceleration time. The experiment results and calculated results of vortex structures match when the disk thickness is 20 mm and the Reynolds number is 5000 - 15000. Also, they match when the disk thickness is 30 mm with a Reynolds number from 3000 - 5000 and 9000 - 20000. Even when the size of the disk and the Reynolds number are the same, the final vortex structures can be different due to differences in the disk acceleration time.展开更多
The flow structure around the intake of a vertical pump is investigated experimentally and numerically in order to obtain a guideline in designing the optimum shape of the intake of vertical pumps, in which their inst...The flow structure around the intake of a vertical pump is investigated experimentally and numerically in order to obtain a guideline in designing the optimum shape of the intake of vertical pumps, in which their installation area is demanded to be minimum without losing the high performance. We concentrate our attention on the expansion ratio of the intake as a representative characteristic of the shape of the pumps and investigate the effect of the expansion ratio on pump performance. It is concluded that the optimum expansion ratio ranges in 1.1-1.2 if we take into consideration that the area needed for the installation of the pump should be minimum.展开更多
文摘Disks with two different dimensions were used to clarify the differences in final vortex structures generated by the change in disk acceleration time. The experiment results and calculated results of vortex structures match when the disk thickness is 20 mm and the Reynolds number is 5000 - 15000. Also, they match when the disk thickness is 30 mm with a Reynolds number from 3000 - 5000 and 9000 - 20000. Even when the size of the disk and the Reynolds number are the same, the final vortex structures can be different due to differences in the disk acceleration time.
文摘The flow structure around the intake of a vertical pump is investigated experimentally and numerically in order to obtain a guideline in designing the optimum shape of the intake of vertical pumps, in which their installation area is demanded to be minimum without losing the high performance. We concentrate our attention on the expansion ratio of the intake as a representative characteristic of the shape of the pumps and investigate the effect of the expansion ratio on pump performance. It is concluded that the optimum expansion ratio ranges in 1.1-1.2 if we take into consideration that the area needed for the installation of the pump should be minimum.
