Numerical study on the flow in balancing hole

29th IAHR Symposium on Hydraulic Machinery and Systems

Matsui, Jun^1 ; Okubo, Atsushi^1 ; Yamashita, Yousuke^1

Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokhama, Japan^1

关键词: CFD simulations;    Discharge coefficients;    Flow situation;    Rotating speed;    Rotational speed;    S-shaped;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/2/022002/pdf
DOI  :  10.1088/1755-1315/240/2/022002

来源: IOP

【 摘 要 】

In order to investigate the value of discharge coefficient of balancing hole Cd for wide range of axial flow velocity v in the hole and rotational speed u, series of CFD simulations are made. Some of the result agrees well with the existing experimental data, but the difference is about 20% in some cases with high Rev. Also, for wide area of Rev, the effect of rotating speed u becomes significant. So it is considered that the parameter v/u is a dominant indicator of Cd. Furthermore, for very low range of v/u, we found a rare flow situation with S-shaped streamlines. In this flow, pumping of disk is so strong and Cd may differ largely.