記述言語：日本語   出版者・発行元：一般社団法人 ターボ機械協会  

DOI： 10.11458/tsj.52.2_83

CiNii Research

記述言語：英語   出版者・発行元：一般社団法人 日本機械学会  

In the present study, numerical simulation of cavitating flow using Multi-Process model, which is one of the homogeneous cavitation models and consists of multiple transport equations of bubbly flow characteristics defined on the basis of the moment method, is conducted for a centrifugal pump toward more accurate prediction. The experiment is also conducted for the same pump to obtain the hydraulic performance including the axial thrust force characteristics as well as the visual aspects of cavitation for the validation of numerical simulation. It is found that the present simulation can qualitatively reproduce the degradation of pump suction performance as well as the change in axial thrust force under cavitation at the design flow rate; thrust forces acting on the impeller and the balance drum decreases with the head drop. The cavity patterns leading to the head drop are also well reproduced; the cavitation on the suction surface extends into the blade passage. At a partial flow rate close to the design one, the simulated cavity patterns with the inception and moderate states of cavitation agree with the observation, but they are not well reproduced perhaps due to the insufficient mesh resolution at the deep partial flow rate where the most of cavitation occurs in the vortical structure, typically in the tip separation vortex.

DOI： 10.1299/jfst.2024jfst0011

Web of Science

Scopus

CiNii Research

出版者・発行元：Journal of Physics: Conference Series  

In this study, in order to understand the relation between the diffuser rotating stall and the fluctuating radial thrust, unsteady RANS simulation of a centrifugal pump was carried out. The rotating stall with single stall cell was qualitatively reproduced though the propagation speed was smaller than the experiment. The pressure amplitude caused by the rotating stall was comparable to the measured one, and the tendency that the propagation speed increases as the flow rate increases agreed with experiment. The radial thrust fluctuation due to the rotating stall was well evaluated by the simulation, and a considerable difference of phase angle between the stall cell position and the working direction of radial thrust was detected, which also agreed with experiment. On the basis of simulation result, the reason is found to be that the radial force acting on the impeller external wall at the liner ring section due to stall cell was not very small but comparable to that acting on the impeller blade and outer wall, while their working directions were roughly 100° different. This suggests that considering the leakage flow in numerical simulation is important to accurately predict the radial forces generated by rotating stall.

DOI： 10.1088/1742-6596/2217/1/012031

Scopus

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmefed.2022.os07-24

CiNii Research