Quantitative analysis method for laminar-turbulence transition process of mechanical seal by a catastrophic model

Author(s):  
Yunlei Wang ◽  
Jiu Hui Wu ◽  
Lushuai Xu ◽  
Zhuo Zhou

Fluid flow regime has an important influence on the lubrication performance of mechanical seal. A novel method is proposed to analyze the flow regime transition quantitatively based on a cusp catastrophic model with dimensionless analysis. Furthermore, from this method, a turbulence transition factor is derived strictly to describe the turbulent transition process of mechanical seal, which is verified by the published results. Then this factor is applied to hydrodynamic lubrication mechanical seal to analyze the influence of flow regime on sealing performance. The results indicate that the performance parameters of mechanical seal are greatly influenced by the transition of fluid flow regime, and the stability of mechanical seal decreases in the transition to turbulent flow. The novel method of flow regime transition analysis provides a new insight into the turbulence model.

Author(s):  
Muhao Zhang ◽  
Liang-ming PAN ◽  
Peng Ju ◽  
Mamoru Ishii

In order to investigate the structure parameters evolution characteristics during flow regime transition process in slug flow, the vertical upward slug flow experiment in a wide range of liquid superficial velocity (0.03 < jl < 1.6 m/s) were conducted in a tubular test section with the inside diameter of 25.4 mm. Impedance void meters were employed to measure the void fraction of separated two parts corresponding to Taylor bubble and liquid slug. The present research studied the evolution of length ratio and void fraction in slug unit by keeping the liquid superficial velocity constant while increasing gas flow rate. New structure of slug unit in strong relation with transition process was observed. In specific, it was realized that the proportion of such special structure unit played an important role in transition from slug flow to churn-turbulent flow. The existing transition criteria from slug flow to churn-turbulent flow in upward two-phase flow (entrance effects model, flooding model, wake effects model, bubble coalescence model and Helmholtz instability model) were compared with the experimental identified results obtained by a new objective flow regime identification method, ReliefF-FCM algorithm. The results indicate that the transition model based on the wake effects could be the most appropriate choice to describe the mechanism of transition from slug flow to churn-turbulent flow in present experimental conditions.


2003 ◽  
Vol 125 (4) ◽  
pp. 544-544 ◽  
Author(s):  
Sang Young Son ◽  
Jeffrey S. Allen ◽  
Kenneth O. Kihm

2010 ◽  
Vol 43 (10) ◽  
pp. 829-832 ◽  
Author(s):  
Hiroaki Matsubara ◽  
Kiyoshi Naito ◽  
Hideharu Kuwamoto ◽  
Toshiyuki Sakaguchi

2003 ◽  
Vol 96 (1-3) ◽  
pp. 15-22 ◽  
Author(s):  
M.C. Ruzicka ◽  
J. Drahoš ◽  
P.C. Mena ◽  
J.A. Teixeira

2019 ◽  
Vol 145 (7) ◽  
pp. 06019004 ◽  
Author(s):  
Weichen Ren ◽  
Jianhua Wu ◽  
Fei Ma ◽  
Yu Zhou

Sign in / Sign up

Export Citation Format

Share Document