(3) Compared with the “parallel passage”, the “series passage” can make the pressure drop more efficiently. The main function of the “series passage” is for the pressure dropping while the “parallel pass- age” is mainly responsible for the flow-rate regula- tion.

(4) The tortuous labyrinth passage consists of a series of right angle turns and expanding passages, to form a large number of stages. It makes the  pressure of the fluid drop in a downwards serrated  way with the pressure higher than the saturate vapor pressure.

Acknowledgement

The authors also wish to express their apprecia- tion to Mr. Li Hai in SEC-KSB Nuclear Pumps and Valves and Mr. Zhou Qing-li in State Nuclear Power Technology Corporation (China).

References

[1] WU J., YUTTURKAR Y. and SHYY W. Assessment of modeling strategies for cavitating flow around a hydro- foil[C]. Fifth nternational Symposium on Cavitation. Osaka, Japan, 2003.

[2] BAN Wei, TAO Guo-liang and LU Bo et al. The modeling research and the characteristics analysis of new type of pneumatic proportional pressure valve[J]. Journal of Zhejiang University (Engineering Science), 2012, 46(11): 1953-1959(in Chinese).

[3] XIAO Fang, WANG Ya-zhou and DIAO An-na et al. The optimization of labyrinth seal structure based on FLUENT software  technology[J].  Fluid  Machinery,  2013, 41(9):

29- 32(in Chinese).

[4] LI Zi-qin, MA Jing. The water flow experiment of  abyri- nth  emitter[J].  Transations  of  the  Chinese  Society of

Agricultural Engineering, 2012, 28(1): 82-86(in Chinese).

[5] JOHANSEN S. T., WU J. and SHYY W. Filter-based unsteady RANS computations[J]. International Journal of Heat and Fluid Flow, 2004. 25(1): 10-21.

[6]   PANDEY G. K., RAMDASU D. and PADMAKUMAR G.

et al. Development of honeycomb type orifices for flow zoning in PFBR[J]. Nuclear Engineering and Design, 2013, 262: 63-71.

[7] SENOCAK I., SHYY W. A pressure-based method for turbulent cavitating flow computations[J]. Journal of Computational Physics, 2002, 176(2): 363-383.

[8]   WU D., BURTON R. and SCHOENAU G. et al. Mode-

lling of orifice flow rate at very small openings[J]. Inter- national Journal of Fluid Power, 2003, 4(1): 31-39.

[9]   ABOU EL-AZM ALY A., CHONG A. and  NICOLLEAU

F. et al. Experimental study of the pressure drop after fractal-shaped orifices in turbulent pipe flows[J]. Experi- mental Thermal and Fluid Science, 2010, 34(1): 104- 111.

[10]  JANKOWSKI T. A., SCHMIERER E. N. and PRENGER

F. C. et al. A series pressure drop representation for flow through orifice tubes[J]. Journal of Fluids Engineering, 2008, 130(5): 589-603.

[11] ZHONG Fang-sheng. Study on the flow characteristic of valves for boiler feed pump recirculation[D]. Master Thesis, Shanghai, China: University of Shanghai for Scie- nce and Technology, 2008(in Chinese).

[12] WANG H., XIE S and SAI Q. et al. Experiment study on pressure drop of a multistage letdown orifice tube[J]. Nu- clear Engineering and Design, 2013, 265: 633-638.

摘要：迷宫通道由高压控制阀盘片的一系列直角转弯组成。在本文中，对该通道中的速度和压力分布进行了数值模拟。显示“串联通道”可以更有效地降压。“串联通道”的主要功能是降压，而“并联通道”主要功能是调节流量。随着流体流过横截面，经过一系列减压和膨胀，压力也将会下降和部分恢复，这被称为多级压降。通过这种方式，可以在迷宫通道中的任何地方将速度控制在合理的水平。随着流体压力以锯齿状下降，压力高于局部饱和蒸汽压力，因此，相变不会诱发空化。论文网