Email Alerts
RSS
Sectioning test study on valve top gap cavitation of high-head lock
-
摘要: 针对日益严峻的高水头单级船闸阀门顶缝空化问题，采用能够真实反映缝隙流特性的1:1切片模型试验，研究阀门顶缝空化特性及门楣自然通气防空化机理。研究表明，随着空化的发展，缝隙段依次发生喉口跌坎空化、主流中心空化和阀门面板空化，缝隙段负压区不断延伸，直至整个缝隙段达到稳定的-10 m水柱负压，压力脉动很小；门楣自然通气通过增加缝隙段压力，消除主流中心空化和阀门面板空化，抑制喉口跌坎空化。当采用门楣自然通气措施后，缝隙段压力稳定在-2 m水柱左右，空化消失，缝隙段水流脉动压力增大；缝隙段压力与单宽通气量近似二次多项式关系，通气量极值对应的缝隙段压力约-2 m水柱，此时缝隙段压力与通气量达到平衡状态，当缝隙段压力逐渐升高时，门楣通气量逐渐降低，直至自然通气停止。Abstract: In view of the developing problem of the valve top gap cavitation of high head single-lift ship lock, the scale 1:1 sectioning model test method which can truly describe the gap flow characteristics is adopted to study the valve top gap cavitation and the cavitation resistance mechanics of the natural aeration. It is found that three kinds of cavitation, namely the throat cavitation, the flow center cavitation and the valve plate cavitation, are taking place step by step in the gap section with the development of the cavitation. The mechanics of the natural aeration measure to prevent cavitation is that the pressure of the gap flow becomes high when the air is aerated into the gap section, and then the flow center cavitation and valve plate cavitation disappear and the throat cavitation is weakened remarkably. With the growing of the cavitation, the negative pressure zone in the gap section is gradually extending until the gap section is fulfilled with stable -10 m water head negative pressure. When the natural aeration measure is employed, the pressure in the gap section is stable in the -2 m water column and the cavitations disappear. It is nearly a quadratic polynomial relationship between the pressure of the gap section and the ventilation per meter width. The pressure of the gap is -2 m water head when the ventilation goes to the extreme value, which is the limiting equilibrium situation for the natural aeration system. When the pressure of the gap gradually increases, the ventilation volume decreases gradually until the cessation of the natural aeration. The research results are benefitcial to the cavitation resistance design of the high head valve.
-
Key words:
- high head lock /
- valve /
- top gap cavitation /
- natural aeration /
- sectioning test
-
图 3 不掺气与掺气流态对比
Figure 3. Flow pattern comparison between natural aeration and non-aeration
图 4 空化发展过程缝隙段压力变化(单位：m水柱)
Figure 4. Pressure changes with growing of cavtitation in gap section (unit : m in water column)
图 5 缝隙段压力分布(单位：m水柱)
Figure 5. Pressure distribution along gap section (unit: m in water column)
图 6 门楣通气与否空化噪声对比
Figure 6. Cavitation noise comparison with and without natural aeration
图 8 不同开度缝隙段时均压力分布(单位：m水柱)
Figure 8. Pressure distribution on valve plate under different openings (unit: m in water column)
图 9 单宽通气量与缝隙段压力关系
Figure 9. Relationships between ventilation and pressure of gap section
表 1 门楣通气与否振动对比
Table 1. Vibration comparison with and without natural aeration
喉口宽度/mm 方向 振动加速度均方根值/(m·s-2) 降幅/% 不通气 通气 20 x 1.65 0.49 70.5 y 1.69 0.35 79.5 z 2.28 0.55 75.8 25 x 1.88 0.58 69.2 y 1.94 0.45 76.7 z 2.85 0.73 74.6 
下载: 导出CSV
-
[1] 胡亚安, 郑楚珮, 凌国增.高水头船闸反弧形阀门门顶缝隙流特性及其应用[J].水利水运科学研究, 1995(4): 352-361. http://www.cnki.com.cn/Article/CJFDTOTAL-SLSY504.003.htm HU Ya'an, ZHENG Chupei, LIN Guozeng. Characteristics and applications of top gap slit flow at reversed tainter valve on lock with high lift[J]. Journal of Nanjing Hydraulic Research Institute, 1995(4): 352-361. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-SLSY504.003.htm [2] 卞兆盛.葛洲坝船闸输水阀门段空化与声振研究[J].水运工程, 2000(7): 34-37. http://www.cnki.com.cn/Article/CJFDTOTAL-SYGC200007007.htm BIAN Zhaosheng. A study of cavitation and acoustic shock at water filling & emptying valve section of Gezhouba ship lock[J]. Port & Waterway Engineering, 2000(7): 34-37. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-SYGC200007007.htm [3] 蒋筱民, 宋志忠.高水头船闸阀门段廊道防空化设计[J].人民长江, 2009, 40(23): 51-53. doi: 10.3969/j.issn.1001-4179.2009.23.019 JIANG Xiaomin, SONG Zhizhong. Anti-cavitation design of valve section gallery of high head ship lock[J]. Yangtze River, 2009, 40(23): 51-53. (in Chinese) doi: 10.3969/j.issn.1001-4179.2009.23.019 [4] 王新, 严秀俊.船闸平板输水阀门动力优化及流激振动特性分析[J].水运工程, 2013(12): 151-154. doi: 10.3969/j.issn.1002-4972.2013.12.029 WANG Xin, YAN Xiujun. Dynamic optimization and flow-induced vibration study on plate valve of ship lock[J]. Port & Waterway Engineering, 2013(12): 151-154. (in Chinese) doi: 10.3969/j.issn.1002-4972.2013.12.029 [5] 张陆陈, 骆少泽, 王新.陡槽高速泄流掺气减蚀试验研究[J].工程力学, 2013(增刊1): 328-332. http://www.cnki.com.cn/Article/CJFDTOTAL-GCLX2013S1067.htm ZHANG Luchen, LUO Shaoze, WANG Xin. Experimental study of air entrainment to alleviate cavitations for chute with high-speed discharge[J]. Engineering Mechanics, 2013(Suppl1): 328-332. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-GCLX2013S1067.htm [6] WANG Xin, LUO Shaoze, HU Ya'an, et al. High-speed flow erosion on a new roller compacted concrete dam during construction[J]. Journal of Hydrodynamics, 2012, 24(1): 32-38. doi: 10.1016/S1001-6058(11)60216-3 [7] WANG Xin, LUO Shaoze, LIU Guangsheng, et al. Abrasion test of flexible protective materials on hydraulic structures[J]. Water Science and Engineering, 2014, 7(1): 106-116. http://or.nsfc.gov.cn/bitstream/00001903-5/300058/1/1000014124077.pdf [8] WU Jianhua, GUO Wenjuan. Critical size effect of sand particles on cavitation damage[J]. Journal of Hydrodynamics, 2013, 25(1): 120-121. http://en.cnki.com.cn/Article_en/CJFDTOTAL-SDYW201301021.htm [9] XU Weilin, BAI Lixin, ZHANG Faxing. Interaction of a cavitation bubble and an air bubble with a rigid boundary[J]. Journal of Hydrodynamics, 2010, 22(4): 503-512. doi: 10.1016/S1001-6058(09)60082-2 [10] WU Jianhua, LUO Chao. Effects of entrained air manner on cavitation damage[J]. Journal of Hydrodynamics, 2011, 23(3): 333-338. doi: 10.1016/S1001-6058(10)60120-5 [11] HORSZCZARUK E. Abrasion resistance of high-strength concrete in hydraulic structures[J]. Wear, 2005, 259: 62-69. doi: 10.1016/j.wear.2005.02.079 [12] LUO Jing, XU Weilin, NIU Zhipan, et al. Experimental study of the interaction between the spark-induced cavitation bubble and the air bubble[J]. Journal of Hydrodynamics, 2013, 25(6): 895-902. doi: 10.1016/S1001-6058(13)60438-2 -
点击查看大图
计量
- 文章访问数: 1064
- HTML全文浏览量: 55
- PDF下载量: 453
- 被引次数: 0
