Since 1983 it has been reported many times that the tensile strength of a liquid has a noticeable influence on incipient cavitation test[1,2,3].In this paper some results indicate the characters of tensile strength of...Since 1983 it has been reported many times that the tensile strength of a liquid has a noticeable influence on incipient cavitation test[1,2,3].In this paper some results indicate the characters of tensile strength of test wa- ter in different cavitation test facilities for example;characters in normal cavitation tunnel without free surface and in depression tank with free surface respectively.For getting a comparable and stable test result of cavitation inception it is important to know the tensile strength of test water and to keep it stable.展开更多
The design method of small-flow high-head centrifugal-vortex pump was presented. This pump, configured with inducer, complex-centrifugal impeller and open-vortex impeller, was put forward to deliver gas-liquid two-pha...The design method of small-flow high-head centrifugal-vortex pump was presented. This pump, configured with inducer, complex-centrifugal impeller and open-vortex impeller, was put forward to deliver gas-liquid two-phase mixture. An HTB-5/60 type sample pump was developed and tested on a closed-loop test rig. Experimental studies on performance and cavitation tests for gas-liquid two-phase mixture were carried out compared with pure-water experimental results. Also the effect of gas phase on pump was analyzed and discussed. The experimental results show that performance and cavitation characteristics of the sample purnp deteriorates progressively with increasing volume fraction of gas. When the total capacity Qm is between 4.5 m^3·h^-1 and 6 m^3·h^-1 and the gas flow rate qg below 0.66 m^3·h^-1, or qg/Qm is lower than 15%, the characteristic curves are approximately parallel to those in pure water test, but the performance deteriorates sharply until an abrupt flow-cutting at a critical volume fraction of gas. This pump is found suitable for transporting gas-liquid two-phase mixture when working around rated capacity of 5 m^3·h^-1 with qglQm below 15%.展开更多
After about 10 years' runing of the LCC (DTRC, USA) and the HYKAT( HSVA,Germany) , another new large cavitation channel with low background noise is to be in operation inChina Ship Scientific Research Center(CSS-R...After about 10 years' runing of the LCC (DTRC, USA) and the HYKAT( HSVA,Germany) , another new large cavitation channel with low background noise is to be in operation inChina Ship Scientific Research Center(CSS-RC), Wuxi, China. The important specific properties of thechannel are the large test section (2. 0 m in height, 2. 2 m in width and 10. 5 m in length) , themaximum speed of more than 15 m/s, the low turbulence level, the low background noise of the wholefacility, together with the new noise measurement system. So large scale models can be tested withonly minor wall effects and at high Renolds numbers, and the pretentious acoustical measurements canbe performed. This paper describes the features of the new channel and the first test resultsobtained during extensive calibration and validation.展开更多
基金This work was supported by Chinese National Natural Science Foundation by the Hydraulic and Hydroelectric Engineering Foundation of China.
文摘Since 1983 it has been reported many times that the tensile strength of a liquid has a noticeable influence on incipient cavitation test[1,2,3].In this paper some results indicate the characters of tensile strength of test wa- ter in different cavitation test facilities for example;characters in normal cavitation tunnel without free surface and in depression tank with free surface respectively.For getting a comparable and stable test result of cavitation inception it is important to know the tensile strength of test water and to keep it stable.
基金Supported by the National Natural Science Foundation of China （50576088, 20706049） and Zhejiang Provincial Key Science Foundation （2006C21064, 2007C21067）.
文摘The design method of small-flow high-head centrifugal-vortex pump was presented. This pump, configured with inducer, complex-centrifugal impeller and open-vortex impeller, was put forward to deliver gas-liquid two-phase mixture. An HTB-5/60 type sample pump was developed and tested on a closed-loop test rig. Experimental studies on performance and cavitation tests for gas-liquid two-phase mixture were carried out compared with pure-water experimental results. Also the effect of gas phase on pump was analyzed and discussed. The experimental results show that performance and cavitation characteristics of the sample purnp deteriorates progressively with increasing volume fraction of gas. When the total capacity Qm is between 4.5 m^3·h^-1 and 6 m^3·h^-1 and the gas flow rate qg below 0.66 m^3·h^-1, or qg/Qm is lower than 15%, the characteristic curves are approximately parallel to those in pure water test, but the performance deteriorates sharply until an abrupt flow-cutting at a critical volume fraction of gas. This pump is found suitable for transporting gas-liquid two-phase mixture when working around rated capacity of 5 m^3·h^-1 with qglQm below 15%.
文摘After about 10 years' runing of the LCC (DTRC, USA) and the HYKAT( HSVA,Germany) , another new large cavitation channel with low background noise is to be in operation inChina Ship Scientific Research Center(CSS-RC), Wuxi, China. The important specific properties of thechannel are the large test section (2. 0 m in height, 2. 2 m in width and 10. 5 m in length) , themaximum speed of more than 15 m/s, the low turbulence level, the low background noise of the wholefacility, together with the new noise measurement system. So large scale models can be tested withonly minor wall effects and at high Renolds numbers, and the pretentious acoustical measurements canbe performed. This paper describes the features of the new channel and the first test resultsobtained during extensive calibration and validation.
