A new instrument for upper ocean survey, namely the UCTD （Underway Conductivity-Temperature- Depth）, which combines some of the advantages of other underway instruments, is introduced in this paper. The Introduction...A new instrument for upper ocean survey, namely the UCTD （Underway Conductivity-Temperature- Depth）, which combines some of the advantages of other underway instruments, is introduced in this paper. The Introduction section presents a description of the construction and function of the UCTD, and the experiments conducted in the South China Sea on board the R/V Dong Fang Hong 2 in July 2007 and August 2008. The UCTD system, with pressure and temperature sensors in the probe, is con- veniently portable, cost-effective and environment-friendly. It is hopefully suitable for future cruises. An intercomparison based on regressing with the experiment temperature data from both SeaBird plus911 CTD and the UCTD showed that the standard deviation is 0.88~C and the correlation coefficient is 0.96, achieving the goals set for the current oceanography uses. In the hydrodynamic experiments, the descending velocities and depths were calculated for different ship speeds. A pulling test was designed with a tensiorneter to measure the magnitude of the pull. The maximal tension of the line was found to be 66.2 kg, which is far lower than the bearing limit of the Hollow Spectra line. Finally, some improvement suggestions are put forward for future experiments and production.展开更多
In this research, centrifugal pump unit was analysed to study the effects of using inducers on its performance. Hydraulic tests were done to obtain the optimum hydraulic performance before and after using inducer. Two...In this research, centrifugal pump unit was analysed to study the effects of using inducers on its performance. Hydraulic tests were done to obtain the optimum hydraulic performance before and after using inducer. Two types of inducers were used in this work （axial, helical）. For this purpose, a test rig was specially designed with a pump system to investigate the parameters under consideration. Plots （H-Q） curves, （B.P.-Q） curves and （q-Q） curves were used to show the effect of pump performance with and without inducers. The present study introduces a simulation of centrifugal pump performance in conjunction with inducers using CFD （Computational Fluid Dynamics）, to compare it with experimentally observed values. The model investigates the impact of using inducers on the head and flow of the pump. The results of the CFD model and experimental are correlated well. Furthermore, the results help the decision makers of the pumps for future developments in pump performance assuring safe and reliable running condition of the water pumps. Also it may be used for more applications of larger head and flow pumps.展开更多
基金support of the National High Technology Research and Development Program of China (Nos.2006AA09A314 and 2006AA09A307)the National Natural Science Fund (40706006)+2 种基金China’s Na-tional Basic Research Priorities Programmer (2005CB- 422303 and 2007CB411804)the key project of the In-ternational Science and Technology Cooperation Program of China (2006DFB21250)the Ministry of Educa-tion’s 111 Project (B07036)
文摘A new instrument for upper ocean survey, namely the UCTD （Underway Conductivity-Temperature- Depth）, which combines some of the advantages of other underway instruments, is introduced in this paper. The Introduction section presents a description of the construction and function of the UCTD, and the experiments conducted in the South China Sea on board the R/V Dong Fang Hong 2 in July 2007 and August 2008. The UCTD system, with pressure and temperature sensors in the probe, is con- veniently portable, cost-effective and environment-friendly. It is hopefully suitable for future cruises. An intercomparison based on regressing with the experiment temperature data from both SeaBird plus911 CTD and the UCTD showed that the standard deviation is 0.88~C and the correlation coefficient is 0.96, achieving the goals set for the current oceanography uses. In the hydrodynamic experiments, the descending velocities and depths were calculated for different ship speeds. A pulling test was designed with a tensiorneter to measure the magnitude of the pull. The maximal tension of the line was found to be 66.2 kg, which is far lower than the bearing limit of the Hollow Spectra line. Finally, some improvement suggestions are put forward for future experiments and production.
文摘In this research, centrifugal pump unit was analysed to study the effects of using inducers on its performance. Hydraulic tests were done to obtain the optimum hydraulic performance before and after using inducer. Two types of inducers were used in this work （axial, helical）. For this purpose, a test rig was specially designed with a pump system to investigate the parameters under consideration. Plots （H-Q） curves, （B.P.-Q） curves and （q-Q） curves were used to show the effect of pump performance with and without inducers. The present study introduces a simulation of centrifugal pump performance in conjunction with inducers using CFD （Computational Fluid Dynamics）, to compare it with experimentally observed values. The model investigates the impact of using inducers on the head and flow of the pump. The results of the CFD model and experimental are correlated well. Furthermore, the results help the decision makers of the pumps for future developments in pump performance assuring safe and reliable running condition of the water pumps. Also it may be used for more applications of larger head and flow pumps.
