During the hydrodynamic characteristic testing of aortic valve allograft (AVA),the testing condition was adjusted to obtain the best hydraulic performance of AVA.The testing condition,the character of the circulation ...During the hydrodynamic characteristic testing of aortic valve allograft (AVA),the testing condition was adjusted to obtain the best hydraulic performance of AVA.The testing condition,the character of the circulation duplicator,is regarded as to beconsistent with the human circulation in vivo.Then the comparison among the re-sults of AVA orifice area (AVA) estimated by Gorlin formula,the continuity equa-tion and their modified types,respectively,was performed.展开更多
Multi stage and multi orifice throttling analysis for bypass valves in thermal power generating sets is important for normal operation of power generating equipment. It is improper to exclude the factor of flow resist...Multi stage and multi orifice throttling analysis for bypass valves in thermal power generating sets is important for normal operation of power generating equipment. It is improper to exclude the factor of flow resistance from the expansion coefficient for the flow formula used for analysing the multi stage and multi orifice flow of compressible fluid, which means expansion of gas has nothing to do with resistance. The authors put forward an expanded energy equation and related formula to overcome the drawback, and use them for multi stage and multi orifice throttling analysis of compressible fluid for thermal power generating sets.展开更多
This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at ...This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at the downstream end of the penstock. Analytical formulas of maximum water hammer pressures at the downstream end of the tunnel and the valve were derived for a system subjected to linear and slow valve closure. The analytical results were then compared with numerical ones obtained using the method of characteristics. There is agreement between them. The formulas can be applied to estimating water hammer pressure at the valve and transmission of water hammer pressure through the surge chamber at the junction for a hydraulic pipe system with a surge chamber.展开更多
文摘During the hydrodynamic characteristic testing of aortic valve allograft (AVA),the testing condition was adjusted to obtain the best hydraulic performance of AVA.The testing condition,the character of the circulation duplicator,is regarded as to beconsistent with the human circulation in vivo.Then the comparison among the re-sults of AVA orifice area (AVA) estimated by Gorlin formula,the continuity equa-tion and their modified types,respectively,was performed.
文摘Multi stage and multi orifice throttling analysis for bypass valves in thermal power generating sets is important for normal operation of power generating equipment. It is improper to exclude the factor of flow resistance from the expansion coefficient for the flow formula used for analysing the multi stage and multi orifice flow of compressible fluid, which means expansion of gas has nothing to do with resistance. The authors put forward an expanded energy equation and related formula to overcome the drawback, and use them for multi stage and multi orifice throttling analysis of compressible fluid for thermal power generating sets.
基金supported by the National Natural Science Foundation of China (Grant No.50539070)the Major State Basic Research Development Program of China (Grant No.2006CB403304)
文摘This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at the downstream end of the penstock. Analytical formulas of maximum water hammer pressures at the downstream end of the tunnel and the valve were derived for a system subjected to linear and slow valve closure. The analytical results were then compared with numerical ones obtained using the method of characteristics. There is agreement between them. The formulas can be applied to estimating water hammer pressure at the valve and transmission of water hammer pressure through the surge chamber at the junction for a hydraulic pipe system with a surge chamber.
