To investigate the influence of bluff body shape on wall pressure distribution in a vortex flowmeter,experiments were conducted on a specially designed test section in a closed water rig at Reynolds numbers of 6.2...To investigate the influence of bluff body shape on wall pressure distribution in a vortex flowmeter,experiments were conducted on a specially designed test section in a closed water rig at Reynolds numbers of 6.2×10 4-9.3×10 4.The cross sections of the bluff bodies were semicircular,square,and triangular shaped,and there were totally 21 pressure tappings along the conduit to acquire the wall pressures.It is found that the variation trends of wall pressures are basically identical regardless of the bluff body shapes.The wall pressures begin to diverge from 0.3D(D is the inner diameter of the vortex flowmeter) in front of the bluff body due to the diversity in shape,and all reach the minimum values at 0.3D behind the bluff body.A discrepancy between the triangular or square cylinder and the semicircular cylinder in wall pressure change is observed at 0-0.1D behind the bluff body.It is also found that the wall pressures and irrecoverable pressure loss coefficients increase with flow rates,and the triangular cylinder causes the smallest irrecoverable pressure loss at a fixed flow rate.展开更多
Pascal Triangle is more of a number construction （body） then an array of the binomial coefficients. It is a mathematical body, like the digital code feeds for computer but with 2 dimensions. And there should be bodi...Pascal Triangle is more of a number construction （body） then an array of the binomial coefficients. It is a mathematical body, like the digital code feeds for computer but with 2 dimensions. And there should be bodies with x-dimensions and even abnormal or irregular appearances.展开更多
The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerieally. In our findings, when the system is with only repuls...The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerieally. In our findings, when the system is with only repulsive twobody interactions or only three-body interactions, the tunneling will be suppressed; while in the case of the coupling between two- and three-body interactions, the tunneling can be either suppressed or enhanced. Particularly, when attractive three-body interactions are twice large as repulsive two-body interactions, CDT occurs at isolated points of driving force, which is similar to the linear case. Considering different interaction, the system can experience different transformation from coherent tunneling to coherent destruction of tunneling （CDT）. The quasi-energy of the system as the function of the periodicaJ1y driving force shows a triangular structure, which provides a deep insight into the tunneling dynamics of the system.展开更多
基金Project(51006125) supported by the National Natural Science Foundation of China
文摘To investigate the influence of bluff body shape on wall pressure distribution in a vortex flowmeter,experiments were conducted on a specially designed test section in a closed water rig at Reynolds numbers of 6.2×10 4-9.3×10 4.The cross sections of the bluff bodies were semicircular,square,and triangular shaped,and there were totally 21 pressure tappings along the conduit to acquire the wall pressures.It is found that the variation trends of wall pressures are basically identical regardless of the bluff body shapes.The wall pressures begin to diverge from 0.3D(D is the inner diameter of the vortex flowmeter) in front of the bluff body due to the diversity in shape,and all reach the minimum values at 0.3D behind the bluff body.A discrepancy between the triangular or square cylinder and the semicircular cylinder in wall pressure change is observed at 0-0.1D behind the bluff body.It is also found that the wall pressures and irrecoverable pressure loss coefficients increase with flow rates,and the triangular cylinder causes the smallest irrecoverable pressure loss at a fixed flow rate.
文摘Pascal Triangle is more of a number construction （body） then an array of the binomial coefficients. It is a mathematical body, like the digital code feeds for computer but with 2 dimensions. And there should be bodies with x-dimensions and even abnormal or irregular appearances.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11274255 and 11305132Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.20136203110001+1 种基金the Natural Science Foundation of Gansu Province under Grant No.2011GS04358Creation of Science and Technology of Northwest Normal University under Grant Nos.NWNUKJCXGC-03-48,NWNU-LKQN-12-12
文摘The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerieally. In our findings, when the system is with only repulsive twobody interactions or only three-body interactions, the tunneling will be suppressed; while in the case of the coupling between two- and three-body interactions, the tunneling can be either suppressed or enhanced. Particularly, when attractive three-body interactions are twice large as repulsive two-body interactions, CDT occurs at isolated points of driving force, which is similar to the linear case. Considering different interaction, the system can experience different transformation from coherent tunneling to coherent destruction of tunneling （CDT）. The quasi-energy of the system as the function of the periodicaJ1y driving force shows a triangular structure, which provides a deep insight into the tunneling dynamics of the system.
