For the metal spiral casing of water turbines, a new equivalent pipe algorithm is developed based on the idea of equiangu-lar spiral. Prototype tests and computations are carried out to investigate the hydraulic trans...For the metal spiral casing of water turbines, a new equivalent pipe algorithm is developed based on the idea of equiangu-lar spiral. Prototype tests and computations are carried out to investigate the hydraulic transient characteristics. The computation re-sults by using the new model are in a good agreement with the prototype test data with respect to the maximum speed of the tur-bine-generator unit, the maximum water hammer pressure in the spiral casing and the maximum vacuum in the draft tube. The propo-sed method is a significant improvement over the conventional algorithm with the accuracy increased and the error reduced by about 3%.展开更多
In this paper,the common-mode radiation characteristic of the connection between a cable and a conductor is analyzed by the electric field integral function(EFIF)and the method of moment(MoM).The RWG basis function is...In this paper,the common-mode radiation characteristic of the connection between a cable and a conductor is analyzed by the electric field integral function(EFIF)and the method of moment(MoM).The RWG basis function is adopted as the conductor basis function,the pulse basis function as the wire basis function and the juncture employs Costa basis function.A scheme of singular region separation is proposed to overcome the integration singularity of juncture matrix elements.Some new conclusions of the common-mode radiation characteristics with the metal case are obtained by numeration.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.51179114)
文摘For the metal spiral casing of water turbines, a new equivalent pipe algorithm is developed based on the idea of equiangu-lar spiral. Prototype tests and computations are carried out to investigate the hydraulic transient characteristics. The computation re-sults by using the new model are in a good agreement with the prototype test data with respect to the maximum speed of the tur-bine-generator unit, the maximum water hammer pressure in the spiral casing and the maximum vacuum in the draft tube. The propo-sed method is a significant improvement over the conventional algorithm with the accuracy increased and the error reduced by about 3%.
文摘In this paper,the common-mode radiation characteristic of the connection between a cable and a conductor is analyzed by the electric field integral function(EFIF)and the method of moment(MoM).The RWG basis function is adopted as the conductor basis function,the pulse basis function as the wire basis function and the juncture employs Costa basis function.A scheme of singular region separation is proposed to overcome the integration singularity of juncture matrix elements.Some new conclusions of the common-mode radiation characteristics with the metal case are obtained by numeration.
