http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Pengzhou Li (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Zhang Yu,Li Pengzhou,Qiao Hongwei 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.11
The vibration of fuel rods in axial flow is a universally recognized issue within both engineering and academic communities due to its significant importance in ensuring structural safety. This paper aims to thoroughly investigate the stability and nonlinear vibration of a fuel rod subjected to axial flow in a newly designed high temperature gas cooled reactor. Considering the possible presence of thermal expansion and large deformation in practical scenarios, the thermal effect and geometric nonlinearity are modeled using the von Karman equation. By applying Hamilton’s principle, we derive the comprehensive governing equation for this fluid-structure interaction system, which incorporates the quadratic nonlinear stiffness. To establish a connection between the fluid and structure aspects, we utilize the Galerkin method to solve the perturbation potential function, while employing mode expansion techniques associated with the structural analysis. Following convergence and validation analyses, we examine the stability of the structure under various conditions in detail, and also investigate the bifurcation behavior concerning the buckling amplitude and flow velocity. The findings from this research enhance the understanding of the underlying physics governing fuel rod behavior in axial flow under severe yet practical conditions, while providing valuable guidance for reactor design.
-
Jiang Lai,Lei Sun,Pengzhou Li 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.6
Fluidelastic instability and nonlinear dynamics of tube bundles is a key issue in a steam generator. Especially, once the post-instability motion of the tube becomes larger than the clearance gap to othertubes, effective contact or impact between the tubes under consideration and the other tube inevitable. There is seldom theoretical analysis to the nonlinear dynamic characteristics of a tube array in two-phaseflow. In this paper, experimental and numerical studies were utilized to obtain the critical velocity of theflow-induced instability of a rotated triangular tube array. The calculation results agreed well with theexperimental data. To explore the post-instability dynamics of the tube array system, a Runge-Kuttascheme was used to solve the nonlinear governing equations of tube motion. The numerical resultsindicated that, when the flow pitch velocity is larger than the critical velocity, the tube array system isundergoing a limit cycle motion, and the dynamic characteristics of the tube array are almost similar fordifferent void fractions
-
Lai, Jiang,He, Chao,Sun, Lei,Li, Pengzhou Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.3
The reliability of the spent fuel pool instrument is very important for the security of nuclear power plant, especially during the earthquake. The effect of the fluid force on the vibration characteristics of the flexible tube of the spent fuel pool instrument needs comprehensive analysis. In this paper, based on the potential flow theory, the hydrodynamic pressures acting on the flexible tube were obtained. A mathematical model of a flexible tube was constructed to obtain the dynamic response considering the effects of seismic load and fluid force, and a computer code was written. Based on the mathematical model and computer code, the maximum stresses of the flexible tube in both safe shutdown earthquake and operating basis earthquake events on the spent fuel pool with three typical water levels were calculated, respectively. The results show that the fluid force has an obvious effect on the stress and strain of the flexible tube in both safe shutdown earthquake and operating basis earthquake events.
-
Huantong Liu,Jiang Lai,Lei Sun,Pengzhou Li,Lixia Gao,Danping Yu 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.8
Fluidelastic instability of a tube array is a key factor of the security of a nuclear power plant. An unsteady model of the fluidelastic instability of a tube array subjected to two-phase flow was developed to analyze the fluidelastic instability of tube bundles in two-phase flow. Based on this model, a computational program was written to calculate the eigenvalue and the critical velocity of the fluidelastic instability. The unsteady model and the program were verified by comparing with the experimental results reported previously. The influences of void fraction and the tube's material properties on the critical velocity were investigated. Numerical results showed that, with increasing the void fraction of the two-phase flow, the tube array becomes more stable. The results indicate that the critical velocities of the tube array made of stainless are much higher than those of the other two tube arrays within void fraction ranging from 20%to 80%.
-
Mechanism analysis on fluidelastic instability of tube bundles in considering of cross-flow effects
Jiang Lai,Lei Sun,Lixia Gao,Pengzhou Li 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.1
Fluidelastic instability is a key issue in steam generator tube bundles subjected in cross-flow. With a lowflow velocity, a large amplitude vibration of the tube observed by many researchers. However, themechanism of this vibration is seldom analyzed. In this paper, the mechanism of cross-flow effects onfluidelastic instability of tube bundles was investigated. Analysis reveals that when the system reachesthe critical state, there would be two forms, with two critical velocities, and thus two expressions for thecritical velocities were obtained. Fluidelastic instability experiment and numerical analysis were conductedto obtain the critical velocity. And, if system damping is small, with increases of the flow velocity,the stability behavior of tube array changes. At a certain flow velocity, the stability of tube array reachesthe first critical state, a dynamic bifurcation occurs. The tube array returns to a stable state with continuesto increase the flow velocity. At another certain flow velocity, the stability of tube array reachesthe second critical state, another dynamic bifurcation occurs. However, if system damping is big, there isonly one critical state with increases the flow velocity. Compared the results of experiments to numericalanalysis, it shows a good agreement.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
