Dynamic analysis of the pump system based on MOC–CFD coupled method

2015 ◽  
Vol 78 ◽  
pp. 60-69 ◽  
Author(s):  
Shuai Yang ◽  
Xin Chen ◽  
Dazhuan Wu ◽  
Peng Yan
Author(s):  
Hua Lei ◽  
Huijün Hu ◽  
Yang Lu

A profiled chamber metering pump (PCMP) is a new type of positive-displacement vane pump which is composed of a special stator and a rotor–slide assembly. The face-shaped curve of the inner chamber of the stator is formed by means of two quarter circular arcs and two quarter noncircular arcs, and one of the two quarter noncircular arcs is defined as transition curve. The geometry of the transition curve directly affects the dynamic performances of the pump system, including its mechanical vibration, friction, wear, and kinetic losses. This paper discusses a set of dynamic analysis methods that combine kinetic loss control with vibration control for optimization of the transition curve of the PCMP. At first, basic conception and work line on the method are explained. In a second step, by means of force analysis, a kinetic loss model is established. Then, the model is used to examine a group of vibration optimized curves in polynomial form, and kinetic losses caused by different mechanical resistance forces are calculated. Finally, through a comparison analysis together with vibration and kinetic losses, comprehensive optimal transition curves can be obtained.


2013 ◽  
Vol 10 (01) ◽  
pp. 1340003 ◽  
Author(s):  
T. NGUYEN-THOI ◽  
P. PHUNG-VAN ◽  
T. RABCZUK ◽  
H. NGUYEN-XUAN ◽  
C. LE-VAN

An edge-based smoothed finite element method (ES-FEM-T3) using triangular elements was recently proposed to improve the accuracy and convergence rate of the existing standard finite element method (FEM) for the solid mechanics analyses. In this paper, the ES-FEM-T3 is further extended to the dynamic analysis of 2D fluid–solid interaction problems based on the pressure-displacement formulation. In the present coupled method, both solid and fluid domain is discretized by triangular elements. In the fluid domain, the standard FEM is used, while in the solid domain, we use the ES-FEM-T3 in which the gradient smoothing technique based on the smoothing domains associated with the edges of triangles is used to smooth the gradient of displacement. This gradient smoothing technique can provide proper softening effect, and thus improve significantly the solution of coupled system. Some numerical examples have been presented to illustrate the effectiveness of the proposed coupled method compared with some existing methods for 2D fluid–solid interaction problems.


Author(s):  
Fasuo Yan ◽  
Cheng Peng ◽  
Jun Zhang ◽  
Dagang Wang

Offshore turbines are gaining attention as means to capture the immense and relatively calm wind resources available over deep waters. A coupled dynamic analysis is required to evaluate the interactions between the wind turbine, floating hull and its mooring system. In this study, a coupled hydro-aero dynamic response analysis of a floating wind turbine system (NREL offshore-5MW baseline wind turbine) is carried out. A numerical code, known as COUPLE, has been extended to collaborate with FAST for the simulation of the dynamic interaction. Two methods were used in the analysis; one is coupled method and the other is limited coupled method. In the coupled method, the two codes are linked at each time step to solve the whole floating system. The limited coupled method assumes wind load is from a turbine installed on top of a fixed base, namely it doesn’t consider real-time configuration of floating carrier at each time step. Coupled technique is also mentioned to integrate the hydro-aero dynamic analysis in this paper. Six-degrees of freedom motion and mooring tensions are presented and compared. The numerical results derived in this study may provide crucial information for the design of a floating wind turbine in the future.


2021 ◽  
Author(s):  
Jeronimo de Moura Junior ◽  
Donald Rideout ◽  
Stephen Butt

2012 ◽  
Vol 220-223 ◽  
pp. 841-844
Author(s):  
Fa Suo Yan ◽  
Peng Fei Shen ◽  
Hong Wei Wang ◽  
Jun Zhang

A coupled dynamic analysis method is introduced for numerical simulation of floating wind turbine systems in this paper. A numerical code,which has been developed to perform couple hydrodynamic analysis of floating body together with its mooring system, is extended to collaborate with wind turbine simulator to evaluate the interactions between wind turbine and its floating base. To verify the coupled method, a dynamic response analysis of a spar type floating wind turbine system (NREL offshore-5MW baseline wind turbine) is carried out separately by the coupled Morison method and radiation-diffraction theory. Numerical results and comparison are presented. It turns out that this coupled method is competent enough to predict hydrodynamic performance of floating wind turbine system. The numerical results derived in this study may provide crucial information for the design of a floating wind turbine in the near future.


Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.


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