Identification Method of Current Conditions Suitable for Synchronous Machines Having Multiple Operating Points

2021 ◽  
Vol 141 (2) ◽  
pp. 173-184
Author(s):  
Katsutoku Takeuchi ◽  
Makoto Matsushita ◽  
Yuichi Tsuboi ◽  
Naoyuki Amemiya
Keyword(s):  
Synchronous Machines ◽  
Identification Method ◽  
Operating Points ◽  
Multiple Operating Points

scholarly journals Phase Distribution in the Tip Clearance of a Multiphase Pump at Multiple Operating Points and Its Effect on the Pressure Fluctuation Intensity

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 556
Author(s):  
Guangtai Shi ◽  
Zongku Liu ◽  
Xiaobing Liu ◽  
Yexiang Xiao ◽  
Xuelin Tang
Keyword(s):  
Phase Velocity ◽  
Pressure Fluctuation ◽  
Phase Distribution ◽  
Tip Clearance ◽  
Tip Leakage Flow ◽  
Two Phase ◽  
Multiphase Pump ◽  
Fluctuation Intensity ◽  
Operating Points ◽  
Multiple Operating Points

Tip clearance has a great effect on the flow and pressure fluctuation characteristics in a multiphase pump, especially at multiple operating points. The phase distribution and pressure fluctuation in tip clearance in a multiphase pump are revealed using the CFD (computational fluid dynamics) technology and high-speed photography methods. In this paper, the phase distribution, the gas-liquid two-phase velocity slip, and the pressure fluctuation intensity are comprehensively analyzed. Results show with the increase of the tip clearance, the multiphase pump pressurization performance is obviously deteriorated. In the meantime, the gas accumulation mainly occurs at the hub, the blade suction side (SS), and the tip clearance, and the maximum gas-liquid two-phase velocity difference is near the impeller streamwise of 0.4. In addition, the tip clearance improves the gas-liquid two-phase distribution in the pump, that is, the larger the tip clearance is, the more uniform the gas-liquid distribution becomes. Furthermore, the gas leads to the maximum pressure fluctuation intensity in the tip clearance which is closer to the tip leakage flow (TLF) outlet, and has a greater effect on the degree of flow separation in the tip clearance.

Multiple Operating Points in Complex Pump Networks

1979 ◽  
Vol 105 (3) ◽  
pp. 229-244
Author(s):  
Michael A. Collins ◽  
Jeff L. Kennington ◽  
Leon Cooper
Keyword(s):  
Operating Points ◽  
Multiple Operating Points

On Controllability and Observability of Linearized Liquid Water Distributions Inside a PEM Fuel Cell

2008 ◽  
Author(s):  
Buz A. McCain ◽  
Anna G. Stefanopoulou ◽  
Kenneth R. Butts
Keyword(s):  
Differential Equation ◽  
First Principles ◽  
Analytic Solution ◽  
Computational Cost ◽  
Pem Fuel Cell ◽  
Numeric Model ◽  
Analytic Models ◽  
Controllability And Observability ◽  
Operating Points ◽  
Multiple Operating Points

We analyze the controllability and observability (C/O) of first principles-based numeric and reduced semi-analytic PEMFC models, with emphasis on the effects of model reduction on these analyses. The numeric model is a partial differential equation (PDE) based model approximated by difference equations, including both channels and both GDL of a PEMFC. The reduced model uses a semi-analytic solution (SAS) method, which is a combination of analytic and numeric solutions, gaining physical intuition at lower computational cost. The C/O analysis is based on linearizations around multiple operating points of the numeric and the semi-analytic models. The results indicate that stabilizability of the anode water states is possible.

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