scholarly journals Analytical model of hybrid MMC for dynamic and steady-state studies

2017 ◽  
Vol 2017 (13) ◽  
pp. 2281-2286
Author(s):  
Xiaojun Lu ◽  
Wang Xiang ◽  
Weixing Lin ◽  
Jinyu Wen
Keyword(s):  
Steady State ◽  
Analytical Model

Rubbing Phenomena in Rotor-Stator Contact

2000 ◽  
Author(s):  
Z. C. Feng ◽  
Xiao-Zhang Zhang
Keyword(s):  
Steady State ◽  
Radial Velocity ◽  
Analytical Model ◽  
Contact Surface ◽  
Initial Perturbation ◽  
Instantaneous Change

Abstract This paper discusses the vibration phenomena of a rotor rubbing with a stator caused by an initial perturbation. The analytical model consists of a simple disc-shaft rotor and a fixed stator. The perturbation is an instantaneous change of the radial velocity when the rotor is rotating in its normal steady state. It is found that under certain conditions, the rotor will remain rubbing with the stator, even if the initial perturbation no longer exists. In the case of no friction on the contact surface between the rotor and the stator, the full rubbing behaves as forward whirling. When friction is present, the full rubbing behaves as backward whirling.

Simulation of the Steady-State Photocarrier Grating Method Applied to Amorphous Materials

1992 ◽  
Vol 258 ◽  
Author(s):  
C.-D. Abel ◽  
G. H. Bauer
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Electric Field ◽  
Closed Form ◽  
Analytical Model ◽  
Amorphous Materials ◽  
Grating Period ◽  
Amorphous Semiconductors ◽  
Closed Form Expression ◽  
Form Expression

ABSTRACTGeneral features of the steady-state photocarrier grating technique applied to amorphous semiconductors are investigated by complete numerical simulation. The results are interpreted with an analytical model which delivers a closed-form expression for β(A,E) assuming dominance of one carrier type. The variation of the electric field E instead of the grating period A is suggested as an easier and more accurate tool for the experimental technique.

scholarly journals A 2.5-D electron Hall-MHD analytical model of steady state Hall magnetic reconnection in a compressible plasma

2011 ◽  
Vol 116 (A5) ◽  
Author(s):  
D. B. Korovinskiy ◽  
V. S. Semenov ◽  
N. V. Erkaev ◽  
A. V. Divin ◽  
H. K. Biernat ◽  
...  
Keyword(s):  
Steady State ◽  
Magnetic Reconnection ◽  
Analytical Model ◽  
Compressible Plasma ◽  
Hall Mhd

Two-dimensional steady-state thermal analytical model of permanent-magnet synchronous machines operating in generator mode

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zakarya Djelloul Khedda ◽  
Kamel Boughrara ◽  
Frédéric Dubas ◽  
Baocheng Guo ◽  
El Hadj Ailam
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Permanent Magnet ◽  
Analytical Model ◽  
Electrical Machines ◽  
Synchronous Machines ◽  
Analytical Prediction ◽  
Two Dimensional ◽  
Content Type ◽  
Proposed Model

Purpose Thermal analysis of electrical machines is usually performed by using numerical methods or lumped parameter thermal networks depending on the desired accuracy. The analytical prediction of temperature distribution based on the formal resolution of thermal partial differential equations (PDEs) by the harmonic modeling technique (or the Fourier method) is uncommon in electrical machines. Therefore, this paper aims to present a two-dimensional (2D) analytical model of steady-state temperature distribution for permanent-magnet (PM) synchronous machines (PMSM) operating in generator mode. Design/methodology/approach The proposed model is based on the multi-layer models with the convolution theorem (i.e. Cauchy’s product theorem) by using complex Fourier’s series and the separation of variables method. This technique takes into the different thermal conductivities of the machine parts. The heat sources are determined by calculating the different power losses in the PMSM with the finite-element method (FEM). Findings To validate the proposed analytical model, the analytical results are compared with those obtained by thermal FEM. The comparisons show good results of the proposed model. Originality/value A new 2D analytical model based on the PDE in steady-state for full prediction of temperature distribution in the PMSM takes into account the heat transfer by conduction, convection and radiation.

An analytical model for simulating steady state flows of downburst

2013 ◽  
Vol 115 ◽  
pp. 53-64 ◽  
Author(s):  
El-Sayed Abd-Elaal ◽  
Julie E. Mills ◽  
Xing Ma
Keyword(s):  
Steady State ◽  
Analytical Model

Novel, Gasketless, Interconnect Using Parallel Superhydrophobic Surfaces for Modular Microfluidic Systems

2011 ◽  
Author(s):  
Christopher R. Brown ◽  
Bahador Farshchian ◽  
Pin-Chuan Chen ◽  
Taehyun Park ◽  
Sunggook Park ◽  
...  
Keyword(s):  
Steady State ◽  
Analytical Model ◽  
Liquid Bridge ◽  
Contact Angles ◽  
Superhydrophobic Surfaces ◽  
Maximum Pressure ◽  
The Novel ◽  
Microfluidic Systems ◽  
Order Of Magnitude ◽  
State Pressure

A novel, modular, microfluidic interconnect was developed using parallel superhydrophobic interfaces to facilitate the transport of fluids between component chips in modular microfluidic systems. A static analytical model, derived from the Laplace equation [1], approximates the maximum steady-state pressure of the liquid at the liquid bridge which forms across the gap between the chips. Preliminary experiments using parallel superhydrophobic surfaces on PMMA validated the concept. Additional experiments controlled the gap distance, measured contact angles of the superhydrophobic surfaces, gradually increased the pressure of the novel, gasketless, interconnect until rupture to find the maximum pressure across the liquid bridge and verify the model. The measured pressures were on the same order of magnitude (1–10 kPa) as estimated using the model for gap distances of 25 μm and 100 μm.

Mathematical Modeling of a Miniature Loop Heat Pipe With Two Evaporators and Two Condensers

2009 ◽  
Author(s):  
Jentung Ku ◽  
Triem Hoang ◽  
Tamara O’Connell
Keyword(s):  
Steady State ◽  
Heat Pipe ◽  
Analytical Model ◽  
Computer Code ◽  
Loop Heat Pipe ◽  
Performance Tests ◽  
Thermal Vacuum ◽  
Start Up ◽  
Gravity Effects ◽  
Transient Thermal

A loop heat pipe (LHP) analytical model that simulates the steady state and transient thermal behaviors of LHPs with multiple evaporators and multiple condensers has recently been developed. It can be used as a stand-alone computer code or as a subroutine to general spacecraft thermal analyzers. Multi-evaporator and multi-condenser LHPs are more complex in their operation when compared to single-evaporator LHPs because of the thermal and fluid interactions among the evaporators, compensation chambers, and condensers. This analytical model has been used to simulate the thermal performance of a miniature loop heat pipe (MLHP) with two evaporators and two condensers in laboratory and thermal vacuum tests. In addition, the MLHP was tested in the laboratory under five different configurations where the relative elevations and tilts among loop components were varied so as to investigate the gravity effects on the loop performance and to verify the analytical model’s capability to predict such effects. The MLHP performance tests that were simulated included start-up, high power, heat transport limit, and heat load sharing between the two evaporators. In all tests that were modeled, the LHP analytical model accurately predicted the steady state and transient behaviors of the LHP. Furthermore, the model was run-time efficient and yielded stable solutions in all cases.

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