Coupling phenomenon of anti-connected hybrid alignment nematics in thin cell: From submicron to nanoscale

2019 ◽  
Vol 33 (04) ◽  
pp. 1950002 ◽  
Author(s):  
Sibo Chen ◽  
Xiaoting Liu ◽  
Huimin Yu ◽  
Xuan Zhou ◽  
Zhidong Zhang
Keyword(s):  
Numerical Simulation ◽  
Coherence Length ◽  
Structure Transition ◽  
Maximum Value ◽  
Order Reconstruction ◽  
Novel Approach ◽  
New Type ◽  
Degenerate States ◽  
Simulation Results ◽  
Gennes Theory

Within Landau–de Gennes theory, we modeled a system consisting of two anti-connected hybrid alignment nematics (HAN). Our numerical simulation results indicated the occurrence of four states denoted as I, II, III and IV. The states undergo a structure transition as a function of the cell gap d. For d [Formula: see text] d0, where d0 is the maximum value for the structure transition to occur, state I and II are bistable, whereas state III and IV are metastable and quadruply degenerate. We found that d0 = 15[Formula: see text], where [Formula: see text] is the biaxial characteristic coherence length. When d[Formula: see text] [Formula: see text] d [Formula: see text] d0, where d[Formula: see text] = 7[Formula: see text] and d[Formula: see text] is the critical cell gap for order reconstruction (OR), continuous inversion walls appear both in state III and IV. We first found that the structure transition from inversion walls to defect walls occurs with decreasing d from the submicron to nanoscale. During this process, quadruply degenerate states in state III and IV transformed into doubly degenerate states. Meanwhile, states I and II remained bistable. When d = d[Formula: see text], all states reached a new type of OR pattern with two biaxial walls cross-linked with each other by a novel approach; i.e., from defect walls to OR.

Design and Simulation Research on Mechanical Ventilation System for Small Underground Granary

2014 ◽  
Vol 875-877 ◽  
pp. 2148-2151
Author(s):  
Hai Hong Zhang ◽  
Zhong Ying Wang ◽  
Qiang Liu ◽  
Peng Fei Ma
Keyword(s):  
Numerical Simulation ◽  
Mechanical Ventilation ◽  
Pressure Field ◽  
Ventilation System ◽  
Simulation Research ◽  
New Type ◽  
Simulation Results ◽  
Dynamic Numerical Simulation ◽  
Set Up ◽  
Better Than

The mechanical ventilation system of new type underground granary was designed and three wind pipe models with different length were investigated in this paper. Dynamic numerical simulation was applied for evaluating the cooling effect of mechanical ventilation of the granary. The simulation results, including temperature field, flow field and pressure field results, show that the cone shaped base of grain granary is better than flat shaped base. It is an optimal project that the main wind pipe opens with mesh only in the bottom. In addition, four vertical guide plates were set up around the main wind pipe, which have the function of saving energy and reducing consumption.

Simulation Research of Interior Ballistics Performance for a New-Type Light Caliber Cannon

2013 ◽  
Vol 446-447 ◽  
pp. 458-462
Author(s):  
Jia Ning Li ◽  
Xin Liao ◽  
Feng Qiang Nan
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Phase Flow ◽  
Gas Temperature ◽  
Projectile Velocity ◽  
Two Phase ◽  
Simulation Research ◽  
Interior Ballistics ◽  
New Type ◽  
Simulation Results

In order to make a precise interpret and research of interior ballistics performance for a new-type light caliber cannon, an interior ballistics mathematical and physical model was established, on the basis of two-phase flow interior ballistics theory and description of interior ballistic cycle. MATLAB software was used to conduct numerical simulation. Conclusion indicates that the simulation results manifest favorable consistency with the experiment results. Simulation results can comprehensively interpret the physical process in guns by pressure distribution, projectile velocity and gas temperature distribution.

The Finite Element Analysis of a New Type Reinforcement Form of Light Steel Ceiling

2014 ◽  
Vol 1065-1069 ◽  
pp. 1277-1280
Author(s):  
Zhuang Nan Zhang ◽  
Zhen Dong Tan ◽  
Guo Chang Li
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Methods ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
New Type ◽  
Simulation Results

This paper puts a form of reinforcement with used finite element methods to carry on the numerical simulation of a new type reinforcement form of light steel ceiling. Compared with the ordinary ceiling, the new reinforcement form of light steel ceiling can greatly improve the capacity of the ceiling sideways resistance with the overall strong stiffness from the simulation results.

Modeling and Simulation of Thermostatic Mixing Valve

2013 ◽  
Vol 365-366 ◽  
pp. 370-374
Author(s):  
Hai Chu Chen ◽  
Fang Yi Wu ◽  
Ping Zhang ◽  
Gen Liang Xiong ◽  
Yin Fa Zhu
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Flow Field ◽  
Modeling And Simulation ◽  
Adaptive Controller ◽  
Theoretical Research ◽  
New Type ◽  
Fluent Software ◽  
Simulation Results ◽  
The Mathematical Model

It researched a new type of intelligent thermostatic mixing valve which could keep the temperature and flux of the valve outlet water constant through the adaptive controller. It firstly established the mathematical model about angle - flux and angle - temperature of the valve. And then it based on thekεturbulence model and applied Fluent software to numerical simulation of the valve about the flow field. Finally, it compared the simulation results with the calculated value. The results show that they are basically consistent, prove the correctness of the theoretical research, and can be used to improve designing of the thermostatic valve.

Research on Hydrodynamic Performance of Front-Mounted Water Separation Propeller

2012 ◽  
Vol 166-169 ◽  
pp. 2976-2981
Author(s):  
Feng Feng ◽  
Xin Chang ◽  
Xiang Ru Cheng ◽  
Xiang Yang Qi
Keyword(s):  
Numerical Simulation ◽  
Hydrodynamic Performance ◽  
Test Results ◽  
Water Separation ◽  
Ship Model ◽  
Vof Model ◽  
Sst Turbulence Model ◽  
New Type ◽  
Simulation Results ◽  
Hybrid Grid

The Front-mounted Water Separation Propeller is a new-type energy saving propulsion device, on which it’s necessary to make research. A numerical simulation on the hydrodynamic performance of the Front-mounted Water Separation Propeller by RANS method was performed. The simple ship models with and without Front-mounted Water Separation Propeller were established and meshed by using hybrid grid. The drag performances of the ship model with and without Front-mounted Water Separation Propeller were performed separately by using Kω-SST turbulence model and VOF model. The method provided in this article is proved to be effective by make comparison between the simulation results and the model test results. The results show that the ship resistance can be reduced by using the Front-mounted Water Separation Propeller.

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

An Intuitionistic Fuzzy Based Novel Approach to CPU Scheduler

2020 ◽  
Vol 16 (4) ◽  
pp. 316-328
Author(s):  
Supriya Raheja
Keyword(s):  
Fuzzy Inference ◽  
The Other ◽  
Simulation Environment ◽  
Inference System ◽  
Intuitionistic Fuzzy ◽  
Novel Approach ◽  
Continuous Feedback ◽  
Simulation Results ◽  
Effectiveness And Efficiency ◽  
Unique Capability

Background: The extension of CPU schedulers with fuzzy has been ascertained better because of its unique capability of handling imprecise information. Though, other generalized forms of fuzzy can be used which can further extend the performance of the scheduler. Objectives: This paper introduces a novel approach to design an intuitionistic fuzzy inference system for CPU scheduler. Methods: The proposed inference system is implemented with a priority scheduler. The proposed scheduler has the ability to dynamically handle the impreciseness of both priority and estimated execution time. It also makes the system adaptive based on the continuous feedback. The proposed scheduler is also capable enough to schedule the tasks according to dynamically generated priority. To demonstrate the performance of proposed scheduler, a simulation environment has been implemented and the performance of proposed scheduler is compared with the other three baseline schedulers (conventional priority scheduler, fuzzy based priority scheduler and vague based priority scheduler). Results: Proposed scheduler is also compared with the shortest job first CPU scheduler as it is known to be an optimized solution for the schedulers. Conclusion: Simulation results prove the effectiveness and efficiency of intuitionistic fuzzy based priority scheduler. Moreover, it provides optimised results as its results are comparable to the results of shortest job first.

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

scholarly journals Numerical and Experimental Study of Lightning Stroke to BIPV Modules

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 748
Author(s):  
Xiaoyan Bian ◽  
Yao Zhang ◽  
Qibin Zhou ◽  
Ting Cao ◽  
Bengang Wei
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Coupling Model ◽  
Maximum Temperature ◽  
Lightning Stroke ◽  
Study Results ◽  
Pv Modules ◽  
New Type ◽  
Metal Frame ◽  
Current Flows

Building Integrated Photovoltaic (BIPV) modules are a new type of photovoltaic (PV) modules that are widely used in distributed PV stations on the roof of buildings for power generation. Due to the high installation location, BIPV modules suffer from lightning hazard greatly. In order to evaluate the risk of lightning stroke and consequent damage to BIPV modules, the studies on the lightning attachment characteristics and the lightning energy withstand capability are conducted, respectively, based on numerical and experimental methods in this paper. In the study of lightning attachment characteristics, the numerical simulation results show that it is easier for the charges to concentrate on the upper edge of the BIPV metal frame. Therefore, the electric field strength at the upper edge is enhanced to emit upward leaders and attract the lightning downward leaders. The conclusion is verified through the long-gap discharge experiment in a high voltage lab. From the experimental study of multi-discharge in the lab, it is found that the lightning interception efficiency of the BIPV module is improved by 114% compared with the traditional PV modules. In the study of lightning energy withstand capability, a thermoelectric coupling model is established. With this model, the potential, current and temperature can be calculated in the multi-physical field numerical simulation. The results show that the maximum temperature of the metal frame increases by 16.07 °C when 100 kA lightning current flows through it and does not bring any damage to the PV modules. The numerical results have a good consistency with the experimental study results obtained from the 100 kA impulse current experiment in the lab.

Sublimation of composite ice and its influence on performance of ice shells

2021 ◽  
Vol 36 (1) ◽  
pp. 67-77
Author(s):  
Yue Wu ◽  
Junkai Huang ◽  
Jiafeng Chen
Keyword(s):  
Numerical Simulation ◽  
Shell Structure ◽  
Composite Shell ◽  
Engineering Practice ◽  
Sublimation Rate ◽  
Long Span ◽  
Static Performance ◽  
New Type ◽  
Ice Sublimation ◽  
Composite Shell Structure

The long-span ice composite shell structure is a new type of ice and snow structure developed in recent years. The engineering practice of ice composite shell shows that sublimation is one of the important reasons for its damage and even collapse. In this paper, we firstly supplemented the existing H-K equation and obtained the revised ice sublimation equation through indoor evaporative plate experiment considering the influence of admixtures and wind speed. Afterwards, combining the simulations of solar radiation and CFD, the numerical simulation of sublimation distribution on the surface of were realized by programming in Grasshopper platform. During sublimation, the thickness of the ice composite shell decreases by 0.38 mm every 10 days and the sublimation rate on the sunny side was 1.7 times that on the shady side. Finally, the static performance and stability of the sublimated ice composite spherical shell were analyzed. After 70 days of sublimation, the thickness of the ice composite shell structure becomes thinner and uneven, which leads its sensitivity to external load increases.

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