scholarly journals Numerical Investigation for the Resin Filling Behavior during Ultraviolet Nanoimprint Lithography of Subwavelength Moth-Eye Nanostructure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 799
Author(s):  
Yuanchi Cui ◽  
Xuewen Wang ◽  
Chengpeng Zhang ◽  
Jilai Wang ◽  
Zhenyu Shi
Keyword(s):  
Simulation Model ◽  
Nanoimprint Lithography ◽  
Cfd Simulation ◽  
Boundary Slip ◽  
Accurate Analysis ◽  
Inlet Velocity ◽  
Filling Height ◽  
Proposed Model ◽  
Good Consistency ◽  
Computational Fluid Dynamics Cfd

Accurate analysis of the resin filling process into the mold cavity is necessary for the high-precision fabrication of moth-eye nanostructure using the ultraviolet nanoimprint lithography (UV-NIL) technique. In this research, a computational fluid dynamics (CFD) simulation model was proposed to reveal resin filling behavior, in which the effect of boundary slip was considered. By comparison with the experimental results, a good consistency was found, indicating that the simulation model could be used to analyze the resin filling behavior. Based on the proposed model, the effects of process parameters on resin filling behavior were analyzed, including resin viscosity, inlet velocity and resin thickness. It was found that the inlet velocity showed a more significant effect on filling height than the resin viscosity and thickness. Besides, the effects of boundary conditions on resin filling behavior were investigated, and it was found the boundary slip had a significant influence on resin filling behavior, and excellent filling results were obtained with a larger slip velocity on the mold side. This research could provide guidance for a more comprehensive understanding of the resin filling behavior during UV-NIL of subwavelength moth-eye nanostructure.

The Simulation and Validation of Smoldering in a Burning Cave

2019 ◽  
Vol 62 (5) ◽  
pp. 1103-1111
Author(s):  
Zhanyang Xu ◽  
Wenhe Liu ◽  
Tieliang Wang ◽  
Yikui Bai ◽  
Wei Yu ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cfd Simulation ◽  
Rapid Heating ◽  
Cfd Modeling ◽  
Inlet Velocity ◽  
Air Inlet ◽  
Computational Fluid Dynamics Cfd

Abstract. In this study, simulations of forward and opposed smoldering in a burning cave were carried out by computational fluid dynamics (CFD) modeling. The fuel in the burning cave was considered a multiphase porous medium with uniform heating. The heat release rates for forward and opposed smoldering in the burning cave were also calculated with an inverse method based on the CFD model. Experiments were conducted to validate the accuracy of the simulation model and the heating performance of the burning cave. The results showed that the model accurately predicted the temperature distributions in the burning cave with an error of 5% to 10% compared to the experimental results. Calculations showed that the heat release rate was 850 W m-3 for forward smoldering and 500 W m-3 for opposed smoldering with an air inlet velocity of 0.1 m s-1. When the air inlet velocity was increased to 0.3 m s-1, the heat release rate increased from 850 to 2,000 W m-3 for forward smoldering and from 500 to 1,000 W m-3 for opposed smoldering. Forward smoldering produced rapid heating in the burning cave but caused uneven temperature distribution on the roof. Conversely, opposed smoldering heated the burning cave at a slower rate, but the temperature distribution on the roof was uniform. Keywords: Burning cave, CFD simulation, Multiphase porous media, Smoldering.

Study on Inner Vortex in a Hydrocyclone through Numerical Simulation

2013 ◽  
Vol 788 ◽  
pp. 228-232
Author(s):  
Zhuo Lun Cen ◽  
Ji Gang Zhao ◽  
Ben Xian Shen
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Swirling Flow ◽  
Small Diameter ◽  
Ansys Fluent ◽  
Detailed Understanding ◽  
Inlet Velocity ◽  
Computational Fluid Dynamics Cfd

Hydrocyclones provide an economic and efficient process of separation in many industries, but there has been little detailed understanding of the strong swirling flow prevailing inside the device, especially the complex inner vortex. This work presented a computational fluid dynamics (CFD) simulation to predict and to evaluate the effects of inlet velocity and the diameter of overflow tube on the inner vortex. The calculation was carried out using commercial CFD code Ansys Fluent 14.0. The results obtained demonstrates both an overlarge inlet velocity and a too small diameter of overflow tube lead to a severe backmixing at the head of hydrocyclone, moreover the latter results in a disorder and unstructured inner vortex.

scholarly journals CFD Simulation Model of Salt Wedge Propagation

2022 ◽  
Vol 28 (1) ◽  
pp. 76-85
Author(s):  
Aya kh. Shaheed ◽  
Riyadh Z. Azzubaidi
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Cfd Simulation ◽  
Laboratory Data ◽  
Cfd Model ◽  
Salt Wedge ◽  
Laboratory Results ◽  
Computational Fluid Dynamics Cfd ◽  
Bed Slope ◽  
Good Agreement

This study aims to numerically simulate the flow of the salt wedge by using computational fluid dynamics, CFD. The accuracy of the numerical simulation model was assessed against published laboratory data. Twelve CFD model runs were conducted under the same laboratory conditions. The results showed that the propagation of the salt wedge is inversely proportional to the applied freshwater discharge and the bed slope of the flume.  The maximum propagation is obtained at the lowest discharge value and the minimum slope of the flume. The comparison between the published laboratory results and numerical simulation shows a good agreement. The range of the relative error varies between 0 and 16% with an average of 2% and a root mean square error of 0.18. Accordingly, the CFD software is quite valid to simulate the propagation of the salt wedge. 

scholarly journals Computational fluid dynamics (CFD) simulation analysis on retinal gas cover rates using computational eye models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Makoto Gozawa ◽  
Yoshihiro Takamura ◽  
Tomoe Aoki ◽  
Kentaro Iwasaki ◽  
Masaru Inatani
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Fluid Dynamic ◽  
Fluid Analysis ◽  
Intraocular Gas ◽  
Pars Plana ◽  
Computational Fluid Dynamics Cfd ◽  
Multiple Breaks ◽  
Gas Volume ◽  
Wall Wettability

AbstractWe investigated the change in the retinal gas cover rates due to intraocular gas volume and positions using computational eye models and demonstrated the appropriate position after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachments (RRDs). Computational fluid dynamic (CFD) software was used to calculate the retinal wall wettability of a computational pseudophakic eye models using fluid analysis. The model utilized different gas volumes from 10 to 90%, in increments of 10% to the vitreous cavity in the supine, sitting, lateral, prone with closed eyes, and prone positions. Then, the gas cover rates of the retina were measured in each quadrant. When breaks are limited to the inferior retina anterior to the equator or multiple breaks are observed in two or more quadrants anterior to the equator, supine position maintained 100% gas cover rates in all breaks for the longest duration compared with other positions. When breaks are limited to either superior, nasal, or temporal retina, sitting, lower temporal, and lower nasal position were maintained at 100% gas cover rates for the longest duration, respectively. Our results may contribute to better surgical outcomes of RRDs and a reduction in the duration of the postoperative prone position.

scholarly journals Computational Fluid Dynamics (CFD) Simulation on Mixing in T-Shaped Micromixer

2020 ◽  
Vol 932 ◽  
pp. 012006
Author(s):  
S N A Ahmad Termizi ◽  
C Y Khor ◽  
M A M Nawi ◽  
Nurlela Ahmad ◽  
Muhammad Ikman Ishak ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Computational Fluid Dynamics Cfd

scholarly journals Boundary slip measurement and mechanism analysis in ultraviolet nanoimprint lithography of subwavelength moth-eye nanostructure

Procedia CIRP ◽  
2020 ◽  
Vol 95 ◽  
pp. 155-160
Author(s):  
Chengpeng Zhang ◽  
Shuai Chen ◽  
Zhaoliang Jiang ◽  
Cheng Zhang ◽  
Li Zhao
Keyword(s):  
Nanoimprint Lithography ◽  
Mechanism Analysis ◽  
Boundary Slip

Load Characteristics of Steel and Concrete Tubular Members Under Jet Fire: An Experimental and Numerical Study

2010 ◽  
Author(s):  
Jeong Hyo Park ◽  
Bong Ju Kim ◽  
Jung Kwan Seo ◽  
Jae Sung Jeong ◽  
Byung Keun Oh ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Numerical Study ◽  
Fire Load ◽  
Adiabatic Wall ◽  
Fire Engineering ◽  
Ansys Cfx ◽  
Design Values ◽  
Computational Fluid Dynamics Cfd ◽  
Load Characteristics ◽  
Set Up

The aim of this study was to evaluate the load characteristics of steel and concrete tubular members under jet fire, with the motivation to investigate the jet fire load characteristics in FPSO topsides. This paper is part of Phase II of the joint industry project on explosion and fire engineering of FPSOs (EFEF JIP) [1]. To obtain reliable load values, jet fire tests were carried out in parallel with a numerical study. Computational fluid dynamics (CFD) simulation was used to set up an adiabatic wall boundary condition for the jet fire to model the heat transfer mechanism. A concrete tubular member was tested under the assumption that there is no conduction effect from jet fire. A steel tubular member was tested and considered to transfer heat through conduction, convection, and radiation. The temperature distribution, or heat load, was analyzed at specific locations on each type of member. ANSYS CFX [2] and Kameleon FireEx [3] codes were used to obtain similar fire action in the numerical and experimental methods. The results of this study will provide a useful database to determine design values related to jet fire.

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

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