Application of Ghost Body-Cell Method on Adaptively Refined Cartesian Grid in Computational Fluid Dynamics

2013 ◽  
Vol 300-301 ◽  
pp. 775-780
Author(s):  
Yu Qi Han ◽  
Shu Xin Cui ◽  
Yong Wang ◽  
Ge Gao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Cartesian Grid ◽  
Time Step ◽  
Body Cell ◽  
Cell Method ◽  
Cut Cell ◽  
Grid Approach ◽  
Volume Method

Least-squares fitting was employed to interpolate the reflect point, ghost body-cell method (GBCM) was applied to quadtree-based adaptively refined Cartesian grid approach, and finite volume method was employed to solve Euler equations. Shape of cut cell kept in accordance with that in the flow field which efficiently relieved the time step restriction of small cut cells. Flows around a circular cylinder and the double NACA0012 airfoils are simulated and compared with published structured grid results, which show flow field around complex geometries is adequately resolved resort to GBCM approach on adaptively refined Cartesian grid in computational fluid dynamics (CFD).

Singular Cell Adaptive Method for Adaptively Refined Cartesian Grid in the Simulation of Flow around Airfoil

2013 ◽  
Vol 275-277 ◽  
pp. 537-542
Author(s):  
Yu Qi Han ◽  
Lin Gao ◽  
Ge Gao
Keyword(s):  
Flow Field ◽  
Transonic Flow ◽  
Subsonic Flow ◽  
Solid Wall ◽  
Adaptive Method ◽  
Current Approach ◽  
Cartesian Grid ◽  
Time Step ◽  
Cut Cell ◽  
Volume Method

A novel adaptive method for singular geometric regions was proposed. Combined with conventional cut cell adaption, curvature cell adaption and solution adaption, adaptively refined Cartesian grid was automatically generated after geometries had been specified by users. Solid wall boundary was implemented by ghost body-cell method which efficiently relieved the time step restriction of small cut cells. Flow field was well resolved on adaptively refined Cartesian grid with finite volume method. Transonic flow around the RAE2822 airfoil and subsonic flow around the Suddhoo four-element airfoil are carefully investigated, which validate the efficiency of current approach and its feasibility in complicated geometric regions.

scholarly journals Simulasi Lemari Pengering Tenga Surya Dengan Prisma Kaca Menggunakan Computational Fluid Dynamics

2021 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Lohdy Diana ◽  
Arrad Ghani Safitra ◽  
Fifi Hesty Sholihah ◽  
Ahmad Taufiqurrahman Azhar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Time Step ◽  
Volume Method

<p>Lemari pengering merupakan bagian penting pada pemanas udara tenaga surya. Lemari pengering diharapkan mampu menyimpan panas dalam waktu yang lama. Hal tersebut menyebabkan analisa thermal pada lemari pengering perlu dilakukan. Tujuan dari penelitian ini adalah untuk mengetahui karakteristik termal dan aliran yang terjadi pada lemari pengering. Karakteristik tersebut antara lain distribusi temperatur, perubahan temperatur dan kecepatan, dan pola aliran udara. Metode yang digunakan pada penelitian ini adalah <em>Finite Volume Method</em> berupa simulasi menggunakan software komputasi fluida atau <em>Computational Fluid Dynamics</em>, simulasi menggunakan model tiga dimensi pada kondisi transient dengan time step 0.015. Data simulasi diambil saat 5 detik, 15 detik, 25 detik, dan 35 detik. Hasil simulasi diperoleh perubahan distribusi temperatur udara terhadap waktu yang terjadi pada bidang XY dan bidang XZ lemari pengering. Berdasarkan hasil simulasi diketahui terjadi penurunan temperatur udara. Temperatur udara tertinggi terjadi pada bagian bawah lemari pengering dengan temperatur udara sebesar 331 K. Prisma kaca pada bagian atas lemari pengering mampu memberikan panas pada udara. Terjadi aliran balik di dalam lemari pengering yang menyebabkan udara panas dari saluran masukkan tidak terdistribusi merata.</p>

Construction Ventilation Scheme Optimization of Underground Main Powerhouse Based on CFD

2013 ◽  
Vol 368-370 ◽  
pp. 619-623
Author(s):  
Zhen Liu ◽  
Xiao Ling Wang ◽  
Ai Li Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Air Flow ◽  
Scheme Optimization ◽  
Pressure Distributions ◽  
Air Volume ◽  
Computational Fluid Dynamics Cfd ◽  
Traditional Construction ◽  
Ventilation Scheme

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.

scholarly journals Effect of Doppler flow meter position on discharge measurement in surcharged manholes

2017 ◽  
Vol 77 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Haoming Yang ◽  
David Z. Zhu ◽  
Yanchen Liu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Flow Regimes ◽  
Flow Meter ◽  
Flow Meters ◽  
Flow Discharge ◽  
Doppler Flow ◽  
Sewer Systems ◽  
Computational Fluid Dynamics Cfd

Abstract Determining the proper installation location of flow meters is important for accurate measurement of discharge in sewer systems. In this study, flow field and flow regimes in two types of manholes under surcharged flow were investigated using a commercial computational fluid dynamics (CFD) code. The error in measuring the flow discharge using a Doppler flow meter (based on the velocity in a Doppler beam) was then estimated. The values of the corrective coefficient were obtained for the Doppler flow meter at different locations under various conditions. Suggestions for selecting installation positions are provided.

The Effect of Different Turbulence Models on the Emitter Discharge by Using Computational Fluid Dynamics

2013 ◽  
Vol 662 ◽  
pp. 586-590
Author(s):  
Gang Lu ◽  
Qing Song Yan ◽  
Bai Ping Lu ◽  
Shuai Xu ◽  
Kang Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Turbulence Models ◽  
Experimental Results ◽  
Turbulent Model ◽  
Simulation Results ◽  
Rsm Model ◽  
Dynamics Method ◽  
Emitter Discharge

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.

Numerical Investigation of Thermal Flow Field of Air-Cooled Condensers for Yongshou Plant

2012 ◽  
Vol 248 ◽  
pp. 391-394
Author(s):  
Wen Zhou Yan ◽  
Wan Li Zhao ◽  
Qiu Yan Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Power Plant ◽  
Flow Field ◽  
Wind Direction ◽  
Rotational Speed ◽  
Power Plants ◽  
Thermal Flow ◽  
Air Cooled Condensers

By using the computational fluid dynamics code, FLUENT, Numerically simulation is investigated for Youngshou power plant. Under the constant ambient temperature, the effects of different wind speed and wind direction on the thermal flow field are qualitatively considered. It was found that when considering about the existing and normally operating power plants, the thermal flow field is more sensitive to wind direction and wind speed. Based on the above results, three improved measures such as: increasing the wind-wall height and accelerating the rotational speed of the fans near the edge of the ACC platform and lengthen or widen the platform are developed to effectively improving the thermal flow field, and enhanced the heat dispersal of ACC.

CFD Leakage Predictions of Unworn and Worn Labyrinth Seals With and Without Tooth Axial Offset

2017 ◽  
Author(s):  
Hasham H. Chougule ◽  
Alexander Mirzamoghadam
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Modeling ◽  
Steady State ◽  
Flow Field ◽  
Labyrinth Seals ◽  
Small Clearance ◽  
Total Leakage ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Deflection

The objective of this study is to develop a Computational Fluid Dynamics (CFD) based methodology for analyzing and predicting leakage of worn or rub-intended labyrinth seals during operation. The simulations include intended tooth axial offset and numerical modeling of the flow field. The purpose is to predict total leakage through the seal when an axial tooth offset is provided after the intended/unintended rub. Results indicate that as expected, the leakage for the in-line worn land case (i.e. tooth under rub) is higher compared to unworn. Furthermore, the intended rotor/teeth forward axial offset/shift with respect to the rubbed land reduces the seal leakage. The overall leakage of a rubbed seal with axial tooth offset is observed to be considerably reduced, and it can become even less than a small clearance seal designed not to rub. The reduced leakage during steady state is due to a targeted smaller running gap because of tooth offset under the intended/worn land groove shape, higher blockages, higher turbulence and flow deflection as compared to worn seal model without axial tooth offset.

Flow Field and Temperature Field in GaN-MOCVD Reactor Based on Computational Fluid Dynamics Modeling

2018 ◽  
Vol 35 (9) ◽  
pp. 098101
Author(s):  
Shu-Zhe Mei ◽  
Quan Wang ◽  
Mei-Lan Hao ◽  
Jian-Kai Xu ◽  
Hong-Ling Xiao ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Field ◽  
Flow Field ◽  
Dynamics Modeling ◽  
Computational Fluid Dynamics Modeling ◽  
Mocvd Reactor

A Condensed Phase Computational Fluid Dynamics Model for Polymer Melt Flow

2008 ◽  
Author(s):  
Qing Tang ◽  
Michael Bockelie
Keyword(s):  
Fluid Dynamics ◽  
Heat Flux ◽  
Computational Fluid Dynamics ◽  
Condensed Phase ◽  
Stokes Equations ◽  
Free Surface Flows ◽  
Polymer Materials ◽  
High Heat Flux ◽  
Time Step ◽  
Temperature Dependent Viscosity

This paper presents a condensed phase computational fluid dynamics (CFD) based tool for modeling the processes of melting, flow and gasification of thermoplastic materials exposed to a high heat flux. Potential applications of the tool include investigating the behavior of polymer materials commonly used in personal computers and computer monitors if exposed to an intense heat flux, such as occurs during a fire. The finite-volume based model uses a three-dimensional body-fitted time dependent grid formulation to solve the unsteady Navier Stokes equations. A multi-grid method is used to accelerate convergence at each time step. Sub-models are included to describe the temperature dependent viscosity relationship and in-depth gasification and absorption of thermoplastic materials, free surface flows and surface tension. A series of test cases have been performed and the model results are compared to experimental data to investigate the impacts of different sub-models, boundary conditions, material properties and problem configurations on the accuracy, efficiency and applicability of the modeling tool.

Numerical Analysis of the LCS 2 airwake to understand potential interactions during helipcopter operations

2015 ◽  
Author(s):  
Brent S. Paul
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Analysis ◽  
Flow Field ◽  
Ship Design ◽  
It Impacts ◽  
Flight Envelope ◽  
Computational Fluid Dynamics Cfd ◽  
Potential Interactions ◽  
Flight Deck

The successful integration of aviation capabilities aboard ships is a complex endeavor that must balance ship design with the flight envelope of the helicopter. This can be particularly important when considering air wakes and other flow around the superstructure as it impacts the flight deck. This flow can generate unsteady structures that may interfere with safe helicopter operations. Computational fluid dynamics (CFD) is commonly used to characterize the flow field and assess potential impacts to the flight envelope, which can be used to help define an operating envelope for helicopter operations.

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