scholarly journals A Method of Accelerating the Convergence of Computational Fluid Dynamics for Micro-Siting Wind Mapping

Computation ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 22 ◽  
Author(s):  
Kim
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Wind Direction ◽  
Initial Conditions ◽  
Atmospheric Stability ◽  
Computation Time ◽  
Initial Condition ◽  
Simulation Domain ◽  
Computational Fluid Dynamics Cfd

To assess wind resources, a number of simulations should be performed by wind direction, wind speed, and atmospheric stability bins to conduct micro-siting using computational fluid dynamics (CFD). This study proposes a method of accelerating CFD convergence by generating initial conditions that are closer to the converged solution. In addition, the study proposes the ‘mirrored initial condition’ (IC) using the symmetry of wind direction and geography, the ‘composed IC’ using the vector composition principle, and the ‘shifted IC’ which assumes that the wind speed vectors are similar in conditions characterized by minute differences in wind direction as the well-posed initial conditions. They provided a significantly closer approximation to the converged flow field than did the conventional initial condition, which simply assumed a homogenous atmospheric boundary layer over the entire simulation domain. The results of this study show that the computation time taken for micro-siting can be shortened by around 35% when conducting CFD with 16 wind direction sectors by mixing the conventional and the proposed ICs properly.

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.

scholarly journals The Protect Air Film of an Exterior Window

2021 ◽  
Author(s):  
Sanaz Dianat
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Glass Temperature ◽  
Experimental Procedure ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Air Film ◽  
The Impact

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed

scholarly journals The Protect Air Film of an Exterior Window

2021 ◽  
Author(s):  
Sanaz Dianat
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Glass Temperature ◽  
Experimental Procedure ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Air Film ◽  
The Impact

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed

Computational Study of Single-Sided Ventilation Through a 3-Dimensional Room With Rounded Edges

2013 ◽  
Author(s):  
A. Idris ◽  
B. P. Huynh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Flow Pattern ◽  
Flow Rate ◽  
Software Package ◽  
Computational Study ◽  
Ventilation Rate ◽  
3 Dimensional ◽  
Computational Fluid Dynamics Cfd

A commercial Computational Fluid Dynamics (CFD) software package is used to investigate numerically a 3-dimensional rectangular-box room with rounded edges. The room has all its window openings located on one wall only. The standard K-ε turbulence model is used. Air’s flow rate and flow pattern are considered in terms of wind speed and the openings’ characteristics, such as their number, location, size and shape. Especially, comparison with ventilation rate corresponding to when the room edges are sharp is made; and thereby the effects of the edges being rounded are examined.

scholarly journals Mapping flow distortion on oceanographic platforms using computational fluid dynamics

Ocean Science ◽  
2013 ◽  
Vol 9 (5) ◽  
pp. 855-866 ◽  
Author(s):  
N. O'Sullivan ◽  
S. Landwehr ◽  
B. Ward
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Close Agreement ◽  
Velocity Fields ◽  
Experimental Measurements ◽  
Flow Distortion ◽  
Direct Measurements ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up

Abstract. Wind speed measurements over the ocean on ships or buoys are affected by flow distortion from the platform and by the anemometer itself. This can lead to errors in direct measurements and the derived parametrisations. Here we computational fluid dynamics (CFD) to simulate the errors in wind speed measurements caused by flow distortion on the RV Celtic Explorer. Numerical measurements were obtained from the finite-volume CFD code OpenFOAM, which was used to simulate the velocity fields. This was done over a range of orientations in the test domain from −60 to +60° in increments of 10°. The simulation was also set up for a range of velocities, ranging from 5 to 25 m s−1 in increments of 0.5 m s−1. The numerical analysis showed close agreement to experimental measurements.

Numerical Investigation of Recirculation of Air-Cooled Condensers for a Large Power Plant

2012 ◽  
Vol 516-517 ◽  
pp. 355-359
Author(s):  
Wan Li Zhao ◽  
Wen Zhou Yan ◽  
Can Bing Xu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Power Plant ◽  
Wind Direction ◽  
Rotational Speed ◽  
Power Plants ◽  
Normal Operation ◽  
Large Power ◽  
Air Cooled Condensers

In order to minimize the recirculation to ensure normal operation of the air-cooled condensers (ACC) system, the recirculation phenomenon and its dependence on ambient winds are numerically simulated by using the computational fluid dynamics code, FLUENT. Under the constant ambient temperature, the effects of different wind speed and wind direction on the recirculation are qualitatively considered by applying the concept of the recirculation rate. The mechanism of occurrence of recirculation are presented and analyzed. It was found that when considering about the existing and normally operating power plants, the recirculation is more sensitive to wind direction and wind speed. Based on the above results, three improved measures 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 reduce the recirculation.

Airflow Modeling and Simulation Required in CBRN Collective Protection Design

2016 ◽  
Vol 22 (3) ◽  
pp. 649-653 ◽  
Author(s):  
Claudiu Lăzăroaie ◽  
Teodora Zecheru ◽  
Ciprian Său ◽  
Tudor Cherecheş
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Flow Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Strategic Position ◽  
Industrial Materials ◽  
Materials Used ◽  
Commercial Applications ◽  
Air Circulation

Abstract Many CBRN agents are very difficult to detect and identify, due to the fact that most technologies, equipment and materials used for their obtainment have also commercial applications. One possibility to counteract such threats, both for military and civilians, is to use systems of collective protection (COLPRO), which must be manufactured from materials that can withstand not only the action of CBRN agents, but, as much as possible, toxic industrial materials (TIMs). The computational fluid dynamics (CFD) study of the atmosphere in the neighbourhood of the COLPRO tent and the air flow dynamics inside the tent give all the necessary data regarding the effect of air circulation on the entire COLPRO system. Based on this study, a favourable orientation of the COLPRO tent may be established relatively to the strategic position of the troops or the civilian groups, versus statistical wind speed, direction and charge.

scholarly journals Heterogeneous Computing (CPU–GPU) for Pollution Dispersion in an Urban Environment

Computation ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 3 ◽  
Author(s):  
Gonzalo Fernandez ◽  
Mariana Mendina ◽  
Gabriel Usera
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Urban Environment ◽  
Heterogeneous Computing ◽  
Dispersion Model ◽  
Urban Environments ◽  
Pollution Dispersion ◽  
Simulation Domain ◽  
Computational Fluid Dynamics Cfd ◽  
Computational Resources

The use of Computational Fluid Dynamics (CFD) to assist in air quality studies in urban environments can provide accurate results for the dispersion of pollutants. However, due to the computational resources needed, simulation domain sizes tend to be limited. This study aims to improve the computational efficiency of an emission and dispersion model implemented in a CPU-based solver by migrating it to a CPU–GPU-based one. The migration of the functions that handle boundary conditions and source terms for the pollutants is explained, as well as the main differences present in the solvers used. Once implemented, the model was used to run simulations with both engines on different platforms, enabling the comparison between them and reaching promising time improvements in favor of the use of GPUs.

scholarly journals Computational Fluid Dynamics Support for Fontan Planning in Minutes, Not Hours: The Next Step in Clinical Pre-Interventional Simulations

2021 ◽  
Author(s):  
Petter Frieberg ◽  
Nicolas Aristokleous ◽  
Pia Sjöberg ◽  
Johannes Töger ◽  
Petru Liuba ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computation Time ◽  
Left Pulmonary Artery ◽  
Cfd Modeling ◽  
Resonance Imaging ◽  
Computational Fluid Dynamics Cfd ◽  
Magnetic Resonance Imaging Mri ◽  
Cfd Method ◽  
Fontan Patients

AbstractComputational fluid dynamics (CFD) modeling may aid in planning of invasive interventions in Fontan patients. Clinical application of current CFD techniques is however limited by complexity and long computation times. Therefore, we validated a “lean” CFD method to magnetic resonance imaging (MRI) and an “established” CFD method, ultimately aiming to reduce complexity to enable predictive CFD during ongoing interventions. Fifteen Fontan patients underwent MRI for CFD modeling. The differences between lean and established approach, in hepatic and total flow percentage to the left pulmonary artery (%LPA), power loss and relative wall shear stress area were 1.5 ± 4.0%, -0.17 ± 1.1%, -0.055 ± 0.092 mW and 1.1 ± 1.4%. Compared with MRI, the lean and established method showed a bias in %LPA of -1.9 ± 3.4% and -1.8 ± 3.1%. Computation time was for the lean and established approach 3.0 ± 2.0 min and 7.0 ± 3.4 h, respectively. We conclude that the proposed lean method provides fast and reliable results for future CFD support during interventions. Graphical abstract

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