scholarly journals Influence of Calculation Domain Size on Numerical Simulation Results for Complex Terrain Wind Fields

2019 ◽  
Vol 12 (2) ◽  
pp. 59-66
Author(s):  
Lian Shen ◽  
◽  
Chenglong Wei ◽  
Chunsheng Cai ◽  
Xiaoyan Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Complex Terrain ◽  
Domain Size ◽  
Wind Fields ◽  
Calculation Domain ◽  
Simulation Results

Effect of Plenum Chamber Configuration on Airflow Uniformity in Unidirectional Flow Cleanrooms

1994 ◽  
Vol 37 (4) ◽  
pp. 21-27
Author(s):  
Guoping Xie ◽  
Yoshihide Suwa
Keyword(s):  
Numerical Simulation ◽  
Numerical Method ◽  
Pressure Loss ◽  
Simulation Method ◽  
Calculation Domain ◽  
Plenum Chamber ◽  
Unidirectional Flow ◽  
Numerical Simulation Method ◽  
Airflow Distribution ◽  
Simulation Results

Uniformity of airflow distribution in a unidirectional flow cleanroom has been studied experimentally and numerically. The influence of the height of the plenum chamber and the velocity of airflow introduced into the chamber on the airflow uniformity are investigated experimentally. In addition, a numerical simulation method to predict airflow uniformity is proposed, taking into account the characteristics of the pressure loss of the filter. The calculation domain in this study includes not only the cleanroom but also the plenum chamber and the exhaust chamber. The validity of the numerical method is also verified by comparing the simulation results with the experiments. Finally, the numerical method is used to obtain an appropriate height for the plenum chamber.

A simple and efficient procedure for the numerical simulation of wind fields in complex terrain

2007 ◽  
Vol 125 (3) ◽  
pp. 417-439 ◽  
Author(s):  
Massimiliano Burlando ◽  
Luigi Carassale ◽  
Emilia Georgieva ◽  
Corrado F. Ratto ◽  
Giovanni Solari
Keyword(s):  
Numerical Simulation ◽  
Complex Terrain ◽  
Wind Fields ◽  
Efficient Procedure

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

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 Experiment and simulation about the effect of wear-ring abrasion on the performance of a marine centrifugal pump

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Vibration Velocity ◽  
Test Results ◽  
Obvious Effect ◽  
Performance Change ◽  
Pump Test ◽  
Simulation Results ◽  
Axis Passing

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.

scholarly journals Development of Depth-Limited Wave Boundary Layers over a Smooth Bottom

2020 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Hitoshi Tanaka ◽  
Nguyen Xuan Tinh ◽  
Xiping Yu ◽  
Guangwei Liu
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Boundary Layers ◽  
Wave Motion ◽  
Numerical Study ◽  
Experiment Data ◽  
Tidal Motion ◽  
Long Period ◽  
Simulation Results ◽  
Wave Boundary

A theoretical and numerical study is carried out to investigate the transformation of the wave boundary layer from non-depth-limited (wave-like boundary layer) to depth-limited one (current-like boundary layer) over a smooth bottom. A long period of wave motion is not sufficient to induce depth-limited properties, although it has simply been assumed in various situations under long waves, such as tsunami and tidal currents. Four criteria are obtained theoretically for recognizing the inception of the depth-limited condition under waves. To validate the theoretical criteria, numerical simulation results using a turbulence model as well as laboratory experiment data are employed. In addition, typical field situations induced by tidal motion and tsunami are discussed to show the usefulness of the proposed criteria.

Simulation of the wind fields over complex terrain with coupling of CFD and WRF

2021 ◽  
pp. 1-12
Author(s):  
Xiaoyu Luo ◽  
Yiwen Cao
Keyword(s):  
Wind Speed ◽  
Wind Field ◽  
Complex Terrain ◽  
Civil Engineering ◽  
Meteorological Data ◽  
Mass Conservation ◽  
Coupling Method ◽  
Wind Fields ◽  
Civil Structures ◽  
Civil Engineers

In the field of civil engineering, the meteorological data available usually do not have the detailed information of the wind near a certain site. However, the detailed information of the wind field during typhoon is important for the wind-resistant design of civil structures. Furthermore, the resolution of the meteorological data available by the civil engineers is too coarse to be applicable. Therefore it is meaningful to obtain the detailed information of the wind fields based on the meteorological data provided by the meteorological department. Therefore, in the present study, a one-way coupling method between WRF and CFD is adopted and a method to keep the mass conservation during the simulation in CFD is proposed. It is found that using the proposed one-way coupling method, the predicted wind speed is closer to the measurement. And the curvature of the wind streamline during typhoon is successfully reproduced.

Design of Impeller of Centrifugal Compressor for Water-Air Engine

2014 ◽  
Vol 496-500 ◽  
pp. 642-645
Author(s):  
Yun Wang ◽  
Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Power System ◽  
Centrifugal Compressor ◽  
Centrifugal Impeller ◽  
3D Design ◽  
Pump Impeller ◽  
Aero Engine ◽  
Simulation Results

In view of power system in water-air UAV requirements, combine with the centrifugal impeller for aero-engine and the pump impeller. The design of a impeller of centrifugal compressor can work on the air and in the water for the new concept of air-water engine. With 3D design and a 3D CFD solver on it and analysis the results of numerical simulation. Results show that the designed impeller successfully reached the goal on the air and in the water. The experiences accumulated in this procedure are useful for similar impeller aerodynamic designs.

The Influence of the Convective Terms Discretization Scheme on the Simulation Results of Architectural Numerical Wind Tunnel

2012 ◽  
Vol 204-208 ◽  
pp. 4884-4887
Author(s):  
Jian Feng Wu ◽  
Cai Hua Wang ◽  
Chang Li Song
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Building Structures ◽  
Discretization Scheme ◽  
Shape Coefficient ◽  
Fluent Software ◽  
Actual Operation ◽  
Simulation Results ◽  
Load Shape ◽  
Numerical Wind Tunnel Method

The numerical simulation of construction is to obtain the desired accuracy. It depends on the theoretical basis of the calculator and selection of the various important factors in the actual operation. For this problem, this paper adopting the current code for the design of building structures as the comparison standard, using the FLUENT software, taking the numerical simulation results of a high building’s wind load shape coefficient of for example, discussing the influence of four kinds of the convective terms discretization scheme, respectively the first-order upwind, the second order upwind , power law and Quadratic upwind interpolation for convective kinematics, on the simulation results of architectural numerical wind tunnel, provides the reference for the rational use of numerical wind tunnel method.

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