Scaled Room Three-Dimensional Computational Fluid Dynamics Simulations

2002 ◽  
Author(s):  
Steven P. O’Halloran ◽  
Mohammad H. Hosni ◽  
B. Terry Beck ◽  
Thomas P. Gielda
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Working Fluid ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Dynamics Simulations

Computational fluid dynamics (CFD) simulations were used to predict three-dimensional flow within a one-tenth-scale room. The dimensions of the scaled room were 732 × 488 × 274 mm (28.8 × 19.2 × 10.8 in.) and symmetry was utilized so that only half of the room was modeled. Corresponding measurements were made under isothermal conditions and water was used as the working fluid instead of air. The commercially available software Fluent was used to perform the simulations. Two turbulence models were used: the renormalization group (RNG) k-ε model and the Reynolds-stress model. The CFD setup is presented in this paper, along with the velocity and turbulent kinetic energy results. The simulation results are compared to previously obtained three-dimensional particle image velocimetry (PIV) measurements made within the same scaled room under similar conditions.

Application of Computational Fluid Dynamics Simulations to the Analysis of Bank Effects in Restricted Waters

2009 ◽  
Vol 62 (3) ◽  
pp. 477-491 ◽  
Author(s):  
D. C. Lo ◽  
Dong-Taur Su ◽  
Jan-Ming Chen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Modelling ◽  
Bank Effect ◽  
Force Increase ◽  
Computational Fluid Dynamics Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Dynamics Simulations ◽  
Yaw Angle ◽  
Vessel Speed

It is well known that vessels operating in the vicinity of a lateral bank experience a significant yaw moment and sway force. This bank effect has a major impact on the manoeuvring properties of the vessel and must therefore be properly understood to ensure the safe passage of the vessel through the restricted waterway. Accordingly, this study performs a series of simulations using commercial FLOW-3D® computational fluid dynamics (CFD) software and the KRISO 3600 TEU container ship model to examine the effects of the vessel speed and distance to bank on the magnitude and time-based variation of the yaw angle and sway force. The results show that for a given vessel speed, the yaw angle and sway force increase as the distance to bank reduces, while for a given distance between the ship and the bank, the yaw angle and sway force increase with an increasing vessel speed. In addition, it is shown that even when a vessel advances at a very low speed, it experiences a significant bank effect when operating in close vicinity to the bank. Overall, the results presented in this study confirm the feasibility of the CFD modelling approach as a means of obtaining detailed insights into the bank effect without the need for time-consuming and expensive ship trials.

Analysis of Velopharyngeal Functions Using Computational Fluid Dynamics Simulations

2019 ◽  
Vol 128 (8) ◽  
pp. 742-748 ◽  
Author(s):  
Hanyao Huang ◽  
Xu Cheng ◽  
Yang Wang ◽  
Dantong Huang ◽  
Yuhao Wei ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Computational Fluid Dynamic Simulation ◽  
Dynamic Features ◽  
Upper Airways ◽  
Dynamic Simulations ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

Objectives: Competent velopharyngeal (VP) function is the basis for normal speech. Understanding how VP structure influences the airflow during speech details is essential to the surgical improvement of pharyngoplasty. In this study, we aimed to illuminate the airflow features corresponding to various VP closure states using computed dynamic simulations. Methods: Three-dimensional models of the upper airways were established based on computed tomography of 8 volunteers. The velopharyngeal port was simulated by a cylinder. Computational fluid dynamics simulations were applied to illustrate the correlation between the VP port size and the airflow parameters, including the flow velocity, pressure in the velopharyngeal port, as well as the pressure in oral and nasal cavity. Results: The airflow dynamics at the velopharynx were maintained in the same velopharyngeal pattern as the area of the velopharyngeal port increased from 0 to 25 mm2. A total of 5 airflow patterns with distinct features were captured, corresponding to adequate closure, adequate/borderline closure (Class I and II), borderline/inadequate closure, and inadequate closure. The maximal orifice area that could be tolerated for adequate VP closure was determined to be 2.01 mm2. Conclusion: Different VP functions are of characteristic airflow dynamic features. Computational fluid dynamic simulation is of application potential in individualized VP surgery planning.

Three-Dimensional, Two-Phase Computational Fluid Dynamics Simulations of Alkaline Diaphragm Water Electrolysis Devices

2020 ◽  
Vol MA2020-02 (38) ◽  
pp. 2495-2495
Author(s):  
Joseph Steven Lopata ◽  
Sanggyu Kang ◽  
Hyun-Seok Cho ◽  
Chang Hee Kim ◽  
Sirivatch Shimpalee
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Water Electrolysis ◽  
Two Phase ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

scholarly journals Optimization and experimental verification of the vibro-impact capsule system in fluid pipeline

2018 ◽  
Vol 233 (3) ◽  
pp. 880-894 ◽  
Author(s):  
Yao Yan ◽  
Yang Liu ◽  
Haibo Jiang ◽  
Zhike Peng ◽  
Alasdair Crawford ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Impact Oscillator ◽  
Pipeline Inspection ◽  
Prototype Development ◽  
Fluid Resistance ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Dynamics Analyses

This paper studies the prototype development of the vibro-impact capsule system aiming for autonomous mobile sensing for pipeline inspection. Self-propelled progression of the system is obtained by employing a vibro-impact oscillator encapsuled in the capsule without the requirement of any external mechanisms, such as wheels, arms, or legs. A dummy capsule prototype is designed, and the best geometric parameters, capsule and cap arc lengths, for minimizing fluid resistance forces are obtained through two-dimensional and three-dimensional computational fluid dynamics analyses, which are confirmed by wind tunnel tests. In order to verify the concept of self-propulsion, both original and optimized capsule prototypes are tested in a fluid pipe. Experimental results are compared with computational fluid dynamics simulations to confirm the efficacy of the vibro-impact self-propelled driving.

scholarly journals Experimental and Numerical Study of Flow Structures Associated With Low Aspect Ratio Elliptical Cavities

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Taravat Khadivi ◽  
Eric Savory
Keyword(s):  
Aspect Ratio ◽  
Particle Image ◽  
Numerical Study ◽  
Three Dimensional ◽  
Reynolds Stress Model ◽  
Cavity Flows ◽  
Low Aspect Ratio ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

The flow regimes associated with 2:1 aspect ratio elliptical planform cavities of varying depth immersed in a turbulent boundary layer at a Reynolds number of 8.7 × 104, based on the minor axis of the cavity, have been quantified from particle image velocimetry measurements and three-dimensional steady computational fluid dynamics simulations (Reynolds stress model closure). Although these elliptical cavity flows have some similarities with nominally two-dimensional and rectangular cases, three-dimensional effects due to the low aspect ratio and curvature of the walls give rise to features exclusive to low aspect ratio elliptical cavities, including formation of cellular structures at intermediate depths and vortex structures within and downstream of the cavity.

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