Numerical Simulation of Yarn Untwisting Mechanism in a Pneumatic Splicer Process

2012 ◽  
Vol 229-231 ◽  
pp. 1721-1724 ◽  
Author(s):  
Xiao Xing ◽  
Guo Ming Ye

For better study of the airflow movement in the untwisting chamber of a pneumatic splicer, this paper uses a commercial computational fluid dynamics software FLUENT to realize the three dimensional numerical simulation for the characteristic of the airflows in the untwisting chamber. A three-dimensional grid and the realizable k- ε tur¬bulence model are used in this simulation. The characteristics of the air flows in different parts of the chamber are analysed according to the computed result. The airflow in the untwisting chamber can be divided into three regions in longitudinal section and two regions in cross section.

2012 ◽  
Vol 446-449 ◽  
pp. 3875-3878
Author(s):  
Bai Feng Ji ◽  
Wei Lian Qu

Thunderstorm microbursts, which are sources of extreme wind loadings in nature, have caused numerous structural failures, especially collapses of transmission tower around the world. Numerical simulation using computational fluid dynamics (CFD) has recently made significant progress in simulating downbursts. In this paper, transient simulation of a three-dimensional moving downburst was studied using computational fluid dynamics simulation method. Transient simulation of a three-dimensional moving downburst was conducted using time-filtered Reynolds Averaged Navier-Stokes (RANS) numerical simulation method. The three-dimensional transient wind field characteristics in a moving downburst were studied in detail. The results indicate that transient wind field characteristics in a moving downburst present quite different characteristics compared with stationary downburst at different heights and radial positions.


Author(s):  
Oscar Darío Monsalve Cifuentes ◽  
Jonathan Graciano Uribe ◽  
Diego Andrés Hincapié Zuluaga

In this work, a 76 mm diameter propeller-type turbine is numerically investigated using a parametric study and computational fluid dynamics. The three-dimensional model of the turbine is modeled using data available in the bibliography. A mesh independence study is carried out utilizing a tetrahedron-based mesh with inflation layers around the turbine blade and the pipe wall. The best efficiency point is determined by the maximum hydraulic efficiency of 64.46 %, at a flow rate of 9.72x10-3 m3/s , a head drop of 1.76 m, and a mechanical power of 107.83 W. Additionally, the dimensionless distance y+, pressure, and velocity contours are shown.


2013 ◽  
Vol 427-429 ◽  
pp. 262-265
Author(s):  
De Fan Zhou ◽  
Qi Hui Zhou ◽  
Xiu Li Meng ◽  
Xiao Dong Yu ◽  
Zhi Qiang Wang ◽  
...  

In order to solve the mechanical deformation of the hydrostatic center rest, a numerical simulation concerning pressure field of hydrostatic center rest is studied. CFX of ANSYS has been used to compute three-dimensional pressure field of gap fluid between workpiece and bearing pillow. This research analyzes the influence of rotation speed on the bearing pressure performance according to lubricating theory and computational fluid dynamics, and it has revealed its pressure distribution law of gap oil film. Results indicate that an improved characteristic will be affected by rotation speed easily, and oil cavity pressure increases by gradually with rotation speed enhancing. The reliability of a hydrostatic center rest can be predicted through this method.


2014 ◽  
Vol 602-605 ◽  
pp. 650-652
Author(s):  
Hui Li ◽  
Rui Li Wang

Based on the principle and method of computational fluid dynamics (CFD), using the software, FLUENT, the inner flow field in a mixed-flow stirred reactor was simulated and the flow details were studied roundly. This article analyzed the three-dimensional velocity field distribution and testified the reliability of numerical simulation to a certain extent. The simulated effect was proved effective. The results of this paper provided a good base and reference for the further research of the stirred reactor.


Author(s):  
Anup Fouzder ◽  
Arash Zakeri ◽  
Bipul Hawlader

The critical location for fatigue damage in Steel Catenary Riser’s (SCR’s) often occurs within the Touchdown Zone (TDZ), where cyclic interaction of the riser with the seabed takes place. Riser-fluid-soil interaction at the TDZ is a complex phenomenon. In this study, Computational Fluid Dynamics (CFD) technique is used to investigate the velocity field and suction forces during riser-fluid-soil interaction for a two-dimensional cross section of 0.10 m diameter SCR at TDZ. Numerical simulation shows that the suction forces at the bottom of the riser are high enough to pull the clay upward when it departs from the seabed during the heave action. The influence of suction and water on trench formation mechanism is discussed.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hassam Nasarullah Chaudhry ◽  
John Kaiser Calautit ◽  
Ben Richard Hughes

The effect of wind distribution on the architectural domain of the Bahrain Trade Centre was numerically analysed using computational fluid dynamics (CFD). Using the numerical data, the power generation potential of the building-integrated wind turbines was determined in response to the prevailing wind direction. The three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations along with the momentum and continuity equations were solved for obtaining the velocity and pressure field. Simulating a reference wind speed of 6 m/s, the findings from the study quantified an estimate power generation of 6.4 kW indicating a capacity factor of 2.9% for the benchmark model. At the windward side of the building, it was observed that the layers of turbulence intensified in inverse proportion to the height of the building with an average value of 0.45 J/kg. The air velocity was found to gradually increase in direct proportion to the elevation with the turbine located at higher altitude receiving maximum exposure to incoming wind. This work highlighted the potential of using advanced computational fluid dynamics in order to factor wind into the design of any architectural environment.


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