Three-Dimensional Simulation of Hydrodynamics in a Rotating Disc Contactor using Computational Fluid Dynamics

2009 ◽  
Vol 32 (1) ◽  
pp. 93-102 ◽  
Author(s):  
S. Ghaniyari-Benis ◽  
N. Hedayat ◽  
A. Ziyari ◽  
M. Kazemzadeh ◽  
M. Shafiee
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Rotating Disc ◽  
Rotating Disc Contactor ◽  
Dimensional Simulation

Three Dimensional Simulation of the Effect of Windcatcher’s Inlet Shape

2019 ◽  
Author(s):  
Peter Abdo ◽  
Rahil Taghipour ◽  
B. P. Huynh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Environment ◽  
Natural Ventilation ◽  
Air Flow ◽  
Three Dimensional ◽  
Sectional Area ◽  
Cross Sectional ◽  
Dimensional Simulation ◽  
Convergent Inlet

Abstract Windcatcher has been used over centuries for providing natural ventilation using wind power, it is an effective passive method to provide healthy and comfortable indoor environment. The windcatcher’s function is based on the wind and on the stack effect resulting from temperature differences. Generally, it is difficult for wind to change its direction, and enter a room through usual openings, the windcatcher is designed to overcome such problems since they have vertical columns to help channel wind down to the inside of a building. The efficiency of a windcatcher is maximized by applying special forms of opening and exit. The openings depend on the windcatcher’s location and on its cross sectional area and shape such as square, rectangular, hexagonal or circular. In this study the effect of the inlet design is investigated to achieve better air flow and increase the efficiency of windcatchers. To achieve this, CFD (computational fluid dynamics) tool is used to simulate the air flow in a three dimensional room fitted with a windcatcher based on the different inlet designs. The divergent inlet has captured the highest air flow with a difference of approximately 3% compared to the uniform inlet and 5% difference compared to the bulging-convergent inlet.

Development of a zero-dimensional turbulence model for a spark ignition engine

2018 ◽  
Vol 20 (4) ◽  
pp. 441-451 ◽  
Author(s):  
Namho Kim ◽  
Insuk Ko ◽  
Kyoungdoug Min
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Length Scale ◽  
One Dimensional ◽  
Simulation Results ◽  
Dimensional Simulation

The necessity for the use of one-dimensional simulation is growing because cost and time required for hardware optimization and optimal calibration of engines based on experiment are increasing dramatically as engines are equipped with growing numbers of technologies. For one-dimensional simulation results to be more reliable, the accuracy and applicability of the combustion model of a one-dimensional simulation tool must be guaranteed. Because the combustion process in a spark ignition engine is driven by the turbulence, many of existing models focus on the prediction of mean turbulence intensity. Although many successes in the previous models can be found, the previous models contain a large number of adjustable constants or require information supplemented from three-dimensional computational fluid dynamics simulation results. For improved applicability of a model, the number of adjustable constants and inputs to the model must be kept as small as possible. Thus, in this study, a new zero-dimensional (0D) turbulence model was proposed that requires information on the basic characteristics of the engine geometry and has only one adjustable constant. The model was developed based on the energy cascade model with additional consideration of following aspects: loss of kinetic energy during the intake stroke, the effect of piston motion during the compression and the expansion stroke, modifications to correlations for integral length scale, geometric length scale, and production rate of turbulent kinetic energy. An adjustable constant to consider engine design which determines tumble strength was also introduced. The comparison of the simulation results with those of three-dimensional computational fluid dynamics confirmed that the developed model can predict the mean turbulence intensity without case-dependent adjustment of the model constant.

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