Computational Fluid Dynamics Techniques for Flows in Lapple Cyclone Separator

2005 ◽  
Vol 498-499 ◽  
pp. 179-185
Author(s):  
A.F. Lacerda ◽  
Luiz Gustavo Martins Vieira ◽  
A.M. Nascimento ◽  
S.D. Nascimento ◽  
João Jorge Ribeiro Damasceno ◽  
...  

A two-dimensional fluidynamics model for turbulent flow of gas in cyclones is used to evaluate the importance of the anisotropic of the Reynolds stress components. This study presents consisted in to simulate through computational fluid dynamics (CFD) package the operation of the Lapple cyclone. Yields of velocity obtained starting from a model anisotropic of the Reynolds stress are compared with experimental data of the literature, as form of validating the results obtained through the use of the Computational fluid dynamics (Fluent). The experimental data of the axial and swirl velocities validate numeric results obtained by the model.

2021 ◽  
Vol 2059 (1) ◽  
pp. 012003
Author(s):  
A Burmistrov ◽  
A Raykov ◽  
S Salikeev ◽  
E Kapustin

Abstract Numerical mathematical models of non-contact oil free scroll, Roots and screw vacuum pumps are developed. Modelling was carried out with the help of software CFD ANSYS-CFX and program TwinMesh for dynamic meshing. Pumping characteristics of non-contact pumps in viscous flow with the help of SST-turbulence model were calculated for varying rotors profiles, clearances, and rotating speeds. Comparison with experimental data verified adequacy of developed CFD models.


Author(s):  
Nazia Binte Munir ◽  
Kyoungsoo Lee ◽  
Ziaul Huque ◽  
Raghava R. Kommalapati

The main purpose of the paper is to use Computational Fluid Dynamics (CFD) in 3-D analysis of aerodynamic forces of a Horizontal Axis Wind Turbine (HAWT) blade and compare the 3-D results with the 2-D experimental results. The National Renewable Energy Laboratory (NREL) Phase VI wind blade profile is used as a model for the analysis. The results are compared with the experimental data obtained by NREL at NASA Ames Research Center for the NREL Phase VI wind turbine blade. The aerodynamic forces are evaluated using 3-D Computational Fluid Dynamics (CFD) simulation. The commercial ANSYS CFX and parameterized 3-D CAD model of NREL Phase VI are used for the analysis. The Shear Stress Transport (SST) Gamma-Theta turbulence model and 0-degree yaw angle condition are adopted for CFD analysis. For the case study seven varying wind speeds (5 m/s, 7 m/s, 10 m/s, 13 m/s, 15 m/s, 20 m/s, 25 m/s) with constant blade rotational speed (72 rpm) are considered. To evaluate the 3-D aerodynamic effect sectional pressure coefficient (Cp) and integrated forces about primary axis such as normal, tangential, thrust and torque are evaluated for each of the seven wind speed cases and compared with the NREL experimental values. The numerical difference of values on wind blade surface between this study and 3-D results of NREL wind tunnel test are found negligible. The paper represents an important comparison between the 3-D lift & drag coefficient with the NREL 2-D experimental data. The results shows that though the current study is in good agreement with NREL 3-D experimental values there is large deviation between the NREL 2-D experimental data and current 3-D study which suggests that in case of 3-D analysis of aerodynamic force of blade surface it is better to use NREL 3-D values instead of 2-D experimental values.


Author(s):  
G Ingram ◽  
D Gregory-Smith ◽  
N Harvey

Non-axisymmetric profiled endwalls have been shown to reduce losses and secondary flow both in cascades and in rig tests. This paper presents experimental results which quantify the benefits of loss reduction in the cascade with particular attention to accuracy. The paper compares the benefits achieved in experiment to the results predicted by computational fluid dynamics (CFD). The results show that both the experiment and CFD give significant reductions in secondary flow. A reduction of 31 per cent in secondary loss has been measured for the best case, but the CFD gives only a small reduction in loss. Previous studies on the planar endwall have shown significant areas of transitional flow, so the surface flow has been studied with the aid of surface-mounted hot films. It was concluded that the loss reductions were not due to changes in regions of laminar and turbulent flow.


2013 ◽  
Vol 20 (05) ◽  
pp. 1350043 ◽  
Author(s):  
YUNCAI ZHAO ◽  
LEI HAN

A two-dimensional computational fluid dynamics (CFD) model was developed to study the load-bearing capacity of asymmetric texture under the state of fluid lubrication. The effects of asymmetric parameter H and the Reynolds number Re on hydrodynamic load-bearing capacity of the oil film were discussed. It was found that a decrease in asymmetric parameter H may significantly improve the load-bearing capacity, but an increase in Reynolds number Re may reduce this effect. For example, with a Re at 20, the load-bearing capacity increases by 73.44% with the H varying from 4 to 0.2. However, with a Re at 160, it has only an increase of 4.68% at the same conditions. In addition, the numerical results also showed that the load-bearing capacity will increase with the increase of Re in certain texture.


2005 ◽  
Vol 33 (3) ◽  
pp. 195-207 ◽  
Author(s):  
Z. Husain ◽  
M. Z. Abdullah ◽  
T. C. Yap

The two-dimensional analysis, using computational fluid dynamics (CFD), of tandem/staggered arranged airfoils of the canard and wing of an Eagle 150 aircraft and also the aerodynamic tests conducted in an open-circuit wind tunnel are presented in the paper. The wind tunnel tests were carried out at a speed of 38m/s in a test section of size 300 mm (width), 300 mm (height) and 600 mm (length), at Reynolds number 2.25 × 105. The tests were carried out with tandem and staggered placement of the airfoils in order to determine the optimum position of the wing with respect to the canard and also to determine the lift coefficient at various angles of attack. The CFD code FLUENT 5 was used to investigate the aerodynamic performance of a two-dimensional model to validate the wind tunnel results. The flow interaction was studied in the tandem and staggered arrangements in the wind tunnel as well as by the computational method. The k-ε turbulence model gave exceptionally good results.


2013 ◽  
Vol 694-697 ◽  
pp. 307-311
Author(s):  
Jia Wei Ren ◽  
Qin Yu Jiang ◽  
Zhen Wang

Computational fluid dynamics (CFD) software was used to simulate the internal flow field of an example muffler, and compared the results with the experimental data, verifying the reliability of the simulation algorithm. On this basis, changed the example muffler structure, researched the pressure loss of muffler which was influenced by the insert duct, the position of the baffle and the inlet air velocity. The corresponding regularities have been obtained with the results of computations, which provide a basis for the design of the muffler.


2010 ◽  
Vol 660-661 ◽  
pp. 158-163
Author(s):  
M.Ramirez Valverde ◽  
José Renato Coury ◽  
José Antônio Silveira Gonçalves

In recent years, many computational fluid dynamics (CFD) studies have appeared attempting to predict cyclone pressure drop and collection efficiency. While these studies have been able to predict pressure drop well, they have been only moderately successful in predicting collection efficiency. Part of the reason for this failure has been attributed to the relatively simple wall boundary conditions implemented in the commercially available CFD software, which are not capable of accurately describing the complex particle-wall interaction present in a cyclone. According, researches have proposed a number of different boundary conditions in order to improve the model performance. This work implemented the critical velocity boundary condition through a user defined function (UDF) in the Fluent software and compared its predictions both with experimental data and with the predictions obtained when using Fluent’s built-in boundary conditions. Experimental data was obtained from eight laboratory scale cyclones with varying geometric ratios. The CFD simulations were made using the software Fluent 6.3.26.


Author(s):  
Alexandre T. P. Alho

In response to the need for better designs in less time and at low costs, computational fluid dynamics (CFD) is becoming an integral part of the vessel’s design process. Recent studies have shown that CFD techniques can be used with relative success for the problem of ship resistance prediction. This paper reports on the simulation of the flow around a typical catamaran hull by means of CFD computations. The numerical model used in the simulations was developed in full scale with the experimental model in order to eliminate any source of scale effects. The paper presents a discussion on grid configuration and an analysis of the performance of the numerical model in describing the characteristics of the in-between hulls flow. The results obtained were validated against experimental data.


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