Influence of Guide Vanes' Angle on Flow Fields of Cylinder Cage Powder Classifier

2012 ◽  
Vol 263-266 ◽  
pp. 843-846 ◽  
Author(s):  
Da Zhi Jiang ◽  
Jing Han

To research guide vanes' influences on flow fields of cylinder cage powder classifier at different angles, a study of guide vanes under 3 different angles is therefore undertaken examining air flow behavior. The investigation of these flow field characteristics made use of the computational fluid dynamics (CFD) to simulate the air flow in the classifier. The results indicate that smaller angles of guide vanes can increase velocity but damage the stability of flow fields, and that those larger angles will reduce the velocity.

2005 ◽  
Vol os-14 (1) ◽  
pp. 1558925005os-14
Author(s):  
Holly M. Krutka ◽  
Robert L. Shambaugh ◽  
Dimitrios V. Papavassiliou

This paper is an investigation of the flow fields generated by dual rectangular jets. Specifically, the jets examined are the same as the common slot dies used in the industrial melt blowing process. In this process, a molten polymer is attenuated by air discharging from dual jets. The velocity and turbulence of these flow fields determine the rate and quality of polymer fiber production. The flow field characteristics can be simulated quickly and efficiently using computational fluid dynamics (CFD). These CFD simulations require the use of an appropriate length scale to describe the flow field. This paper describes how these CFD simulations can be used to compare the flow fields generated by different jet geometries.


2013 ◽  
Vol 368-370 ◽  
pp. 619-623
Author(s):  
Zhen Liu ◽  
Xiao Ling Wang ◽  
Ai Li Zhang

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.


2014 ◽  
Vol 1030-1032 ◽  
pp. 819-822
Author(s):  
Xiu Guo Zhao ◽  
Xin Xi Xu ◽  
Chen Su ◽  
Fu Niu ◽  
Shu Lin Tan ◽  
...  

The computational fluid dynamics (CFD) is used to design the position of the inlet and outlet of the air conditioning and analyzing the air flow field and temperature distribution inside the operating room .The result showed the purification air conditioning of the mobile operating room can make air flow along only single direction with effectively avoiding the contamination gathering in the surgical area. It also can improve air cleanness of surgical area and fight against the infection of the patient wound. In the surgical area, the temperature is distributed around 23°C with perfect temperature distribution without obviously temperature gradient.


2017 ◽  
Vol 77 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Haoming Yang ◽  
David Z. Zhu ◽  
Yanchen Liu

Abstract Determining the proper installation location of flow meters is important for accurate measurement of discharge in sewer systems. In this study, flow field and flow regimes in two types of manholes under surcharged flow were investigated using a commercial computational fluid dynamics (CFD) code. The error in measuring the flow discharge using a Doppler flow meter (based on the velocity in a Doppler beam) was then estimated. The values of the corrective coefficient were obtained for the Doppler flow meter at different locations under various conditions. Suggestions for selecting installation positions are provided.


Author(s):  
Hasham H. Chougule ◽  
Alexander Mirzamoghadam

The objective of this study is to develop a Computational Fluid Dynamics (CFD) based methodology for analyzing and predicting leakage of worn or rub-intended labyrinth seals during operation. The simulations include intended tooth axial offset and numerical modeling of the flow field. The purpose is to predict total leakage through the seal when an axial tooth offset is provided after the intended/unintended rub. Results indicate that as expected, the leakage for the in-line worn land case (i.e. tooth under rub) is higher compared to unworn. Furthermore, the intended rotor/teeth forward axial offset/shift with respect to the rubbed land reduces the seal leakage. The overall leakage of a rubbed seal with axial tooth offset is observed to be considerably reduced, and it can become even less than a small clearance seal designed not to rub. The reduced leakage during steady state is due to a targeted smaller running gap because of tooth offset under the intended/worn land groove shape, higher blockages, higher turbulence and flow deflection as compared to worn seal model without axial tooth offset.


2015 ◽  
Author(s):  
Brent S. Paul

The successful integration of aviation capabilities aboard ships is a complex endeavor that must balance ship design with the flight envelope of the helicopter. This can be particularly important when considering air wakes and other flow around the superstructure as it impacts the flight deck. This flow can generate unsteady structures that may interfere with safe helicopter operations. Computational fluid dynamics (CFD) is commonly used to characterize the flow field and assess potential impacts to the flight envelope, which can be used to help define an operating envelope for helicopter operations.


Author(s):  
Melih Demir ◽  
Govert de With ◽  
Arne E. Holdo̸

At present a large number of fluid dynamics applications are found in aerospace, civil and automotive engineering, as well in medical related fields. In many applications the flow field is turbulent and the computational modelling of such flows remains a difficult task. To resolve all turbulent flow phenomena for flow problems where turbulence is of key interest is a priori not feasible in a Computational Fluid Dynamics (CFD) investigation with a conventional mesh. The use of a Dynamic Grid Adaptation (DGA) algorithm in a turbulent unsteady flow field is an appealing technique which can reduce the computational costs of a CFD investigation. A refinement of the numerical domain with a DGA algorithm requires reliable criteria for mesh refinement which reflect the complex flow processes. At present not much work has been done to obtain reliable refinement criteria for turbulent unsteady flow. The purpose of the work is to implement a new refinement technique for the boundary layer in the vicinity of the wall. It is aimed to model the flow around an airfoil with a LES turbulence model and a new DGA algorithm. In addition to that several simulations have been carried out for parametric studies. In these studies the incompressible solver in REACFLOW has been used. This Computational Fluid Dynamics (CFD) code REACFLOW was developed in collaboration with the joint Research Centre (JRC) in Italy. The following aims are aspired: • A new mesh refinement criteria method suitable for boundary layers; • To carry out LES simulations to establish the performance of the refinement criteria. The new criteria which are created in this work are for the near wall region. This criteria uses the wall shear stresses for the refinement technique. For the main flow stream the refinement criteria proposed by de With et al [6] will be used.


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