Effect of Blade Numbers on Pressure Drop of Axial Cyclone Separators by CFD

2011 ◽  
Vol 55-57 ◽  
pp. 343-347 ◽  
Author(s):  
Yi Gang Luan ◽  
Hai Ou Sun
Keyword(s):  
Pressure Drop ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Three Dimensional Model ◽  
Navier Stokes Equations ◽  
Pressure Drops ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Resistance Performance

In this article, computational fluid dynamics(CFD) method is used to predict the effect of blade numbers on the pressure drop of axial cyclone separators. A three-dimensional model is built to acquire the resistance of axial cyclone separators with different blade numbers. The flow field inside cyclone separators is calculated using 3D Reynolds-averaged Navier-Stokes equations. And turbulence model is used to simulate the Reynold stress. Also pressure drop of cyclone separators with different blade numbers is expressed as a function of different inlet velocities. At the same inlet velocity with increasing the blade numbers, pressure drops of cyclones reduce greatly. And changing the blade number of cyclone separator is an effective method to improve its resistance performance.

A 3D Unsteady Flow Analysis in a Doubly Constricted Tube

2000 ◽  
Author(s):  
B. V. Rathish Kumar ◽  
T. Yamaguchi ◽  
H. Liu ◽  
R. Himeno
Keyword(s):  
Pressure Drop ◽  
Unsteady Flow ◽  
Stokes Equations ◽  
Vortex Formation ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
In Series ◽  
3D Unsteady Flow

Abstract Unsteady flow dynamics in a doubly constricted vessel is analyzed by using a time accurate Finite Volume solution of three dimensional incompressible Navier-Stokes equations. Computational experiments are carried out for various values of Reynolds number in order to assess the criticality of multiple mild constrictions in series and also to bring out the subtle 3D features like vortex formation. Studies reveal that pressure drop across a series of mild constrictions can get physiologically critical. Further this pressure drop is found to be sensitive to the spacing between the constrictions and also to the oscillatory nature of the inflow profile.

Numerical Investigation of the Effect of Balancing-Hole on the Axial Force of a Partial Emission Pump

2014 ◽  
Author(s):  
Zhang Lisheng ◽  
Jiang Jin ◽  
Xiao Zhihuai ◽  
Li Yanhui
Keyword(s):  
Axial Force ◽  
Stokes Equations ◽  
Dominant Role ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Design Parameters ◽  
Navier Stokes Equations ◽  
Computational Fluid Dynamics Cfd ◽  
The Cost

In this paper numerical simulations were conducted to analyze the effects of design parameters and distribution of balancing-hole on the axial-force of a partial emission pump. The studied pump is a single stage pump with a Barske style impeller. Based on the original impeller, we designed 7 pumps with different balancing-hole diameters and the partial emission pump equipped with different impellers were simulated employing the commercial computational fluid dynamics (CFD) software Fluent 12.1 to solve the Navier-Stokes equations for three-dimensional steady flow. A sensitivity analysis of the numerical model was performed with the purpose of balancing the contradiction of numerical accuracy and the cost of calculation. The results showed that, with increasing of the capacity, the axial force varies little. The diameter of the inner balancing-hole plays a dominant role of reducing axial-force of partial emission pump, the axial-force decreases with increasing of inner balancing-hole diameter on the whole range of operation, the axial-force of impeller without inner balancing-hole is approximately 3 times larger than that of impeller with inner balancing-hole. While the diameter of outer balancing-hole has a reverse effects compared with that of inner balancing-hole. With increasing of outer balancing-hole, the axial force increases accordingly.

scholarly journals Hydrodynamic Effects Produced by Submerged Breakwaters in a Coastal Area with a Curvilinear Shoreline

2019 ◽  
Vol 7 (10) ◽  
pp. 337 ◽  
Author(s):  
Francesco Gallerano ◽  
Giovanni Cannata ◽  
Federica Palleschi
Keyword(s):  
Coastal Area ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Integral Form ◽  
Navier Stokes ◽  
Hydrodynamic Effect ◽  
Riemann Solver ◽  
Three Dimensional Model ◽  
Navier Stokes Equations

A three-dimensional numerical study of the hydrodynamic effect produced by a system of submerged breakwaters in a coastal area with a curvilinear shoreline is proposed. The three-dimensional model is based on an integral contravariant formulation of the Navier-Stokes equations in a time-dependent curvilinear coordinate system. The integral form of the contravariant Navier-Stokes equations is numerically integrated by a finite-volume shock-capturing scheme which uses Monotonic Upwind Scheme for Conservation Laws Total Variation Diminishing (MUSCL-TVD) reconstructions and an Harten Lax van Leer Riemann solver (HLL Riemann solver). The numerical model is used to verify whether the presence of a submerged coastal defence structure, in the coastal area with a curvilinear shoreline, is able to modify the wave induced circulation pattern and the hydrodynamic conditions from erosive to accretive.

Design of a Fractal Tree-Like Microchannel Net Heat Sink for Microelectronic Cooling

2006 ◽  
Author(s):  
F. J. Hong ◽  
P. Cheng ◽  
H. Ge ◽  
Teck Joo Goh
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Electronic Cooling ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Numerical Result ◽  
Parallel Microchannels

In this paper, a numerical simulation is carried to study pressure drop and heat transfer in a fractal tree-like microchannel net heat sink of 10mm×12.5mm×0.5mm in dimensions. The numerical result is obtained by solving three-dimensional Navier-Stokes equations and energy equation, taking into consideration conjugate heat transfer in the microchannel walls. A comparison of fractal tree-like microchannel net heat sink with 6 branch levels to parallel microchannels heat sink, with respect to the pressure drop, thermal resistance and temperature uniformity, was also performed under the condition of the same heat sink dimensions. The results indicates that for a mass flow rate of water less than 0.00175kg/s, the fractal tree-like microchannel is much better than parallel channel heat sink with respect to all of three aspects. Therefore, the fractal tree-like microchannels net heat sink using water as the coolant is promising to be used in the future electronic cooling industry.

Spent Flow Effects of Multiple Micro-Jet Impingement Cooling Models

2015 ◽  
Author(s):  
Afzal Husain ◽  
Nasser A. Al-Azri ◽  
Abdus Samad ◽  
Sun-Min Kim ◽  
Kwang-Yong Kim
Keyword(s):  
Pressure Drop ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Jet Impingement ◽  
Navier Stokes ◽  
Maximum Temperature ◽  
Design Parameters ◽  
Comparative Performance ◽  
Navier Stokes Equations

The current study investigated comparative performance of wall-confined and unconfined multiple micro-jet impingement heat sink models for electronic cooling applications. The pressure-drop and thermal characteristics were determined for steady incompressible and laminar flow by solving three-dimensional Navier–Stokes equations. Several parallel and staggered micro-jet configurations consisting of a maximum of 16 jet impingements were tested. The effectiveness of various micro-jet configurations, i.e., inline 2×2, 3×3 and 4×4 jets, and staggered 5-jet and 13-jet arrays with nozzle diameters 50, 76, and 100 μm, were analyzed at various flow rates for the maximum temperature-rise, pressure-drop and heat transfer coefficient characteristics. Two design parameters, the ratio of jet diameter to height of the channel and jet distribution, were chosen for comparative performance analysis.

The effect of temperature on the fluid flow dynamics in technical systems with jets

2016 ◽  
Vol 11 (1) ◽  
pp. 1-9 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh. Nasibullaeva
Keyword(s):  
Pressure Drop ◽  
High Pressures ◽  
Microelectromechanical Systems ◽  
Stokes Equations ◽  
Significant Loss ◽  
Effect Of Temperature ◽  
Navier Stokes ◽  
Axially Symmetric ◽  
Navier Stokes Equations ◽  
Pressure Drops

In this paper the steady flow of technical fluid induced pressure drop in the channel with a cylindrical jet for the entire working temperature range have been studied. The Navier–Stokes equations are solved numerically in axially symmetric geometry by the finite element method. The temperature dependence of the material parameters of a number of liquids, most commonly used in technical devices have been obtained. A model of a cylindrical jet was built in the form of a computing element of the stand, which takes into account the pressure drop, the radius of passage opening jet and the liquid temperature for the areas with low and high pressure drops. This model allows without significant loss of accuracy replace the complete numerical simulation, requires more computational resources, by simple analytical formulas admitting modeling in computational stand in real time. The model can be used in various technical applications of microelectromechanical systems (at low pressure drops) to the fuel metering elements (at high pressures drops).

scholarly journals Three-Dimensional Separations in Axial Compressors

2005 ◽  
Vol 127 (2) ◽  
pp. 331-339 ◽  
Author(s):  
Semiu A. Gbadebo ◽  
Nicholas A. Cumpsty ◽  
Tom P. Hynes
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Tip Clearance ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Compressor Blades ◽  
Navier Stokes Equations ◽  
Axial Compressors ◽  
Computational Fluid Dynamics Cfd ◽  
Limiting Streamlines

Flow separations in the corner regions of blade passages are common. The separations are three dimensional and have quite different properties from the two-dimensional separations that are considered in elementary courses of fluid mechanics. In particular, the consequences for the flow may be less severe than the two-dimensional separation. This paper describes the nature of three-dimensional (3D) separation and addresses the way in which topological rules, based on a linear treatment of the Navier-Stokes equations, can predict properties of the limiting streamlines, including the singularities which form. The paper shows measurements of the flow field in a linear cascade of compressor blades and compares these to the results of 3D computational fluid dynamics (CFD). For corners without tip clearance, the presence of three-dimensional separation appears to be universal, and the challenge for the designer is to limit the loss and blockage produced. The CFD appears capable of predicting this.

scholarly journals Numerical Research on Flow Characteristics around a Hydraulic Turbine Runner at Small Opening of Cylindrical Valve

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Zhenwei Mo ◽  
Juliang Xiao ◽  
Gang Wang
Keyword(s):  
Flow Velocity ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Hydraulic Turbine ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Small Opening ◽  
Turbine Runner ◽  
Computational Fluid Dynamics Cfd

We use the continuity equation and the Reynolds averaged Navier-Stokes equations to study the flow-pattern characteristics around a turbine runner for the small-opening cylindrical valve of a hydraulic turbine. For closure, we adopt the renormalization-groupk-εtwo-equation turbulence model and use the computational fluid dynamics (CFD) software FLUENT to numerically simulate the three-dimensional unsteady turbulent flow through the entire passage of the hydraulic turbine. The results show that a low-pressure zone develops around the runner blades when the cylindrical valve is closed in a small opening; cavitation occurs at the blades, and a vortex appears at the outlet of the runner. As the cylindrical valve is gradually closed, the flow velocity over the runner area increases, and the pressure gradient becomes more significant as the discharge decreases. In addition, the fluid flow velocity is relatively high between the lower end of the cylindrical valve and the base, so that a high-velocity jet is easily induced. The calculation and analysis provide a theoretical basis for improving the performance of cylindrical-valve operating systems.

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