scholarly journals Hydrodynamics of a reactor with updated structure of frame mixing device

2021 ◽  
pp. 7-14
Author(s):  
V.O. Zazymko ◽  
M.F. Kalinina ◽  
V.Y. Shibetsky ◽  
O.M. Nedbailo
Keyword(s):  
Computer Simulation ◽  
Fluid Flow ◽  
Comparative Analysis ◽  
Fluid Flows ◽  
3D Models ◽  
Mixing Efficiency ◽  
Mixing Process ◽  
Element Analysis ◽  
Standard Design ◽  
Hydrodynamic Situation

This article is devoted to computer simulation of the hydrodynamic situation in a reactor with a standard design and an upgraded design of a frame stirrer. A comparative analysis of the hydrodynamics of fluid flows occurring in the volume due to the use of classical and modernized design was performed. An upgraded design of a frame stirrer for homogenizing the medium in a reactor has been proposed. The aim of this work was to study the influence of the geometry of the stirrer blades and their location in space on the speed and direction of flows in the reactor. The basis for the new design of the mixing device was the standard design of the frame mixer with two horizontal jumpers. Installation of additional blades and their placement at a certain angle to the vertical and horizontal planes and relative to each other was considered as one of the methods of improving the design. For this work, the study was conducted in the universal software system of finite element analysis ANSYS. Computer simulation is used to analyze complex systems and processes based on a computer model. The simulation was performed to analyze the influence of the geometry of the mixing device on the speed and direction of fluid flow in the apparatus. To conduct the study, 3D-models of two different types of geometry of the mixing device were built, physicomechanical parameters of the environment in the reactor were set and on the basis of these data the mixing process in the apparatus was modeled. In this work, the influence of plate geometry and their location in space on hydrodynamics is investigated. The basis of the proposed design of the mixing device is the task of intensifying the mixing process by increasing the mixing efficiency along the height of the apparatus. A comparative analysis of the direction of fluid flow, its velocity and temperature change using a standard and upgraded design of the mixing device was performed. It was found that when installing additional plates that are located at an angle to the horizontal and vertical planes in the reactor there are additional axial and radial fluid flows, which improves homogeneity and increases the intensity of mixing.

Lattice-BGK Methods for Simulating Incompressible Fluid Flows

1997 ◽  
Vol 08 (04) ◽  
pp. 793-803 ◽  
Author(s):  
Yu Chen ◽  
Hirotada Ohashi
Keyword(s):  
Fluid Flow ◽  
Incompressible Fluid ◽  
Poisson Equation ◽  
General Model ◽  
Incompressible Flows ◽  
Fluid Flows ◽  
Incompressible Limit ◽  
Numerical Example ◽  
Incompressible Fluid Flows

The lattice-Bhatnagar-Gross-Krook (BGK) method has been used to simulate fluid flow in the nearly incompressible limit. But for the completely incompressible flows, two special approaches should be applied to the general model, for the steady and unsteady cases, respectively. Introduced by Zou et al.,1 the method for steady incompressible flows will be described briefly in this paper. For the unsteady case, we will show, using a simple numerical example, the need to solve a Poisson equation for pressure.

Flow Features Analysis of Throttle Notches of Proportional Direct Valve

2011 ◽  
Vol 189-193 ◽  
pp. 2285-2288
Author(s):  
Wen Hua Jia ◽  
Chen Bo Yin ◽  
Guo Jin Jiang
Keyword(s):  
Fluid Flow ◽  
Dynamic Behavior ◽  
Flow Rate ◽  
Discharge Coefficient ◽  
3D Models ◽  
Operating Conditions ◽  
Flow Models ◽  
Flow Features ◽  
Rate Discharge ◽  
Spool Valve

Flow features, specially, flow rate, discharge coefficient and efflux angle under different operating conditions are numerically simulated, and the effects of shapes and the number of notches on them are analyzed. To simulate flow features, 3D models are developed as commercially available fluid flow models. Most construction machineries in different conditions require different actions. Thus, in order to be capable of different actions and exhibit good dynamic behavior, flow features should be achieved in designing an optimized proportional directional spool valve.

Component Low Cycle Fatigue Behavior Based on Standard Calculation Procedure and Non-Linear FEA

2017 ◽  
Author(s):  
Jürgen Rudolph ◽  
Adrian Willuweit ◽  
Steffen Bergholz ◽  
Christian Philippek ◽  
Jevgenij Kobzarev
Keyword(s):  
Power Plants ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hybrid Approach ◽  
Combined Cycle ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
Constitutive Material Model ◽  
Standard Design ◽  
Creep Fatigue

Components of conventional power plants are subject to potential damage mechanisms such as creep, fatigue and their combination. These mechanisms have to be considered in the mechanical design process. Against this general background — as an example — the paper focusses on the low cycle fatigue behavior of a main steam shut off valve. The first design check based on standard design rules and linear Finite Element Analysis (FEA) identifies fatigue sensitive locations and potentially high fatigue usage. This will often occur in the context of flexible operational modes of combined cycle power plants which are a characteristic of the current demands of energy supply. In such a case a margin analysis constitutes a logical second step. It may comprise the identification of a more realistic description of the real operational loads and load-time histories and a refinement of the (creep-) fatigue assessment methods. This constitutes the basis of an advanced component design and assessment. In this work, nonlinear FEA is applied based on a nonlinear kinematic constitutive material model, in order to simulate the thermo-mechanical behavior of the high-Cr steel component mentioned above. The required material parameters are identified based on data of the accessible reference literature and data from an own test series. The accompanying testing campaign was successfully concluded by a series of uniaxial thermo-mechanical fatigue (TMF) tests simulating the most critical load case of the component. This detailed and hybrid approach proved to be appropriate for ensuring the required lifetime period of the component.

A Suction Device Using Air Under Pressure

1956 ◽  
Vol 23 (2) ◽  
pp. 269-272
Author(s):  
L. F. Welanetz
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Fluid Flows ◽  
Central Hole ◽  
Fluid Flow Rate ◽  
Circular Plates ◽  
Suction Device ◽  
Holding Power ◽  
Plate Separation

Abstract An analysis is made of the suction holding power of a device in which a fluid flows radially outward from a central hole between two parallel circular plates. The holding power and the fluid flow rate are determined as functions of the plate separation. The effect of changing the proportions of the device is investigated. Experiments were made to check the analysis.

scholarly journals High Mixing Efficiency by Modulating Inlet Frequency of Viscoelastic Fluid in Simplified Pore Structure

Processes ◽  
2018 ◽  
Vol 6 (11) ◽  
pp. 210 ◽  
Author(s):  
Meng Zhang ◽  
Yunfeng Cui ◽  
Weihua Cai ◽  
Zhengwei Wu ◽  
Yongyao Li ◽  
...  
Keyword(s):  
Viscoelastic Fluid ◽  
Essential Role ◽  
Fluid Flows ◽  
Fluid Mixing ◽  
Modulation Method ◽  
Mixing Efficiency ◽  
Microscale Flow ◽  
Pressure Modulation ◽  
Active Mixing ◽  
Junction Structure

Fluid mixing plays an essential role in microscale flow systems. Here, we propose an active mixing approach which enhances the mixing of viscoelastic fluid flow in a simplified pore T-junction structure. Mixing is actively controlled by modulating the driving pressure with a sinusoidal signal at the two inlets of the T-junction. The mixing effect is numerically investigated for both Newtonian and viscoelastic fluid flows under different pressure modulation conditions. The result shows that a degree of mixing as high as 0.9 is achieved in viscoelastic fluid flows through the T-junction mixer when the phase difference between the modulated pressures at the two inlets is 180°. This modulation method can also be used in other fluid mixing devices.

scholarly journals Numerical Investigation on Fluid Flow in a 90-Degree Curved Pipe with Large Curvature Ratio

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Yan Wang ◽  
Quanlin Dong ◽  
Pengfei Wang
Keyword(s):  
Fluid Flow ◽  
Internal Flow ◽  
Fluid Flows ◽  
Detached Eddy Simulation ◽  
Number Range ◽  
Curvature Ratio ◽  
Large Curvature ◽  
Curved Pipe ◽  
Eddy Simulation ◽  
Curved Pipes

In order to understand the mechanism of fluid flows in curved pipes, a large number of theoretical and experimental researches have been performed. As a critical parameter of curved pipe, the curvature ratioδhas received much attention, but most of the values ofδare very small (δ<0.1) or relatively small (δ≤0.5). As a preliminary study and simulation this research studied the fluid flow in a 90-degree curved pipe of large curvature ratio. The Detached Eddy Simulation (DES) turbulence model was employed to investigate the fluid flows at the Reynolds number range from 5000 to 20000. After validation of the numerical strategy, the pressure and velocity distribution, pressure drop, fluid flow, and secondary flow along the curved pipe were illustrated. The results show that the fluid flow in a curved pipe with large curvature ratio seems to be unlike that in a curved pipe with small curvature ratio. Large curvature ratio makes the internal flow more complicated; thus, the flow patterns, the separation region, and the oscillatory flow are different.

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