scholarly journals Proximity Effects on Characteristics of Flow around Three Inline Square Cylinders

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Waqas Sarwar Abbasi ◽  
Shams Ul Islam ◽  
Hamid Rahman
Keyword(s):  
Fluid Flow ◽  
Bluff Body ◽  
Flow Characteristics ◽  
Proximity Effects ◽  
Flow Parameters ◽  
Square Cylinders ◽  
Fluid Flow Characteristics ◽  
Bluff Body Flow ◽  
Boltzmann Method ◽  
Gap Spacing

This work presents the numerical investigations performed to study the proximity effects on fluid flow characteristics around three inline square cylinders using the lattice Boltzmann method. For this purpose the gap spacing (g) is systematically varied in the range 0.5 to 16 diameters of cylinder by keeping Reynolds number fixed at 200. Five different flow patterns are observed at different values of spacing: bluff body flow, gap trapped flow, irregular flow, alternate shedding, and modulated shedding. These patterns have a significant effect on flow induced forces and vortex shedding frequency. The spacing value g = 2 is found to be critical due to sudden changes in fluid flow characteristics. The flow parameters of first cylinder are found to be closer to single cylinder values but for middle and third cylinder the differences confirm the wake interference effect even at large values of spacing.

Fluid Flow Characteristics of a Confined Slot Jet Without or With a Target Surface

2005 ◽  
Author(s):  
L. K. Liu ◽  
C. J. Fang ◽  
M. C. Wu ◽  
C. Y. Lee ◽  
Y. H. Hung
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Fluid Velocity ◽  
Flow Characteristics ◽  
Target Surface ◽  
Streamwise Velocity ◽  
Separation Distance ◽  
Experimental Investigations ◽  
Flow Parameters ◽  
Fluid Flow Characteristics

A series of experimental investigations with a stringent measurement method on the fluid flow characteristics of slot jet without or with a target surface have been successfully conducted. From all the fluid velocity data measured in the present study, the experimental conditions have been verified to be spanwise-symmetrically maintained and the results have been achieved in a spanwise-symmetric form. Three types of jet configuration without or with target surface are investigated: (A) Confined Slot Jet without Target Surfaces – the fluid flow parameters studied in the present investigation is the jet Reynolds number (ReD). Its ranges are ReD=506-1517. (B) Confined Slot Jet with Smooth Surfaces – the fluid flow parameters studied in the present investigation include the ratio of jet separation distance (H) to nozzle width (W) and the jet Reynolds number (ReD). The ranges of the relevant parameters are H/W=2–10 and ReD=504–1526. (C) Confined Slot Jet with Extended Surfaces – the fluid flow parameters studied include the ratio of jet separation distance (H) to nozzle width (W), the Reynolds number (ReD) and the ratio of extended surface height (Hes) to nozzle width (W). Their ranges are H/W=3–10, Hes/W=0.74-3.40 and ReD=501–1547. The flow characteristics such as the local mean streamwise velocity distribution, mean streamwise velocity decay along jet centerline, local jet turbulence intensity distribution, and turbulence intensities along jet centerline have been presented and discussed in the study.

Wake Interaction Using Lattice Boltzmann Method

2018 ◽  
pp. 223-261
Author(s):  
K. Karthik Selva Kumar ◽  
L. A. Kumaraswamidhas
Keyword(s):  
Fluid Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Computational Simulation ◽  
Fluid Structure Interaction ◽  
Flow Characteristics ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Flow Characteristics ◽  
Boltzmann Method

In this chapter, a brief discussion about the application of lattice Boltzmann method on complex flow characteristics over circular structures is presented. A two-dimensional computational simulation is performed to study the fluid flow characteristics by employing the lattice Boltzmann method (LBM) with respect to Bhatnagar-Gross-Krook (BGK) collision model to simulate the interaction of fluid flow over the circular cylinders at different spacing conditions. From the results, it is observed that there is no significant interaction between the wakes for the transverse spacing's ratio higher than six times the cylinder diameter. For smaller transverse spacing ratios, the fluid flow regimes were recognized with presence of vortices. Apart from that, the drag coefficient signals are revealed as chaotic, quasi-periodic, and synchronized regimes, which were observed from the results of vortex shedding frequencies and fluid structure interaction frequencies. The strength of the latter frequency depends on spacing between the cylinders; in addition, the frequency observed from the fluid structure interaction is also associated with respect to the change in narrow and wide wakes behind the surface of the cylinder. Further, the St and mean Cd are observed to be increasing with respect to decrease in the transverse spacing ratio.

scholarly journals Effect of magnetic field on fluid flow characteristics and augmentation of heat transfer in a heat exchanger

2021 ◽  
Author(s):  
Mohammed Almeshaal ◽  
◽  
Sujoy Saha ◽  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Control Volume ◽  
Flow Characteristics ◽  
Research Area ◽  
Flow Parameters ◽  
Fluid Flow Characteristics ◽  
The Impact

The study of fluid flow, subjected to an external magnetic field has become an attractive and demanding research area because of its huge applications. In this work, water base magnetic nanofluid dynamics, taking into account the Magnetohydrodynamics (MHD) phenomenon has been explicitly investigated. In this study, governing equations are coupled with Magnetohydrodynamics (MHD) and are solved with the help of a finite volume procedure based on a control volume approach. The numerical outcomes of the simulation are depicted and discussed sequentially in terms of different contour and flow parameters. The impact of Magnetic number arising from Magneto Hydro Dynamics (MHD) ranging from 302 to 377 for a fixed Reynolds number of 100 on the flow characteristics has been presented in detail. The flow parameters like wall shear and pressure of wall are increased with increasing Magnetic number and the number of recirculating bubbles increases with decreasing in Magnetic number. Thus, to generate the maximum number of recirculating bubbles,a lower magnetic number is being recommended. The formation of the recirculating zone increases the retention time of fluid which results in the enhancement of heat transfer for a specific surface of a heat exchanger.

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