Numerical Simulation of Drag Reduction on a Square Rod Detached with Two Control Rods at Various Gap Spacing via Lattice Boltzmann Method

Abstract

Numerical simulations are performed to examine the effect of size of control rods (d1) and spacing ratio (g) on flow around a square rod with upstream and downstream control rods aligned in-line using the lattice Boltzmann method (LBM). The Reynolds number (Re) is fixed at Re = 160, while the spacing between the main rod and control rods is taken in the range 1 ≤ g ≤ 5 and the size of the control rod is varied between 4 and 20. Seven different types of flow mods are observed in this study at different values of g and d1. Variation in force statistics, like mean drag coefficient (Cdmean), Strouhal number (St), root mean square values of drag (Cdrms) and lift coefficients (Clrms), and percentage reduction in mean drag coefficient is discussed in detail. It was examined that vortex shedding completely suppressed at (g, d1) = (1, 12), (2, 12), and (2, 16) where steady flow mode exists. Moreover, it was found that at large gap spacing, where g = 5, the effect of control rods on the main rod vanishes. Due to this strong vortex shedding produced and as a result, maximum value of Cdmean is found at (g, d1) = (5, 8). The negative values of mean drag force are also observed at some gap spacing and size of control rods are due to the effect of thrust. Furthermore, the maximum percentage reduction in Cdmean is 121%, found at (g, d1) = (2, 20).

Numerical Investigation of Convective Heat Transfer and Fluid Flow Past a Three Square Cylinders Controlled by a Partition in Channel

“…As mentioned earlier, several studies exist in the literature that treats the flow of fluids around one or more obstacles (Ali et al, 2012;Chatterjee et al, 2013;Dey, 2021;Dhiman et al, 2005;Guo et al, 2020;Han et al, 2013;Islam et al, 2016;Kumar et al, 2015;Malekzadeh et al, 2012;Manzoor et al, 2020;Rashidi et al, 2015;Sohankar et al, 2018;Wu et al, 2006;Zhou et al, 2005). Han et al (Han et al, 2013)used the finite element scheme (CBS) to study the flow around two square cylinders arranged horizontally side by side at a fixed Reynolds number.…”

“…Very limited research has been conducted on flow control coupled with heat transfer around multiple cylinders. While there are numerical and experimental investigations (Ali et al, 2012;Manzoor et al, 2020;Turki, 2008) that study flow control with or without coupling to heat transfer around a single cylinder using simple control instruments (passive control). Turki et al (Turki, 2008) using a splitter plate for passive control of vortex shedding behind a square cylinder in laminar flow.…”

“…Likewise, numerical simulations were conducted by Manzoor et al (Manzoor et al, 2020) to examine the effect of control rod size (4 ≤ d1 ≤ 20) and spacing ratio (1 ≤ g ≤ 5) on the flow around a square cylinder at a fixed Reynolds number (Re = 160) using the lattice Boltzmann method (LBM). They found that vortex shedding is completely suppressed at (g, d1) = (1, 12), (2, 12), and (2, 16) where the stable flow mode exists.…”

Similarities of Flow and Heat Transfer around a Circular Cylinder

“…For instance, the motion of swimming and flying animals [1], growth of stalagmites [2], fall motion of hailstones [3], motion of pollutants in the atmosphere [7], complex motion of the drill string in the field of petroleum engineering [8], and flow over bridge piers, chimney stacks, offshore structures, and tower structures in civil engineering [9], aircrafts in the field of aerospace [10], nuclear fuel rods in the atomic field [5], power battery cooling structures in the field of new energy vehicles [11], heat exchanger tubes in thermal engineering [12], etc. The fluid dynamic drag [13][14][15], active and passive methods for drag reduction [16][17][18], boundary layer flow [19], flow-induced vibration [5], behavior of turbulent fluid motion [20], and instability in the wake shear layer [21][22][23] are of interest in numerous fields. Owing to its practical importance in engineering applications and theoretical significance in understanding fundamental fluid mechanics, the flow over a circular cylinder has attracted extensive study interest from both scientists and engineers.…”

Analytical mathematical schemes: Circular rod grounded via transverse Poisson’s effect and extensive wave propagation on the surface of water

“…Many nonlinear physical phenomena in nature are described by nonlinear partial differential equations (PDEs). For deliberative speedy development of symbolic computation systems [1][2][3][4][5], the search for the exact solutions of nonlinear equations has attracted a lot of attention [6][7][8][9] as the exact solutions make it possible to research nonlinear physical phenomena comprehensively and facilitate testing the numerical schemes [10][11][12][13][14]. In the last two decades, various approaches have been proposed and applied to the nonlinear equations of PDEs, such as homogeneous balance method [15,16], extended tanh-function method [17][18][19][20], Jacobi elliptic function expansion method [21], simple equation method [22][23][24], (G/G′)-expansion method [25][26][27], Hirotas bilinear method [28], Exp function method [29], general projective Riccati equation method [30], modified simple equation method [31][32][33], improved direct algebraic technique, [34,35], auxiliary scheme [36] and so on [37][38][39][40][41][42]…”