Numerical Study of Flow Past a Solid Sphere at Moderate Reynolds Number

Sadikin, Azmahani; Yunus, Nurul Akma Mohd; Abdullah, Kamil; Mohammed, Akmal Nizam

doi:10.4028/www.scientific.net/amm.660.674

Cited by 11 publications

(5 citation statements)

References 7 publications

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“…It demonstrates that when the Reynolds number grows, flow separation happens earlier. These findings agree with past researchers [14,17]. This is because as the velocity rises, the flow has more difficulty attaching to the sphere.…”

Section: Fig 8 -Velocity Streamlines With Some References Pointsupporting

confidence: 93%

“…When the flow in the boundary layer becomes turbulent, the drag coefficient lowers as the Reynolds number increases, allowing a separation point to travel further away from the rear body, lowering wake size and pressure drag magnitude. These findings are consistent with prior research, which found that the annotated drag coefficient falls as the Reynolds number increases [14,16].…”

Section: Drag Coefficientsupporting

confidence: 92%

See 1 more Smart Citation

The Effect of Different Reynolds Number On Solid Sphere Using CFD and Its Verification

Azahar,

Ishak,

Sulaiman

et al. 2023

IJIE

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Aerodynamic behaviour of an object depends on several factors, namely shape, size and flow conditions. Thus, CFD simulations are an effective engineering tools that allows major contribution to understand the flow conditions around an object. This study aims to analyse the effect of two typesof spherical modelsthat aresphere and hemisphereon aerodynamics behaviour for different Reynolds number between 100,000 ≤ Re ≤ 800,000. Geometry models are generated using SolidWorkssoftwareand numerical solution is analysedusing ANSYS CFX. The numerical results are later compared with experimental data collected from wind tunnel. At the end of the study, the nature flow around spherical models of different Reynolds number are visualized. It is discovered that the flow behaviour around the spherical model changes as the Reynolds number increases. This finding is parallel with past researchers. These forecasts should assist engineers enhance the application of aerodynamic and hydrodynamic design.

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Section: Fig 8 -Velocity Streamlines With Some References Pointsupporting

confidence: 93%

Section: Drag Coefficientsupporting

confidence: 92%

The Effect of Different Reynolds Number On Solid Sphere Using CFD and Its Verification

Azahar,

Ishak,

Sulaiman

et al. 2023

IJIE

View full text Add to dashboard Cite

show abstract

“…Other studies conducted by Yin and Ong (2020), Constantinescu and Squires (2004), Sadikin et al (2014), andYen et al (2017) demonstrated that the flow past a solid sphere differs from the flow past a circular cylinder, especially in terms of vortex shedding in the wake flow behind the sphere. In the past, numerical analysis studies were performed in order to reach a comprehensive understanding of the flow past a simple body before applying the method to a more complex geometry.…”

Section: Introductionmentioning

confidence: 96%

Influence of Full and Symmetrical Domains on the Numerical Flow around a SUBOFF Submarine Model using OpenFOAM

2023

JAFM

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In this research, we consider the influence of two kinds of domain on the numerical flow around a submarine model. A fully appended SUBOFF submarine model was used, and the structure and characteristics of the flow were investigated under a full domain and a symmetrical domain arrangement. The numerical simulation was carried out using the OpenFOAM software, and the flow was numerically modelled as single-phase and incompressible. The SST k-ω turbulence model was used in both domains, together with an insensitive Spalding wall function to represent the boundary layer near the wall. The results showed that simulations in both the full and symmetrical domains could accurately predict the total resistance. Compared to the symmetrical domain, the resistance value obtained with the full domain was more precise; the symmetrical domain under coarse grid conditions had an error value of 1.34%, whereas the full domain using the same grid size had an error value of 0.6%. Hence, the full domain was superior in terms of predicting the resistance with a coarse grid. Next, the pressure coefficient comparison at the leading edge of the rudder was calculated, where = 0.92, and the symmetric domain was found to have a value of 0.0747 whereas the full domain had a value of 0.236. Compared with the results from experiment (=0.302), the symmetric domain appears to give an underestimate for the pressure distribution at this position. In addition, the flow structures and properties in both domains differ, particularly in terms of the vortical structures generated by the sail and rudders. The simulation results for the full domain reveal that the flow around the SUBOFF model is asymmetric. The full domain was able to capture the flow structures in more detail than the symmetrical domain, and represented the velocity distribution at the propeller plane better. As a result, the full domain must be considered when carrying out propeller analysis and self-propulsion simulations.

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“…In the literature [5,6], some summaries that the flow mechanisms in wake field were not the same in different Reynolds number intervals were given. Flow separation around a sphere occurs when the shear stress is zero [8]. The flow separation angle measured from the front stagnation point decreases with the increasing Reynolds number between 20 and 500.…”

Section: Introductionmentioning

confidence: 99%

The Symmetry and Stability of the Flow Separation around a Sphere at Low and Moderate Reynolds Numbers

Zhou

2021

Symmetry

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The flow separation state reflects the symmetry and stability of flow around spheres. The three-dimensional structures of flow around a rigid sphere at moderate Reynolds number (Re) between 20 and 400 by using finite volume method with adaptive mesh refinement are presented, and the process of separation angles changing from stable to oscillating state with increasing of Re is analyzed. The results show that the flow is steady, and the separation angles are stable and axisymmetric at Re in less than 200. The flow is unsteady and time-periodic, and the flow separation becomes regular fluctuations and asymmetric at Re = 300, which leads to the nonzero value of lateral force and the phase difference between lift and lateral force. At Re = 400, the flow is unsteady, non-periodic, and asymmetric, as is the flow separation. It’s concluded that the flow separation angle increases when Re increases within a range between 40 and 200. With Re continues to increase, the flow separation state changes from stable to periodically regular until quasi-periodically irregular. The vortex structure changes from no shedding to asymmetric periodic shedding, and finally to asymmetric and intermittently periodic vortex shedding. These results have important implications for the stability of flow around spheres.

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Numerical Study of Flow Past a Solid Sphere at Moderate Reynolds Number

Cited by 11 publications

References 7 publications

The Effect of Different Reynolds Number On Solid Sphere Using CFD and Its Verification

The Effect of Different Reynolds Number On Solid Sphere Using CFD and Its Verification

Influence of Full and Symmetrical Domains on the Numerical Flow around a SUBOFF Submarine Model using OpenFOAM

The Symmetry and Stability of the Flow Separation around a Sphere at Low and Moderate Reynolds Numbers

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