Numerical study of laminar and turbulent natural convection from a stack of solid horizontal cylinders

Rath, Subhasisa; Dash, Sukanta Kumar

doi:10.1016/j.ijthermalsci.2019.106147

Cited by 22 publications

(4 citation statements)

References 28 publications

(41 reference statements)

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“…The optimal partial differential equation for predicting the values of a mass function (𝑀) in 2D turbulent flow domain is Equation (42). Calculating the gradient of average concentration in the cylinder's vicinity is also necessary because this gradient is directly integrated along the cylinder's height to get at the total average concentration departure the cylinder, which is directly set as a 𝑀 boundary value at the cylinder's top border.…”

Section: Mass Functionmentioning

confidence: 99%

“…If the turbulent kinematic viscosity

{\nu }_t

is assume zero then the governing equation similar to laminar flow [42, 51]. Hence, to know the worthy of numerical outcomes, by assuming

{\nu }_t

is zero, the numerical code for the time‐averaged finite difference solution of maximum velocity at

X = 1.0

along with engineering quantities of interest is validated with the existing literature of Ganesan and Rani [46].…”

Section: Simulated Outcomes and Analysismentioning

confidence: 99%

“…Also, the k-ε turbulence approach was used by Wang et al [41] to visualise the liquid motion field surrounded by circular cylinders. Recently, Rath and Dash [42] investigated the 3D computational analysis of the Rayleigh number in buoyancy-induced motion past a solid horizontal cylinder. They explained that the turbulent kinematic viscosity disappearance causes the turbulent flow to become laminar.…”

Section: Introductionmentioning

confidence: 99%

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Turbulent heat and mass lines in finite difference regime

S P,

Reddy,

Basha

2023

Z Angew Math Mech

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Finite difference modelling of turbulent heat and mass flow visualization finds numerous applications in atmospheric flows/oceanic currents, wind turbines, thermal transfer in nuclear reactors, drag in oil pipelines, cooling of industrial machineries, and to investigate the complexity, dynamic and chaotic nature of the physical system. A turbulent phenomenon is effectively implemented in engineering, physics, earth sciences, bio‐engineering and medicine. Hence, motivated by the advantages of turbulence in various engineering fields, in the current article, a finite difference analysis is performed to demonstrate the k‐ε turbulence model‐based heat and mass lines visualization in boundary layer regime under turbulent buoyancy‐driven convective conditions along a cylinder. Turbulent flow characteristics are accurately explored by deploying the classical Newtonian flow model. Further, to accomplish a more sophisticated finite difference simulation, the effects of extra kinetic energy and its dissipation rate equations are considered. The produced Navier‐Stokes equations for time‐dependent turbulent heat and mass transmission are rendered to non‐dimensional by deploying suitable dimensionless numbers. The advanced coupled nonlinear turbulent unsteady buoyancy‐motivated vertical convection problem is then solved with a well‐sophisticated finite difference scheme such as Crank‐Nicolson technique using computational software. Authentication of current results with former solutions over a range of buoyancy number, Schmidt, and Prandtl parameters are presented. An extensive tabular and graphical discussion along with contours, heat and masslines visualization is included to enumerate the hydro‐dynamic, thermal and mass diffusion behaviour for the impact of emerged regulating numbers in the Prandtl regime. It is confirmed that, the accelerating turbulent buoyancy‐ratio number, maximizes the velocity, kinetic energy and dissipation rate at . Further, the numerical values of laminar thermal and mass diffusion rates are monotonically enhanced when compared to the turbulent values. Also, to verify the current findings, the authors compared the LRN k‐ε model turbulent results with the existing solutions and found good agreement. Further, the uniqueness and novelty of the current investigation is the exploration of heat and masslines in unsteady buoyancy‐driven convection regime under the influence of k‐ε turbulence model which extends the former studies and offers a more precise appraisal of the thermal and mass diffusion lines via the Crank‐Nicolson analysis.

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Section: Mass Functionmentioning

confidence: 99%

“…If the turbulent kinematic viscosity

{\nu }_t

is assume zero then the governing equation similar to laminar flow [42, 51]. Hence, to know the worthy of numerical outcomes, by assuming

{\nu }_t

is zero, the numerical code for the time‐averaged finite difference solution of maximum velocity at

X = 1.0

along with engineering quantities of interest is validated with the existing literature of Ganesan and Rani [46].…”

Section: Simulated Outcomes and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Turbulent heat and mass lines in finite difference regime

S P,

Reddy,

Basha

2023

Z Angew Math Mech

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“…Several researchers have studied this classical model problem under constant thermophysical properties (that is, constant viscosity and thermal conductivity with negligible heat generation) in different contexts. Some of the important contributions to these model problems where the flow is two-dimensional are listed in Prasad et al, 2014, Zainuddin et al, 2015, Mohamed et al, 2016, Prasad et al, 2016, Zokri et al, 2018, Rath and Dah, 2020. Appreciable research has been carried out in the modeling and simulation of problems that describe the flow of Newtonian fluids under both linear heat generation and Boussinesq approximation in several geometries.…”

Section: Introductionmentioning

confidence: 99%

Importance of convective boundary layer flows with inhomogeneous material properties under linear and quadratic Boussinesq approximations around a horizontal cylinder

Opadiran

Okoya

2021

Heliyon

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This study investigates boundary layer flows with inhomogeneous material properties driven by natural convection using linear and quadratic Boussinesq approximations around a horizontal cylinder. The cylinder's surface was kept at a uniform temperature. The governing equations for the setup were formulated from the principles of mass continuity, momentum and energy under realistic assumptions. Four coupled partial differential equations were obtained and reduced using stream function to two. Using perturbation techniques with one spatial coordinate as the perturbation parameter, the partial differential equations were further reduced to a set of nonlinear coupled ordinary differential equations. The fluid's velocity, as well as the temperature distributions, were computed and analyzed using the Maple 17 platform. The results obtained were consistent with existing results from reference literature. Further analysis of the embedded flow parameters was also carried out and analyzed with relevant tables and graphical illustrations for the linear and quadratic Boussinesq approximations. The results of the study show a fundamental difference between the linear and quadratic Boussinesq approximation alongside an interconnection between constant and variable thermophysical properties.

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