Numerical investigation of unsteady natural convection from a heated cylinder in a square enclosure

Date

2015-07-06

Author

Bozkaya, Canan

Metadata

Show full item record

Item Usage Stats

261
views

0
downloads

A numerical study of two dimensional, unsteady, incompressible natural convection flow and heat transfer is performed in a square enclosure involving a heated circular cylinder. The natural convection is driven by a temperature difference between the cold outer square and hot inner circular cylinders. The temperature of the inner cylinder varies sinusoidally with time about a fixed mean temperature while the outer enclosure is kept at a lower constant temperature. The problem under consideration, which is governed by the coupled momentum and energy equations, is discretized by the dual reciprocity boundary element method in space and an implicit backward finite difference scheme is applied for temporal discretization. Numerical simulations are carried out for several values of the amplitude and the period of the inner cylinder temperature when the Rayleigh number is in the range 103 ≤ Ra ≤ 106. The results are visualized in terms of streamlines, isotherms and surface averaged Nusselt number to assess the effects of the sinusoidal time varying temperature on the fluid flow and temperature distribution. It is observed the size and shape of the vortices observed in streamline profile and the distribution of the isotherms vary drastically due to the oscillating cylinder temperature. Furthermore, the heat transfer rate enhancement increases with the temperature amplitude and Rayleigh number. On the other hand, a backward heat transfer from fluid to cylinder occurs at phases when the cylinder temperature becomes less than the temperature of the surrounding fluid for high amplitudes of cylinder temperature.

Subject Keywords

Natural convection, DRBEM, Sinusoidally heated cylinder, Square enclosure

URI

https://hdl.handle.net/11511/87185

Conference Name

Advances in Boundary Element & Meshless Techniques XVI BETEQ (2015)

Collections

Department of Mathematics, Conference / Seminar

Suggestions

OpenMETU
Core

Magnetohydrodynamic convection of Cu-water nanofluid in a square cavity with a circular cylinder Bozkaya, Canan (2016-01-01) The hydromagnetic free convection of a Cu-water nanofluid in a square cavity involving an adiabatic circular cylinder is numerically investigated in the presence of an inclined uniform magnetic field. The left and right walls of the cavity are kept at constant hot and cold temperatures, respectively, while the horizontal walls are assumed to be adiabatic. The coupled nonlinear equations of mass, momentum and energy governing the present problem are discretized using the dual reciprocity boundary element met...
FEM solution to natural convection flow of a micropolar nanofluid in the presence of a magnetic field TÜRK, ÖNDER; Tezer, Münevver (2017-03-01) The two-dimensional, laminar, unsteady natural convection flow in a square enclosure filled with aluminum oxide ()-water nanofluid under the influence of a magnetic field, is considered numerically. The nanofluid is considered as Newtonian and incompressible, the nanoparticles and water are assumed to be in thermal equilibrium. The mathematical modelling results in a coupled nonlinear system of partial differential equations. The equations are solved using finite element method (FEM) in space, whereas, the ...
Numerical investigation of natural convection from vertical plate finned heat sinks Çakar, Kamil Mert; Albayrak, Kahraman; Department of Mechanical Engineering (2009) The steady-state natural convection from vertically placed rectangular fins is investigated numerically by means of a commercial CFD program called ICEPAK. The effects of geometric parameters of fin arrays on the performance of heat dissipation from fin arrays are examined. In order to simulate the different fin configurations and compare the results with literature, two experimental studies from literature are selected. Optimum fin spacing for both studies are found numerically and compared with experiment...
Numerical study of Rayleigh Bènard thermal convection via solenoidal bases Yıldırım, Cihan; Tarman, Işık Hakan; Department of Engineering Sciences (2011) Numerical study of transition in the Rayleigh-B\'enard problem of thermal convection between rigid plates heated from below under the influence of gravity with and without rotation is presented. The first numerical approach uses spectral element method with Fourier expansion for horizontal extent and Legendre polynomal for vertical extent for the purpose of generating a database for the subsequent analysis by using Karhunen-Lo\'eve (KL) decomposition. KL decompositions is a statistical tool to decompose the...
Numerical Simulation of Reciprocating Flow Forced Convection in Two-Dimensional Channels Sert, Cüneyt (ASME International, 2003-5-20) <jats:p>Numerical simulations of laminar, forced convection heat transfer for reciprocating, two-dimensional channel flows are performed as a function of the penetration length, Womersley (α) and Prandtl (Pr) numbers. The numerical algorithm is based on a spectral element formulation, which enables high-order spatial resolution with exponential decay of discretization errors, and second-order time-accuracy. Uniform heat flux and constant temperature boundary conditions are imposed on certain regions of the ...

Citation Formats

C. Bozkaya, “Numerical investigation of unsteady natural convection from a heated cylinder in a square enclosure,” Valencia, Spain, 2015, p. 248, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/87185.