Computation Of Natural Convection Research Articles

Computation of Natural Convection in Channels With Pin Fins

In this paper, we numerically analyze the possibility of using buoyant flow in the display panel of a laptop for electronics cooling. Three-dimensional (3-D) channels with embedded pin fin arrays are analyzed using an unstructured finite volume method. Studies have been performed with a uniform heat flux boundary condition applied on the inner wall as well as for a constant inner wall temperature condition; the outer wall in all cases is exposed to the ambient. A single periodic module is selected in the lateral direction. In the axial mean flow direction, however, the entire height of the display channel is considered. Buoyancy has been modeled using Boussinesq approximation. A range of Rayleigh numbers, panel inclinations, and pin fin arrangements are considered. Local and global flow and heat transfer results are obtained including Nusselt numbers as well as local temperature and velocity fields. The results are useful in designing augmented cooling schemes in portable electronics.

550 前処理付反復法を用いた自然対流の 3 次元数値計算

550 前処理付反復法を用いた自然対流の 3 次元数値計算

Computation of natural convection in two-dimensional cavities with Chebyshev polynomials

A semi-implicit spectral method for the computation of buoyancy induced two-dimensional flow of a viscous incompressible fluid is presented. The incompressible Navier-Stokes equations expressed in terms of the primitive variables velocity and pressure, and an additional equation for the temperature, are considered. All the variables are expanded in double truncated series of Chebyshev polynomials. The pressure distribution at the boundary of the computational domain is determined by means of an influence matrix technique in order to satisfy the incompressibility condition everywhere in the field. The algorithm is applied to the classical problem of natural convection of a Boussinesq fluid within a differentially heated vertical square cavity. Results show that, for a Prandtl number of 0.71 corresponding to air and up to Rayleigh numbers of 106, very accurate solutions are obtained with a spatial resolution of 33 polynomials in each direction. New interesting phenomena are shown for higher values of the Rayleigh number.

The finite‐difference computation of natural convection in a rectangular enclosure

AbstractA study is made of the natural convection of a fluid contained in a long horizontal enclosure of rectangular cross section with one vertical wall heated and the other cooled. Two‐dimensional motion is assumed. The governing vorticity and energy transport equations are solved by an implicit alternating direction finite‐difference method. Transient and steady state isothermals and streamlines are obtained for Grashof numbers up to 100,000 and for height‐to‐width ratios of 1, 2, and 3.