DOI: 10.1615/ICHMT.2009.CONV
ISBN Print: 978-1-56700-261-4
ISSN Online: 2642-3499
ISSN Flash Drive: 2642-3502
NUMERICAL ANALYSIS OF EFFECTS OF TRANSVERSAL BAFFLES ON FORCED CONVECTION IN A CIRCULAR TUBE
ABSTRAKT
Conventional sources of energy have been depleting at an alarming rate, which makes future sustainable development of energy use very difficult. Thus, heat transfer enhancement technology plays an important part and it has been developed and widely applied to many applications as heat exchangers for refrigeration, automotives, process industry, solar heater etc. Several techniques for heat transfer enhancement are available. Enhancement of heat transfer performance especially in shell and tube heat exchangers is obtained by introducing baffle inserts. When gas flows in a tube, septa with one or more openings can be used as fins. Furthermore, if the openings are arranged to give a spiral motion around the cylinder axis wall-fluid contact area increases. As a consequence the presence of the septa may significantly augment pressure drops.
In this paper a numerical investigation is carried out on forced convection in circular tubes with septa heated by constant flux. This work extends the analysis carried out by Manca et al. [2008]. The fluid is air and properties are function of temperature. Septa of the same material of the tube are introduced and several shapes and arrangements are analyzed as well as different Re numbers, spacings and heat fluxes applied on the external surface. The investigation is accomplished by means of the commercial code Fluent. A k-e turbulence model is used with enhanced wall treatment options. The aim of this study is to find the shape and arrangement of septa such to give high heat transfer coefficients and low pressure drops.