Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
THERMO-HYDRAULIC SENSITIVITY ANALYSIS OF SOLAR AIR HEATER CHANNEL WITH DELTA-WINGLET VORTEX GENERATORS
Submission Author:
Daniel Dezan , SP , Brazil
Co-Authors:
Daniel Dezan, Andre Damiani Rocha, Wallace Ferreira
Presenter: Daniel Dezan
doi://10.26678/ABCM.COBEM2019.COB2019-0446
Abstract
The thermal-hydraulic performance of solar collectors depends on the ability of the working fluid to remove the heat stored on those devices. Basically, the benefits of heat transfer enhancement by using special surface geometries are due to an increase of the convective heat transfer coefficient or/and surface area. The use of modified surfaces reduces the thermal resistance and thus provides an increase of the convective heat transfer coefficient. However, the heat transfer enhancement is always associated with pressure drop increasing. This research deals with the numerical investigation of the thermal-hydraulic performance of flat-plate solar air heaters with delta winglet vortex generators by using Computational Fluid Dynamics. The flow is assumed to be incompressible, turbulent and steady. The k-ω SST turbulence model is employed to treat the turbulence phenomena. Three rows of delta-winglet pairs are placed in the channel. The Reynolds number, based on hydraulic diameter, is kept constant (ReDh=5000). It is well known that there are a lot of parameters which can affect the thermal-hydraulic performance of LVGs. It is evident that the amount of the design of experiments to maximize the thermal-hydraulic performance of SAH can be enormous. Thus, it is statically investigated the effect of the chord, height and angle of attack of three rows of delta-winglet pairs on the averaged Nusselt number and friction factor. For this task, Morris method is used for classifying and ranking the main and interaction effects among the input variables. Finally, the flow pattern and heat transfer characteristics are discussed and the main conclusions are presented.
Keywords
longitudinal vortex generators, delta-winglet vortex generator, solar air heaters, renewable energy, Computational Fluid Dynamics
