## THERMAL SCIENCE

International Scientific Journal

### COMPUTATIONAL ANALYSIS OF TRANSIENT TURBULENT FLOW AND CONJUGATE HEAT TRANSFER CHARACTERISTICS IN A SOLAR COLLECTOR PANEL WITH INTERNAL, RECTANGULAR FINS AND BAFFLES

**ABSTRACT**

The poor thermal exchange between the absorber and the fluid in the solar air flat plate collector, gives the bad performance and the mediocre thermal efficiency. The introduction of obstacles in the dynamic air vein of the solar collector in order to obtain a turbulent flow is a technique that improves the thermal exchange by convection between the air and the absorber. This article present a computational analysis on the turbulent flow and heat transfer in solar air collector with rectangular plate fins absorber and baffles which are arranged on the bottom and top channel walls in a periodically staggered way. To this end we solved numerically, by the finite volumes method, the conservation equations of mass, momentum and energy. The low Reynolds number k-ε model was adopted for the taking into account of turbulence. The velocity and pressure terms of momentum equations are solved by the SIMPLE algorithm. The parameters studied include the entrance mass flow rate of air. The influence of the mass flow rate of air on the axial velocity and the efficiency of upward type baffled solar air heaters have been investigated numerically. The results show that the flow and the heat transfer characteristics are strongly dependent on mass-flow rate of air and the presence and/or the absence of the baffles and fins in the solar collector. It was observed that increasing the Reynolds number will increase the efficiency of the solar panel, as expected.

**KEYWORDS**

PAPER SUBMITTED: 2009-02-07

PAPER REVISED: 2009-02-28

PAPER ACCEPTED: 2009-03-26

**THERMAL SCIENCE** YEAR

**2010**, VOLUME

**14**, ISSUE

**1**, PAGES [221 - 234]

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