INTRODUCTION

Among all concentrating solar power (CSP) techniques, parabolic dishes are the most efficient system due to their higher concentration ratio and temperatures achieved inside the cavity receivers. Due to installation in the open terrine, the system efficiency is affected by the heat loss from the receivers [1]. Heat losses from the receiver occur by convection, conduction and radiation. As a result of complex velocity and temperature filed around the receiver, determination of convective heat loss is much more complicated among all these heat transfer modes [2]. All the studies reviewed so far, however, indicate that there is a significant lack of work on the impact of parabolic dishes on wind flow and heat loss at the receiver [2]. Numerous studies, highlighted in review of the field by Wu et al. [2], have examined the convection heat loss by treating the receiver as an isolated entity. . This decoupling provides a simplified regime that would be accurate for no wind condition and for certain tilt angles (􀀓). However, the presence of the dish structure in the flow field have a significant effect on the heat loss, particularly mixed and forced convection [3, 4]. This work is aimed to investigate the convective heat losses from the receiver in the presence of the dish structure in the flow field.