Presented in this paper is an experimental investigation of the flow structure near the aperture of a scaled down laboratory model of a Hybrid Solar Receiver Combustor (HSRC). The aim of the work is to evaluate the flow characteristics in the vicinity of the cavity aperture as function of the external flow velocity, simulating wind, and the flow patterns within the cavity induced by four jets simulating the burners. This interaction is expected under the mixed mode of utilizing both solar and combustion energy. Under this mode, ingress/egress into and from the solar cavity receiver due to the pressure difference between the inside of the cavity and the ambient, leads to convection losses, particularly under high wind velocities. In the current study, a simplified and scaled down HSRC geometry is used. It includes a cylindrical cavity of diameter 74 mm and length 225 mm. The configuration includes four jets with a diameter of 3.5 mm to model burners with different inclination angles of αjet=25° and 50° and different azimuth angles of γjet=0°, 5°and 15°. The tests were conducted in the water channel using Particle Image Velocimetry (PIV) technique to measure the flow field. The conducted experiments aimed to investigate the influence of jet inclination and azimuth angle on the flow patterns through the aperture of the cavity. Furthermore, the influence of external flow changes on the flow pattern inside the cavity is investigated by adjusting the water channel stream velocity to 0.0, 0.08, 0.16 and 0.24 m/s. The results show that the flow behavior through the aperture strongly depends on two main factors. Firstly the flow fields induced by the variation of the inclination angle of the jets and secondly the external stream velocity. These results point to a complex interaction of the external and internal flows and highlight the need for the development of a fluidic barrier to de-couple them.
|Original language||English (US)|
|Title of host publication||Proceedings of the 21st Australasian Fluid Mechanics Conference, AFMC 2018|
|Publisher||Australasian Fluid Mechanics Society|
|State||Published - Jan 1 2018|