Radiation: Conical Solar Collector

Conical Solar Collector CFD Simulation in ANSYS Fluent

Introduction

Solar energy represents the largest available energy source in the world, offering a clean, inexpensive, and virtually inexhaustible resource. Solar water heaters operate by absorbing solar energy through collector plates, with heating efficiency varying depending on the collector type; the heated water is typically stored in a double-walled, thermally insulated reservoir capable of maintaining temperature for up to three days. This project simulates heat transfer within a conical solar collector containing water, using ANSYS Fluent to analyze how the collector absorbs sunlight and warms the water inside its tank. The computational domain consists of a cubic air region with a velocity-inlet (1 m/s) and a pressure outlet, along with the conical collector itself, which includes a water inlet (0.01 m/s) and a pressure outlet, and features a glass layer and a steel layer to minimize convective heat loss.

Geometry and Mesh

The geometry, comprising the fluid domain and the conical solar collector, was designed in SpaceClaim and meshed in ANSYS Meshing, resulting in an unstructured mesh totaling 2,948,101 elements.

Methodology

The energy equation and a radiation model, using the solar ray tracing method combined with the Discrete Ordinates (DO) model, were activated to capture solar heating effects within the collector. Fluid flow behavior was resolved using the k-epsilon turbulence model with standard wall functions.

Results and Conclusion

Contours of velocity, temperature, and streamlines were obtained to characterize the thermal and flow behavior within the collector. The average temperature of the collector walls reaches 308.67 K, while water entering the collector at 298.15 K is progressively heated to an outlet temperature of 306.8 K. The total heat transfer through the collector wall was calculated as 773 W, confirming the effectiveness of the conical design in capturing solar radiation and transferring thermal energy to the circulating water.