The temperature distribution and the difference with the ambient temperature of the primary mirror are crucial factors affecting the observational quality of the solar telescope.

We designed a flow field structure of the primary mirror temperature control system based on the 2.5-meter Wide-field and High-resolution Solar Telescope(WeHoT),analyzed the flow conditions and heat transfer capacity of the overall flow field,and then carried out five stages of optimization iteration and simulation guided by the analysis results.A flow field structure for the primary mirror temperature control system with high efficiency and high uniformity is summarized.

The simulation results for the final solution indicate an average surface temperature of the primary mirror at 20.064◦C,with a maximum temperature difference within the reflective surface of 0.809◦C,and a reduced difference with the ambient temperature of 0.411◦C.Surface thermal deformation is less than 0.2μm,with an RMS value of 18.05 nm,achieving the ideal state.

This work can provide a theoretical foundation and valuable insights for future research on the temperature control system of the primary mirror in large-aperture solar telescopes.