Optimal wall spacing for heat transport in thermal convection

The simulation of RB flow for Ra up to 1 x 10¹⁰ is computationally expensive in terms of computing power and hard disk storage. Thus, we gratefully acknowledge the computational resources supported by Leibniz-Rechenzentrum Munich. Compared to Γ=1 situation, a new physical picture of heat transport is identified here at Γ_opt for any explored Ra. Therefore, a detailed comparison between Γ=1 and Γ=Γ_opt is valuable for our further research, for example, their vertical temperature and velocity profiles. Additionally, we plan to compare the fluid with different Pr under geometrical confinement, which are computationally expensive for the situations of Pr<<1 and Pr>>1.