Rapid thermal transport at rough solid-fluid interface: Evaporation and explosive boiling on concave nanostructure

•Rough nanostructured surface can effectively delay the bubble nucleation and growth.•Atomic-scale roughness affects the solid-liquid interfacial thermal resistance.•High roughness element shows a better thermal performance with a larger CHF The concave nanostructure presents a better boiling performance compared to convex one, however, the surface roughness plays a key role in thermal transport at solid-fluid interface. In this work, we adopted the non-equilibrium molecular dynamics simulation to investigate the effect of the internal surface roughness on the boiling heat transfer performance in concave nanostructure. It shows that the presence of atomic-scale roughness leads to heat transfer deterioration and enhancement during the evaporation and the explosive boiling processes, respectively. This finding, which is contradictory with the general understanding, is attributed to the difference in interfacial thermal resistance. It shows that the heat transfer performance is strongly dependent on the configuration of roughness elements. The low solid fraction configuration has a better heat transfer performance and can postpone the start of boiling process.