Influence of groove orientation and number on pool boiling heat transfer of water: experimental analysis and ANN modeling

• A study of effect of groove geometry on the flat surface was performed. • The heat transfer coefficient for the grooved surfaces is higher than the base surface. • The heat flux of the beginning of nucleate boiling for the grooved surfaces is lower than the base surface. • As the number of grooves for the grooved heat transfer surface increases, the heat transfer coefficient increases. • The surface heat transfer coefficient with the concentric grooves is higher than the surface heat transfer coefficient with the parallel grooves. This research examines how the orientation of surface grooves influences the pool boiling heat transfer coefficient (HTC) of pure water under atmospheric pressure on a flat heating surface. Grooves with identical geometric dimensions (width, depth, and pitch) were fabricated in two distinct patterns: parallel and concentric. Experimental measurements were complemented by predictions obtained using an artificial neural network (ANN) model. The applied heat flux ranged from 0 to 212 kW·m⁻², and test surfaces included configurations with 0–4 grooves. Results demonstrated that all grooved surfaces exhibited higher HTC values compared with the smooth reference surface, and increasing the groove count enhanced heat transfer performance. For parallel grooves, HTC improvements averaged 32–38%, while concentric grooves achieved gains in the range of 19–90%. The ANN model showed good agreement with the experimental data within the investigated range. Under identical groove geometry, concentric patterns consistently produced higher HTC values than parallel ones, indicating that groove orientation plays an important role in pool boiling heat transfer enhancement.