An improved predictive model for forced-convective heat transfer of turbulent boundary layers with unheated length

Abstract

This study investigates forced convective heat transfer in turbulent boundary layers with unheated starting lengths, focusing on cases where the thermal boundary layer remains thinner than the momentum boundary layer. In these regimes, the thermal layer develops as an internal layer; consequently, the thermal wake disappears and the temperature profile transitions smoothly from a restricted logarithmic region to the freestream. To address the resulting predictive discrepancies, we adopt a boundary layer evolution approach — based on conservation of momentum and energy to predict the skin friction coefficient (Cf) and the Stanton number (St). We propose a standard log–wake model and develop a..