Numerical Simulation of Convective Heat Transfer for In-Flight Icing

Convective heat transfer is the primary mechanism during glaze ice accretion. Hence, modeling heat transfer over rough surfaces and the laminar-turbulent transition is essential in determining the final ice shape. The chapter presents the prediction of ice shapes via an improved treatment of the integral boundary layer. The onset of the laminar-turbulent regime is evaluated using an intermittency function to represent the transition region rather than an abrupt laminar-turbulent transition occurring at a point. An equivalent sandgrain roughness height and its consequent rough Stanton number correlation are evaluated. A modified thermal wall function) is presented that considers the effect of roughness height acting as a thermal insulator, countering the Reynolds number’s effect of intensifying the heat transfer rates. The local heat transfer coefficient is calculated for a rough cylinder and icing airfoils. The results are compared with experimental data and open-source numerical simulations, showing a better prediction of ice shapes.