Convection from manufactured ice roughness with varying flux boundary conditions.

It is well understood that aircraft wing icing adds weight, increases drag coefficients, decreases lift coefficients, and reduces stall margin, which can lead to aircraft accidents. To predict the shape of these ice accretions, codes, such as the NASA LEWICE code, have been created that step through time and solve an energy balance for an iced airfoil. A critical part of this energy balance is convection over the initial ice roughness. However, determining the convective heat transfer over the initial ice roughness is difficult. Previous methods have been developed for measuring the convective heat transfer for ice roughness with constant thermal boundary conditions. This work investigates the effect of variable heat flux boundary conditions on convective heat transfer, and improves upon the techniques used to obtain convective heat transfer measurements for realistic ice roughness patterns.