Ice accretion with varying surface tension

Overview of Icing Physics Relevant to Scaling

“…This consistently good agreement between n e and n a over a range of conditions including both fully rime and fairly warm glaze argued against the contention that the Messinger freez- ing fraction formulation neglects any important surfacewater effects. On the contrary, for Appendix C icing conditions, the experimental results appeared to validate the Messinger freezing fraction formulation expressed in equation (28).…”

“…These beads sometimes were swept downstream and sometimes froze in place. Bilanin 23,28 also argued that drop splashing on impact might affect the shape of the ice accreted.…”

“…Similar observations were made by Bilanin and Anderson. Figure 8 includes published 28 and unpublished data from their studies and compares ice shapes with and without surfactant addition to the spray for velocities of 105, 150 and 209 mph. The shaded ice shapes were obtained with the NASA Glenn IRT de-mineralized water supply with no surfactant added, and the shape represented by the solid line resulted from surfactant addition to the water.…”

“…This was done by Anderson and Tsao 22 and the results compared with the analytical freezing fraction formulation presented in equation (28). To distinguish between the experimentally-derived and analytical freezing fractions, n e and n a will be used, respectively.…”

“…By using n 0 as the heat-balance parameter to match for scale studies, the implicit assumption is that if n 0,S = n 0,R then n will also match everywhere. Furthermore, strictly speaking, equation (28) applies only to a clean airfoil. As ice accretes, the stagnation freezing fraction can be expected to change because the geometry is continually changing.…”