Experimental heat transfer coefficients from ice-roughened surfaces for aircraft deicing design

Experimental Stanton numbers are presented for seven aluminum model casting s of ice-roughened surfaces in parallel air flow for Re-x ranging from 5.3 x 10(4) to 1.3 x 10(6). The Stanton numbers were generally higher than thos e far previous studies with hemispherical and truncated cone roughness elem ents, and the majority of the data were in the fully turbulent regime, In g eneral, the rime feather ice roughness produced the highest rate of heat tr ansfer, followed by the rough glaze roughness, the smooth rime roughness, a nd the smooth glaze roughness, respectively. in the fully developed turbule nt regime the! local Stanton number could be described by a power law of th e form St(x) = a Re-x(m) Pr-0.4 where a and m correlated well with the newl y defined Index of Random Roughness and the roughness height, respectively. This work provides a set of measured values of the Stanton number, specifi c to the case of stochastically accreted ice on aircraft surfaces, needed f or the effective design of in-flight design systems.