EXPERIMENTAL INVESTIGATION ON IMPINGEMENT HEAT TRANSFER FROM RIB ROUGHENED SURFACE WITHIN ARRAYS OF CIRCULAR JETS: Correlation

摘要

Impingement heat transfer is one of the useful tooling methods for high temperature gas turbine blades and/or guide vanes in aeroengines. Alter the cooling jet impinges on the leading edge of the turbine blade and/or guide vane, it flows downstream and turns to be the initial crossflow for the aft row of impinging jet. The process of impingement heat transfer is quite complicated, especially when the target surface is rib roughened In this paper, the correlation of the impingement heat transfer characteristics has been analyzed based on thousands of experimental data in different parameter matching conditions (Re{sub}j = 7000～20000, (G{sub}c/G{sub}j=0～0.5, X{sub}n=5～15, Z{sub}n =1.5～5, p/e=5～12 and e/d = 0.5～1.5). The impingement heat transfer characteristics can be generally expressed as a functional formulation with the exponential functions of Re{sub}j, Z{sub}n, X{sub}n e/d and p/e, and a polynomial function of G{sub}c/G{sub}j. The interaction among the parameters are reflected in the exponents i, j, k, n, etc. and the weighing coefficients. By the regression processing to the experimental data, the exponents and the weighing coefficients are determined. The correlation equation of impingement heat transfer characteristics to the parameters has been finally concluded. Comparison shows that the correlation results are in good agreement with the experimental data.