HEAT TRANSFER MEASUREMENTS OF THE FIRST EXPERIMENTAL LAYER OF THE FIRE Ⅱ REENTRY VEHICLE IN EXPANSION TUBES

摘要

The present study focused on simulating a trajectory point towards the end of the first experimental heatshield of the FIRE Ⅱ vehicle, at a total flight time of 1639.53s. Scale replicas were sized according to binary scaling and instrumented with thermocouples for testing in the Ⅹ1 expansion tube, located at The University of Queensland. Correlation of flight to experimental data was achieved through the separation, and independent treatment of the heat modes. Preliminary investigation indicates that the absolute value of radiant surface flux is conserved between two binary scaled models, whereas con-vective heat transfer increases with the length scale. This difference in the scaling techniques result in the overall contribution of radiative heat transfer diminishing to less than 1 % in expansion tubes from a flight value of approximately 9-17%. From empirical correlation's it has been shown that the St (Re)~(1/2) number decreases, under special circumstances, in expansion tubes by the percentage radiation present on the flight vehicle. Results obtained in this study give a strong indication that the relative radiative heat transfer contribution in the expansion tube tests is less than that in flight, supporting the analysis that the absolute value remains constant with binary scaling.