First Results of Calibration and use of the HEG

This paper deals with the experimental possibilities, provided by the new high enthalpy wind tunnel HEG, to study the effects of oxygen and nitrogen dissociation in experiments where this reaction occurs over a sufficiently short distance in stagnating flows. The particulars of the large facility, its capability to operate in tailored mode and the drawbacks of relatively large test times at high density and enthalpy will be dicussed in the light of the latest calibration experiments. After the discussion of the calibration status of the HEG, samples of aerothermodynamic tests performed in the HEG will be discussed. Some of these experiments are reconfirmations of experiments like flow over blunt bodies performed in the Australian tunnels T3 and T4 where the difference lies in the new instrumentation applied to the same flow problems, others are new studies of external aerothermodynamics like the experiments on shock/shock interactions. The significance of the dissociation effects in the above experiments is poited out