Fluctuations in Heat Flux as Observed in the Expanded Flow from the RENT (Re-Entry Nose Tip) Facility Arc Heater.

摘要

A large number of heat flux profiles from the test jet of the Re-Entry Nose Tip (RENT) Test Leg of the 50MW Facility have been evaluated. These were obtained using null-point calorimeters. Only those profiles taken at fixed arc heater conditions of 1500psig arc heater air pressure and 2600amps arc current were used. The heat flux profiles showed that large fluctuations in heat flux were present in the test stream for all nozzles used. The main frequency of the fluctuations was found to be in the 100Hz range. The fluctuations were approximately plus or minus 20% about the mean level. It is concluded that the average heat flux level determined from a minimum of ten profiles should be established for each arc heater operating condition. This value should then be used as input information for analysis of ablation behavior. (Author)