The dual thin-film probe for high-frequency flow temperature measurements

In turbomachines, the flow total temperature determination requires probes that are not only robust and withstand high temperatures, but also able to correctly determine their fluctuations. To obtain accurate measurements, three dual thin-film probes based on a transient heat flux measurement technique have been constructed for time-averaged and time-resolved quantities. The design of the probes is first discussed. The probes, placed behind a cascade in the von Karman Institute (VKI) compression tube facility CT-2, are validated through a comparison with thermocouples. Measurements are also successfully performed behind the rotor and the second stator of the 1.5 stage high-speed turbine in the VKI compression tube facility CT-3. The comparison is made with a cold wire probe. The maximum-minimum temperature fluctuations measured behind the rotor and the second stator are 24 and 7degress, respectively.