Calibration of a temperature dissipation probe in decaying grid turbulence

A four cold-wire probe, which allows all three components of the temperatur e dissipation rate epsilon(theta) to be measured, is "calibrated" in decayi ng grid turbulence, where (epsilon(theta)), the mean value of epsilon(theta ), can be determined accurately from the decay of the temperature variance (theta(2)). Th, probe yields values of the three components of (epsilon(the ta)) which are in reasonable agreement with local isotropy, in the range x( 1)/M less than or equal to 50. The pdfs and spectra of the three temperatur e derivatives also satisfy local isotropy reasonably well.