Heat transfer to pulsating, turbulent gas flow

Pulsating and steady forced turbulent air flow through a vertical circular tube which is resistively heated is subjected to heat transfer parameter measurements over the 19,000-102,000 Reynolds number range, at Mach numbers lower than 0.15. The pulsation frequencies ranged over 2.1-3.6 Hz, while the peak-to-peak pressure fluctuations varied over 9-29 percent of the mean pressure. The nondimensional frequency alpha varied under these conditions from 4.0 to 7.5. Direct comparison between steady and pulsating runs at the same control parameter values has confirmed quasi-steady predictions for Reynolds numbers greater than 50,000.