ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
HEAT TRANSFER TO PULSATING, TURBULENT GAS FLOW
Resumo
Measurements of heat transfer parameters in pulsating and steady forced turbulent air flow through a vertical, circular tube, which was re-sistively heated, are reported. Inlet Reynolds numbers varied from 19,000 to 102,000; Mach numbers were 0.15 or below; pulsation frequencies ranged from 2.1 to 3.6 Hz and the peak-to-peak pressure fluctuations varied from 9 to 29 percent
of the mean pressure. At these conditions
the non-dimensional frequency α = r √(2nf/ν), varied from about 4 to 7 1/2; in laminar flow, quasi-steady approximations become weak when this frequency becomes greater than about two, but for
turbulent heat transfer in this Reynolds number
range the limitations are still to be determined.
Direct comparison between steady and pulsating
runs at the same values of the control parameters
essentially confirmed quasi-steady predictions
for Re> 5 × 104.