Chapter 8, Problem 8.116P

Determine the tube diameter that corresponds to a $\text{1}0\%$ reduction in the convection heat transfer coefficient for thermal and momentum accommodation coefficients of ${\alpha }_t=0.92$ and ${\alpha }_p=0.89$ , respectively. Determine the channel spacing, a, that is associated with a $\text{1}0\%$ reduction in h using the same accommodation coefficients. The gas is air at $T=\text{ 35}0\text{ K}$ and atmospheric pressure for both the tube and the parallel plate configurations. The flow is laminar and fully developed with constant surface heat flux.