Nomenclature

a streamwise extent of test surface b spanwise extent of test surface

Dh channel hydraulic diameter e rib turbulator width e' rib turbulator width in streamwise direction f friction factor fo baseline friction factor in a smooth channel with no rib turbulators

H channel height h heat transfer coefficient based on flat projected area, q"/(Tw -Tm)

k thermal conductivity l coordinate in direction parallel to ribs

Nu local Nusselt number, hDh / k

Nuo baseline Nusselt number in a smooth channel with no rib turbulators p streamwise pitch spacing of rib turbulators

P time-averaged local static pressure

Pr Prandtl number q" surface heat flux

ReH Reynolds number based on channel height

ReDh Reynolds number based on hydraulic diameter t time t * non-dimensional time, tU/ H

T local static temperature

U streamwise bulk velocity averaged over the channel cross section u time-averaged local streamwise velocity

W coordinate in direction normal to ribs x streamwise coordinate measured from the test section inlet

Y normal coordinate measured from the test surface between the ribs z spanwise coordinate measured from the test surface centerline a x streamwise vorticity

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