A theoretical study is performed to investigate transport phenomena in chan
nel flows tender uniform heating from either both side walls or a single si
de. The anisotropic t(2) - Et heat-transfer model is employed to determine
thermal eddy diffusivity. The governing boundary-layer equations are discre
tized by means of a control volume finite-difference technique and numerica
lly solved using a marching Procedure. It is found that tinder strong heati
ng from both walls, laminarization occurs as in the circular tube flow case
; during the laminarization process, both the velocity and temperature grad
ients in the vicinity of the heated walls decrease along the flow resulting
in a substantial attenuation in both the turbulent kinetic energy and the
temperature variance over the entire channel cross section; both decrease c
auses a deterioration in heat transfer performance; and in contrast, lamina
rization is suppressed in the Presence of one-side-heating, because turbule
nt kinetic energy is produced in the vicinity of the other insulated wall.