HEAT MASS TRANSFER IN A ROTATING 2-PASS CHANNEL WITH TRANSVERSE RIBS/

Naphthalene sublimation experiments have been conducted to study the l ocal heat/mass transfer distributions on the rib-roughened leading and trailing walls of a rotating, two-pass, square channel, that models i nternal turbine blade cooling passages, The height of the transverse r ibs was equal to one-tenth the spacing between the ribs, which was the same as the hydraulic diameter of the test channel, The Reynolds numb er and rotation number ranged up to 1 X 10(4) and 0.24, respectively. The results showed that, for radial outward now in the first pass, the re was very little spanwise variation of the local heat/mass transfer between consecutive ribs on the trailing wail, When the rotation numbe r was high, however, there was significant spanwise variation on the l eading wall, with high heat/mass transfer in the middle of the wall an d very low heat/mass transfer near the two side walls. For radial inwa rd flow in the second pass, the sharp turn reduced the difference betw een the heat/mass transfer on the leading wall and that on the trailin g wall. The sharp turn also caused spanwise asymmetric variation of th e local heat/mass transfer between consecutive ribs in the second pass immediately downstream of the turn, Relative to the heat/mass transfe r in a corresponding stationary channel, the overall heat/mass transfe r in a rotating channel with rib-roughened walls was not affected by t he Coriolis force as much as that in a rotating channel with smooth wa lls.