Liu, Yao-Hsien (2005-08). Effect of rib spacing on heat transfer and friction in a rotating two-pass rectangular (AR=1:2) channel. Master's Thesis. Thesis uri icon


  • The research focuses on testing the heat transfer enhancement in a channel for
    different spacing of the rib turbulators. Those ribs are put on the surface in the two pass
    rectangular channel with an aspect ratio of AR=1:2. The cross section of the rib is
    1.59 x 1.59 mm. Those ribs are put on the leading and trailing walls of the channel with
    the angle of flow attack to the mainstream of 45????. The rotating speed is fixed at 550-RPM
    with the channel orientation at ????=90????. Air is used as the coolant through the cooling
    passage with the coolant-to-wall density ratio ( ???? ???? ?????? ) maintained around 0.115 in the
    first pass and 0.08 in the second pass. The Reynolds numbers are controlled at 5000,
    10000, 25000, and 40000. The rib spacing-to-height ratios (P/e) are 3, 5, 7.5, and 10. The
    heat transfer coefficient and friction factor are measured to determine the effect of the
    different rib distributions. Stationary cases and rotational cases are examined and
    compared. The result shows that the highest thermal performance is P/e=5 for the
    stationary case and P/e=7.5 for the rotating case.

publication date

  • August 2005