Pages 7-8
Momentum and thermal turbulence structures in a channel flow have been investigated through DNS database up to Re_γ=640,where Re_γ is the Reynolds number based on the friction velocity u_γ and the channel half width δ. It was found that large-scale motions exist in the outer layer at high Reynolds numbers for both momentum and thermal fields. It was shown that the near-wall turbulence structures become clustered with increasing Reynolds number for both momentum and thermal fields. It was also shown that large-scale structures exist even in the near-wall region at high Reynolds number, which is closely associated with the large-scale motions in the outer layer.