粘弾性流体の抵抗低減乱流境界層の直接数値シミュレーション

第2報, エネルギー輸送および組織構造

抄録

Energy transfer and turbulence structures in a zero-pressure gradient turbulent boundary layer of a drag-reducing viscoelastic solution were investigated using the direct numerical simulation (DNS) data with the Oldroyd-B and Giesekus models. This work is an extension of the first report, in which mean velocity profiles and turbulence statistics have been investigated. It is found that the contribution to turbulent kinetic energy transfer due to the polymer stress work term is not negligible for the Oldroyd-B model, whereas it is negligible for the Giesekus model. The polymer diffusion term for both the Oldroyd-B and Giesekus models is negligible. For the Oldroyd-B model, we can see that quasi-streamwise vortices are weakened and become larger in the streamwise direction, compared to Newtonian fluids. On the other hand, quasi-streamwise vortices for the Giesekus model are similar to those for Newtonian fluid.