Nonlinear Sciences – Pattern Formation and Solitons
Scientific paper
2010-05-09
Phys.Rev.E82:036310,2010
Nonlinear Sciences
Pattern Formation and Solitons
33pages, 23figures, submitted to Physical Review E
Scientific paper
10.1103/PhysRevE.82.036310
We find three types of steady solutions and remarkable flow pattern transitions between them in a two-dimensional wavy-walled channel for low to moderate Reynolds (Re) and Weissenberg (Wi) numbers using direct numerical simulations with spectral element method. The solutions are called "convective", "transition", and "elastic" in ascending order of Wi. In the convective region in the Re-Wi parameter space, the convective effect and the pressure gradient balance on average. As Wi increases, the elastic effect becomes suddenly comparable and the first transition sets in. Through the transition, a separation vortex disappears and a jet flow induced close to the wall by the viscoelasticity moves into the bulk; The viscous drag significantly drops and the elastic wall friction rises sharply. This transition is caused by an elastic force in the streamwise direction due to the competition of the convective and elastic effects. In the transition region, the convective and elastic effects balance. When the elastic effect dominates the convective effect, the second transition occurs but it is relatively moderate. The second one seems to be governed by so-called Weissenberg effect. These transitions are not sensitive to driving forces. By the scaling analysis, it is shown that the stress component is proportional to the Reynolds number on the boundary of the first transition in the Re-Wi space. This scaling coincides well with the numerical result.
No associations
LandOfFree
Flow pattern transition accompanied with sudden growth of flow resistance in two-dimensional curvilinear viscoelastic flows does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Flow pattern transition accompanied with sudden growth of flow resistance in two-dimensional curvilinear viscoelastic flows, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flow pattern transition accompanied with sudden growth of flow resistance in two-dimensional curvilinear viscoelastic flows will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-611912