Title: LINEAR STABILITY NORMAL MODE ANALYSIS OF VISCOELASTIC FLUID FLOWS
1LINEAR STABILITY (NORMAL MODE) ANALYSIS OF
VISCOELASTIC FLUID FLOWS
- Mehmet SAHIN Helen J. WILSON
- Department of Mathematics, UCL
- Gower Street, London, WC1E 6BT, UK
- 21-22 September 2006
2Computed Base Flow for Periodic Array of Half
Cylinders Placed on Channel Walls at We2.8.
H4R and L2.5R
Principle stress difference
u-velocity
3Linear Stability (Normal Mode) Analysis
Base Flow Leading Eigenfunction
Three-dimensional streamtraces
4Computed Leading Eigenfunction
Txx (Anti-symmetric)
w-velocity (Anti-symmetric)
5Computational Unstructured Mesh for Experimental
818 Contraction-Expansion Case
6Computed Base Flow for Rolie-Poly Fluid with
?0.1, We55 and We_R1.1.
u-velocity
Principle stress difference
7Linear Stability (Normal Mode) Analysis
8Conclusions
- A parallel adaptive unstructured normal mode
analysis code has been developed to investigate
flow instabilities for both Oldroyd-B and
Rolie-Poly fluids. - The accuracy of the code is verified for the
Oldroyd-B fluid past periodic array of
cylinders. - The code may need to be modified for the
multi-mode version of Rolie-Poly equations. - More accurate experimental values are recently
become available for the Rolie-Ploy fluid in the
818 experimental contraction expansion case. - More work is needed for the efficient solution of
Stokes problem in 3D in order to simulate 3D flow
instabilities.