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 Martina Cracco

Martina Cracco

Research student, School of Mathematics

Room M/2.30, 21-23 Senghennydd Road, Cathays, Cardiff, CF24 4AG


Research Group

Applied Mathematics

Research Interests

Computational Fluid Dynamics, viscoelasticity, non-Newtonian fluids, boundary layers, hydrodynamics stability theory, bypass transition, numerical methods


Research interests

The aim of my research project is to improve the understanding of the stability behaviour of non-Newtonian fluids in boundary layers.

In the first part of my PhD I considered a flow of a second grade fluid over a wedge. A first look at the 2D linear stability analysis suggests that non-Newtonian effects tend to delay the instability. Three-dimensional perturbations cannot be ignored for non-Newtonian fluids because Squire's theorem is not proven in general. In fact, I showed that elasticity in this model tends to destabilise disturbances that are highly three-dimensional. Moreover, the non-Newtonian effects in this model increase the growth of energy over short periods of time. This approach is called bypass transition analysis and gives a more complete insight of the linear stability than the eigenmode analyis.

Currently I am working on the bypass transition of a more complex viscoelastic model, that is Oldroyd B.



  • MATHS support
  • Foundations of Mathematics II tutorials
  • Linear algebra I tutorials


  • MATHS support


Stability Analysis of non-Newtonian Fluids in Boundary Layers

Funding source



Tim Phillips photograph

Professor Tim Phillips

Head of School, Mathematics

Areas of expertise