Transition in Fluid Flows

Separated flows occur in an enormous range of important environmental, industrial and manufacturing processes. Improved models and a better understanding of separated flows will enable strategies to be developed to modify or control large-scale flow structures in turbulent flows. Downstream applications include: reduced pressure loadings for wind engineering, more efficient heat exchangers, reduction in forces on marine structures, drag and noise minimisation for automobiles, and improved two-phase fluid-particle models. For example, current computational studies of the mechanisms leading to turbulent wakes have shown that the route from smooth to turbulent flow is much less generic than previously thought, although appearing to involve the interaction of only a small number of different flow transitions. APAC support has allowed the stability characteristics of the wakes from different relevant generic body shapes to be mapped out and with some transitions interpreted in terms of simpler physical stability mechanisms. As another example, planned flow stability calculations for particles impacting with walls will determine the growth rates (for the transition from predominantly axisymmetric vortex rings to highly-diffusive three-dimensional flow) given relevant parameters. In turn, this will enable better two-phase models of particle-fluid interaction, and the augmentation of heat transfer from walls, to be developed. The computing time requested will strongly support the maintenance and further enhancement of active international collaborations with IRPHE (Marseille, France), Caltech (USA) and Cornell (USA). These collaborations benefit from complementary research skills that the Monash team supply in turn supported by access to the computational resources of APAC. An ARC international linkage proposal (2002-2003) directly supports the Monash IRPHE collaboration. In addition, this computing time request supports about six graduate students and a post-doctoral fellow, and will lead to ARC grant submissions and substantial publication output over the next year.

Principal Investigator

Mark Thompson
Mechanical Engineering Dept
Monash University

Project

d71

Co-Investigators

Hyeok Lee
Clement Roy
Keith Liow
Kris Ryan
Ivan McBean
Gregory Sheard
Shaun Johnson
Martin Griffith
Kerry Hourigan
Justin Leontini
John Sheridan
Aran Fitzgerald
Department of Mechanical Engineering
Monash University

RFCD Codes

240502, 291801

Significant Achievements, Anticipated Outcomes and Future Work

This project has been running for several years now and over that time a number of PhD students have used the resources of APAC to successfully complete their PhD research. Greg Sheard and Kris Ryan, who finished in 2004, went onto ARC postdoctoral fellows and are now staff in Mechanical Engineering at Monash. They published 6 Journal of Fluid Mechanics and 4 Physics of Fluids papers out of their PhD research. These are the top journals in their research areas. These outputs are strongly linked to access to APAC facilities. A number of other students have made important contributions over that time to the understanding of wake transition, fluid-structure interaction, flow stability, particle-wall interactions, vehicle aerodynamics, fluid mixing and vortex dynamics and interaction with walls (e.g., Craig Pregnalato, Shaun Johnson, Kenny Tan, Alex Cheung, Justin Leontini, Bronwyn Stewart, Aran Fitzgerald). While the FLAIR group at Monash is also moving into other areas such as bioengineering and microfluidics, and have specific APAC requests for these areas, the majority of the high impact journal articles over the last five years has come from investigations of flow stability, fluid-structure interaction, vortical flows and fully three-dimensional wake simulations.

Our collaborations with complementary international groups, especially IRPHE in Marseille, strongly benefits from the computational resources provided by APAC. This collaboration has resulted in three cotutelle (joint Australian-France supervised) PhD students joining the group since 2004. All these projects rely on high performance computing resources. I visited IRPHE in 2005, and Dr Lionel Schouveiler and Dr Thomas Leweke are spending six months and two months, respectively, at Monash in 2006 working on projects that rely on APAC input.

In 2006, we are moving into some new areas. These are: (i) modelling platelet interaction with blood vessel walls, which is relevant to plaque formation in the vessels; (ii) determination of flow stability for co-rotating trailing vortices, relevant to understanding trailing vortex dissipation for large passenger planes—this sets the minimum time between planes taking off at international airports; and (iii) modelling fluid, heat and chemical transport in microreactors used to grow cells. In addition, established research areas supported through this grant, such as fluid-structure interaction, fluid-mixing, understanding turbulent transition and particle-wall interaction will continue to produce high-quality journal papers.

 

Computational Techniques Used

The projects mostly used codes based on the spectral-element method.

In particular, there are three main variants

1 A two-dimensional (or axisymmetric) spectral-element code. This is not parallel but is used for parameter studies.

2 A two-dimensional (or axisymmetric) spectral-element code incorporating stability analysis for time-dependent and steady base flows. This code uses MPI to investigate the stability of several wavelengths at once. Parallel efficiency is high.

3 A three-dimensional spectral element code incorporating a Fourier expansion for the third dimension. The code is parallel and some effort was made to optimise this for MPI. (For example: arrays are converted to single precision for transport between nodes if possible, since interprocess communication is high. This parallel efficiency is good for a reasonable number of processors.

These codes are under constant development to incorporate new physics/models needed for new applications.

 

Publications, Awards and External Funding

External Funding and Awards

Current 2005-2007: K. Hourigan, W. Anderson, R. Evans, M. Thompson, K. Denton, M. Kawahashi, G. Sheard Fluid Dynamics of Circulation: Focus on the Kidney, ARC Discovery Grant
Current 2006-2007: Hourigan, K., Thompson, M.C., Anderson, W., Leweke, T., Schouveiler, L., Monkewitz, P.A., Brons, M., Sorensen, J.N.., Petersen, M., Sorensen, M.P., Fluid mechanics and physiology of blockages in vascular systems, ARC Linkage International LX0668992, requested $40k
Pending 2006-2008: W. Anderson,R. Evans,K. Denton,K. Hourigan,J. Bertram,H. Coleman,G. Fink,A. Fouras,B. Gardiner,I. Harper,R. Jagadeeshan, G. Karniadakis,S. Malpas,P. O’Connor,H. Parkington,J. Pearson,K. Ryan,G. Sheard,D. Smith, M. Thompson, G. Thouas, National Institute of Health (NIH) Exploratory Program in Systems Biology, $US1700k, Multidisciplinary modeling of renal vascular physiology
Pending 2007-2009: ARC Discovery, Novel micro-scale bioreactors to simulate and monitor physiological conditions for cells and tissues cultured in vitro for future biomedical applications, $641k, Hourigan, Trounsen, Thompson, Thouas, Leweke, Kawahashi.
Pending 2007-2009 NHMRC Project Grant 436898, Biomechanics of renal artery stenoses: functional consequences, W. Anderson, K. Hourigan, M. Thompson, G. Sheard

Publications

Publications generated with APAC support 2005-

1. Thompson, M.C., Hourigan, Ryan K. & Sheard, G.J., Wake transition of two-dimensional cylinders and axisymmetric bluff bodies, accepted (April 2006), Journal of Fluids and Structures (invited paper).
2. Leontini, J.S., Stewart, B.E., Thompson, M.C. & Hourigan, K., Predicting vortex-induced vibration from driven oscillation results, Applied Mathematical Modelling (in Press), 2006.
3. Leontini, J.S., Thompson, M.C. & Hourigan, K., The beginning of branching behaviour during vortex-induced vibration at 2-D Reynolds numbers, accepted October 2005, Journal of Fluids and Structures, 2006.
4. Thompson, M.C., Hourigan, K., Cheung, A. and Leweke, T., Hydrodynamics of a particle impact on a wall, accepted (April 2006), Applied Mathematical Modelling, 2006, 20 pages, (invited paper).
5. Fitzgerald, A.J., Hourigan, K. & Thompson, M.C., Vortex breakdown state selection as a meta-stable process, Journal of the Australian and New Zealand Industrial and Applied Mathematics Society, 46, C351--C364, 2005.
6. Griffith, M.D., Hourigan, K. & Thompson, M.C., Modelling blockage effects using a spectral element method, Journal of the Australian and New Zealand Industrial and Applied Mathematics Society, 46, C167--C180, 2005.
7. Leontini, J.S., Thompson, M.C. & Hourigan, K., Modelling vortex-induced vibration with driven oscillation, Journal of the Australian and New Zealand Industrial and Applied Mathematics Society, 46, C365--C378, 2005.
8. Liow, Y.S.K., Thompson, M.C. & Hourigan, K., Sound generated by a pair of axisymmetric viscous coaxial vortex rings, AIAA Journal, 43(2), 326-336, 2005.
9. McBean, I., Hourigan, K., Thompson, M.C. & Liu, F., Prediction of Flutter of Turbine Blades in a Transonic Annular Cascade, ASME Journal of Fluids Engineering, 127, 1053-1058.
10. Ryan, K, Thompson, M.C. & Hourigan, K.,Three-dimensional transition in the wake of elongated bluff bodies, Journal of Fluid Mechanics, 538, 1-29, 2005.
11. Ryan, K, Thompson, M.C. & Hourigan, K., Variation in the critical mass ratio of a freely oscillating cylinder as a function of Reynolds number, Physics of Fluids, 17(3), 038106-9, 2005.
12. Sheard, G.J., Hourigan, K. & Thompson, M.C., Computations of the drag coefficients for low-Reynolds-number flow past rings, Journal of Fluid Mechanics, 526, 257-275, 2005.
13. Sheard, G.J., Thompson, M.C. & Hourigan, K., The subharmonic mechanism of the Mode C instability, Physics of Fluids, 17(11), 111702, 2005.
14. Sheard, G.J., Thompson, M.C. & Hourigan, K., Computing the flow past a cylinder with hemispherical ends, Journal of the Australian and New Zealand Industrial and Applied Mathematics Society, 46, C1296-C1310, 2005.
15. Sheard, G.J., Thompson, M.C., Hourigan, K. & Leweke, T., The evolution of a subharmonic mode in a vortex street, Journal of Fluid Mechanics, 534, 23--38, 2005.
16. Stewart, B.S., Leontini, J., Hourigan, K. & Thompson, M.C., Vortex wake and energy transitions of an oscillating cylinder at low Reynolds number, Journal of the Australian and New Zealand Industrial and Applied Mathematics Society, 46, C181--C195, 2005.
17. Tan, B.T., Thompson, M.C. & Hourigan, K., Evaluating fluid forces on bluff bodies using partial velocity data, Journal of Fluids and Structures, 20(1), 5-24, 2005.
18. Thompson, M.C. & Hourigan, K., The shear layer instability of a circular cylinder wake, Physics of Fluids (Letters), 17(2) 021702-5, 2005.