# CFD development

CFD is a vital tool in the aerodynamic design of turbomachines. Since CFD's introduction over 30 years ago, there has always been a trade-off between the fidelity of the modelling and the run-time required for the calculation. My CFD research is focussed on improving the capabilities of CFD so that more features of the real flow can be captured during a routine design process. For example, the time required for an unsteady calculation (to resolve blade row interaction) is often prohibitive, but dual time-stepping can achieve a 10x speedup [7] and resolve flow structures not present in steady calculations, [6].

Over the past 10 years, parallel hardware has become affordable. This
creates many challenges for the software developer. Both *externally*
parallel hardware (distributed memory PC clusters, MPI [5]) and
*internally* parallel hardare (multi-core CPUs, many-core GPUs [1-4])
are available.

### Links

- Cambridge Many-Core Group
- Presentation at the MUSAF Colloqium Toulouse (Sep 2010)
- Presentation at the 1st UK CUDA Developers' Conference Oxford (Dec 2009)
- CFD case study presentation given at the NVIDIA CUDA Tutorial, ISC June 2009
- Lecture given at the University of Cagliari, Sardinia, March 2009
- A presentation introducing GPGPU, this one with CUDA code snippets (May 2008)
- BBC report on our GPU research (Nov 2007)
- www.gpgpu.org - a useful GPU programming resource site
- Specs of GPU machines that we have used

## Publications

[1] Brandvik, T. and Pullan, G. (2009) An Accelerated 3D Navier-Stokes Solver for Flows in Turbomachines. Presented at ASME Turbo Expo, Orlando, FL, June 2009.

[2] Brandvik, T. and Pullan, G. (2008) Acceleration of a 3D Euler Solver using Commodity Graphics Hardware. Presented at the 46th AIAA Aerospace Sciences Meeting, Reno, NV, Jan 2008. draft

[3] Brandvik, T. and Pullan, G. (2007) Acceleration of a two-dimensional Euler solver using commodity graphics hardware. IMechE, Journal of Mechanical Engineering Science, 221/C12. draft

[4] Brandvik, T. and Pullan, G. (2007) Acceleration of a 2D Euler solver using graphics hardware. Cambridge University Engineerng Dept Technical Report, CUED/A-TURBO/TR.132.

[5] Rosic, B. and Denton, J.D. and Pullan, G. (2006) The importance of shroud leakage modelling in multistage turbine flow calculations. Transactions of ASME, Journal of Turbomachinery, 128 (4). pp. 699-707.

[6] Pullan, G. (2006) Secondary flows caused by blade row interaction in a turbine stage. ASME Transactions, Journal of Turbomachinery, 128 (3). pp. 484-491.

[7] Pullan, G. and Denton, J.D. (2003) Numerical simulations of vortex-turbine blade interaction. In: 5th European Turbomachinery Conference, 7-11 March 2003, Prague, Czech Republic.