University of Cambridge > Department of Engineering > Whittle Lab > Graham Pullan

CFD development

Vortex interaction The unsteady interaction of a streamwise vortex (red) with the endwall boundary layer, and secondary flow (blue), of the downstream blade row, from [5].

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.



[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.

Other Research at the Whittle Laboratory