Airfoil design and testing
Our group has created an outstanding platform to perform simulations of bluff bodies. As a proof of that, consider the simulations of flow around sphere [1], flow around cylinder [2], as well as the DNS and LES simulations of airfoils from families NACA [3][4], DU [5] and FX [5].
The key elements that makes our code capable to simulate at that level are mainly these two:
- The great speed-up till thousands of CPUs
- The numerical schemes used to conserve painstakingly the turbulent kinetic energy
We are now developing a new approach for these cases: a self-adaptative mesh. This approach consist mainly in setting up a structured mesh that will auto-refine itself (iteration after iteration) in order to increase density of nodes in the more demanding areas while reducing in the less demanding ones.
References
[1] Rodríguez, I., Lehmkuhl, O., Borrell, R., & Oliva, A. (2013). Flow dynamics in the turbulent wake of a sphere at sub-critical Reynolds numbers. Computers & Fluids, 80, 233–243
[2]O. Lehmkuhl, I. Rodríguez, J. Chiva and R. Borrel. On the large eddy simulations of the flow past a cylinder at critical Reynolds numbers. In Direct and Large-Eddy simulations (DLES9). Dresden. 2013
[3] I. Rodríguez, O. Lhmkuhl, R. Borrell, A. Oliva. “Direct numerical simulation of a NACA0012 in a full stall”. International Journal of Heat and Fluid Flow, Volume 43, 194-203, 2013.
[4] Lehmkuhl, O. et al. On the large-eddy simulations for the flow around aerodynamic profiles using unstructured grids. “Computers and fluids”, Setembre 2013, vol. 84, p. 176-189
[5]J. Calafell, O. Lehmkuhl, I. Rodríguez, A. Oliva. “On the Large-Eddy Simulation modelling of wind turbine dedicated airfoils at high Reynolds numbers”. 7th International Symposium on Turbulence, Heat and Mass Transfer. September 24-27, Palermo, Sicily, Italy.