1. An efficient inflow generation for large-eddy simulation of wind/tide turbine flows Zheng-Tong Xie (AFM group, FEE)

2. Questions and approaches Why turbulence? Why bother to use LES and to develop inflow generation method? (LES for large separation, peak loading, providing parameterisation) Current inflow approaches - inefficient, divergence-free not considered (e.g. inlet velocities does not satisfy continuity eq). Why divergence-free required? (when peak loading, acoustic issues are of interest). We developed a simple and efficient inflow generation –500 times faster than the old ones; artificial p flucts. significantly reduced. Applications: wind turbine flows, ventilation in large buildings, heat transfer at building surfaces.

3. Spanwise-component of vorticity at mid-span of a NACA0006 blade at α =7˚, Re =50,000 (Kim, Xie, Castro 2011) Laminar inlet Turbulent inlet, TI=8% LES of flows around a static wind-turbine blade

4. Pressure fluctuations at x/  =30 Divergence free inflow conditions for a plane channel flow О~10 3 reduced! Ref data (Kim, Xie, Castro 2012) Div. non-freeDiv. free