This Lloyd’s Register-GTC work involves implementing the Beddoes-Leishman model to simulate the unsteady airfoil effect (Fig. 1) and tests for a variety of airfoils using experimental data for airfoil pitching experiments. We compare the results of uBEM to direct rotor modelling simulations, for both static and moving rotor cases.
In the static simulations, research is required on the dynamic wake and skewed wake models to improve the accuracy of uBEM. For the moving rotor case (Figs. 2 & 3), based on the floating platform undergoing pitching motions, showed that uBEM was able to match the phase of the response and was more accurate than BEM. But, the inaccuracies from the static cases were evident here as well, thus work is needed to optimise the various corrective models.
On-going work is to study the various unsteady aerodynamic phenomena and model them accurately within uBEM. A hierarchy of simulation work has been introduced to reduce computational time and cost, while maintaining a high degree of accuracy. The simulations will be used to study and quantify the various unsteady aerodynamic phenomena, which will then be modelled in uBEM. Once the studies are completed, the uBEM code with the new corrective models will be validated for some Offshore Code Comparison (OC3) cases against direct rotor modelling simulations.
Our goal here is to study more unique aerodynamic features in greater detail, and develop more accurate tools for the unsteady aerodynamic analysis of floating offshore wind turbines.
- Abdulqadir Aziz Singapore Wala, Ng, E.Y.K, “Actuator disc modeling based on aerodynamic data extraction from direct rotor modeling of the NREL Phase VI turbine”, Progress in Computational Fluid Dynamics: An International Journal, Vol. 14, No. 6, Switzerland, (2013), Pp. 352–362.
- Abdulqadir Aziz Singapore Wala, Ng, E.Y.K, “Modeling of dynamic position of flow separation in Beddoes-Leishman model based on potential flow lift”, (in-press), 2016