DESIGN
Turbine design performed to ‘IEC 61400-2_013 Part 2 Small Wind Turbines’ requirements in regard to wind conditions, material requirements and safety factors. Turbine behaviour and loads modelled using in-house simulator (Cascade theory) and QBlade program (Lifting Line theory), taking into account dynamic stall, airflow curvature and turbulence effects.
In order to analyse turbine's performance and aerodynamic loads - a simulator based on Cascade Theory has been created.
The results from Axowind simulator a very close to the results produced by QBlade - a simulator program from Wind Energy Group of the Berlin Institute of Technology.
In the process of turbine design - Finite Element Method (PATRAN/NASTRAN) has been used, with all details of the turbine modeled.
As for the turbine itself - the generator was also modeled using FEM in order to calculate deflections and internal loads.
The stresses and strains in composite blade have been analysed as per IEC 61400-2 Part 2 "Small Wind Turbines".
The dynamic characteristics of the turbine have been calculated using a FEM model which also included custom-made tower. The scope of dynamic analysis included Normal Modes, Frequency Response and Rotor Dynamics (NASTRAN).
Campbell's diagram illustrates the normal modes which have been tuned to avoid resonance.