Pultrusion of a vertical axis wind turbine blade part-I: 3D thermo-chemical process simulation

A novel three dimensional thermo-chemical simulation of the pultrusion process is presented. A simulation is performed for the pultrusion of a NACA0018 blade profile having a curved geometry, as a part of the DeepWind project. The finite element/nodal control volume (FE/NCV) technique is used. First, a pultrusion simulation of a U-shaped composite profile is performed to validate the model and it is found that the obtained cure degree profiles match with those given in the literature. Subsequently, the pultrusion process simulation of the NACA0018 profile is performed. The evolutions of the temperature and cure degree distributions are predicted inside the heating die and in the post-die region where convective cooling prevails. The effects of varying process conditions on the part quality are investigated for two different heater configurations and with three different pulling speeds. Larger through-thickness gradients are obtained for the temperature and degree of cure as the pulling speed increases. This will affect the process induced residual stresses and distortions during manufacturing.