Numerical Study of Thermal Behavior of a Wind Turbine Nacelle Operating in a Nordic Climate

Abstract

This article presents a numerical method for investigating the thermal behavior of a wind turbine nacelle operating in a Nordic climate. External air flow around the nacelle and rotor as well as internal air flow through the nacelle are described using the Reynolds-averaged Navier-Stokes equations. The energy equation is used to account for heat transfer effects. The standard k − ε model is chosen for the closure of time-averaged turbulent flow equations. The rotor is modeled using the actuator-disk concept. An unstructured control-volume finite-element method is employed to solve the resulting governing equations. This article focuses on the effects of external air temperature, wind velocity, and the heat rate released by an electrical generator on the spatial distribution of the temperature inside the nacelle. It is found that, to maintain an acceptable temperature level within the nacelle during summer, the amount of air mass rate flowing through the nacelle should be adjusted properly as a function of wind velocity and external temperature. During winter, the nacelle should be well insulated and the air should be well stirred to obtain nearly uniform temperature distribution within the nacelle.

Acknowledgments

This study received support from the Canada Research Chair Program. Support from the Natural Sciences and Engineering Research Council of Canada (NSERC) in the form of research grants is gratefully acknowledged.