A linear wake expansion function for the double‐Gaussian analytical wake model

The double‐Gaussian (DG) approach for analytical wake modeling leads to abetter understanding of the wake transition mechanism within a full‐wakeregion behind a non‐yawed horizontal‐axis wind turbine (HAWT). To date, akey parameter of the wake expansion in the DG model still has yet to bedefined explicitly instead of tuning, thus limiting its usability for practicalapplications. The present work aims to overcome this limitation by proposinga simple linear wake expansion function for the DG model constructed fromthe existing parameters based on the conservation of mass and momentum.Considering the physical and statistical approaches, the proposed function isspecifically intended to approximate the wake expansion downstream of anon‐yawed HAWT under turbulence inflow. Seven case studies from windtunnel measurements and large eddy simulations under different inflowconditions were used to examine the effectiveness of the proposed function. Ingeneral, the evaluation results in the present study show the effectiveness ofthe proposed expansion function for the DG wake model to predict the wakeexpansion and its recovery behind a non‐yawed HAWT without a prioradjustment or tuning of the wake expansion parameter