Research progress and considerations in the research of non-stationary turbulent characteristics of typhoon wind fields

The turbulent characteristics of typhoon wind fields has been a vital research focus in the field of structural wind engineering. Unlike the conventional boundary-layer wind fields, the typhoon is an exceptional wind field with extremely complicated non-stationary features that cannot be characterized by the parameters of statistically stationary wind fields. Based on the domestic and overseas achievements on long-term field measurements and accompanied analyses, this paper presents a review on the advances in the research of non-stationary turbulent characteristics of typhoon wind fields, aiming to summarize the approaches and models to characterize the non-stationary wind characteristics. Firstly, models for stationary and non-stationary wind speeds are reviewed, and the approaches to determine time-varying mean wind speeds are introduced. Secondly, advances in characterizing the turbulence intensity, turbulence integral length, evolutionary power spectral density, and time-varying coherence of non-stationary turbulence of typhoon wind fields are illustrated. Challenges in characterizing these statistics are emphatically discussed. Finally, problems that deserve a further in-depth research are proposed in allusion to the non-stationary characteristics of typhoon wind fields.