A member-based porous method for predicting flow distortions around a lattice tower

Abstract

In the wind field measurement, the readings of an anemometer mounted on a lattice tower will be influenced by the tower. Therefore, evaluation of the flow distortions generated by a lattice tower is essential for correcting the wind speed data or guiding the arrangement of anemometers. Wall-refined CFD is a powerful tool to simulate the flow field but is quite time consuming for lattice structures. As an alternative approach for improving the computational efficiency of CFD, a member-based porous method was proposed by this article. It employs porous zones to substitute the real members of a lattice tower, so that the computational resources can be considerably saved. Wind tunnel test of two lattice tower segments were conducted to validate the member-based porous method. Models of wall-refined CFD were also established. Results of the member-based porous method are in acceptable agreement with those of test and wall-refined CFD. The method is proved to be an effective way to predict flow distortions of a lattice tower. Both the test and numerical simulations (wall-refined CFD and member-based porous) reveal that disparities exist between the flow field of different measurement planes. The results highlight the need to consider the impacts of member arrangement in predictions of the flow distortion. At last, some crucial issues on the flow distortion effects of a lattice tower were also discussed, results of the classic theoretical methods were compared with those of the member-based porous method.