Application Of Wind Field Fine Simulation In Low Level Wind Shear Alert System Layout

Low level wind shear is one of the most important weather phenomena in the world which is recognized as a great hazard to aviation safety. In order to prevent damage on flight caused by low-level wind shear, the Low-Level Wind Shear Alert System(LLWAS),with its reliable forecast accuracy, has been widely used in the United States as well as other countries and regions in the world. However, the system has rarely been applied in China mainland due to various objective reasons. In recent years, with the increasing domestic flight density, operations in most airport are suffered from low level wind shear much more seriously, which not only increases the workload of the operation related department, but also creates potential threats to flight safety. For these reasons, the development of the low level wind shear alert system of our own is becoming more and more urgent.For a complete set of low altitude wind shear alert systems, the prediction accuracy depends not only on the accuracy of the wind sensor, but also the reasonable layouts of wind sensor arrays. Due to the relevant technology of our own system is still not mature,the testing of the system had to depends on field operation,but with the result unknown.This may cause a waste of resources, so it is necessary to introduce computer simulation technology to aid the design of layout scheme.A mesoscale meteorological model, the Weather Research And Forecast model(WRF), was applied to high resolution wind field simulation, coupled with Computational Fluid Dynamics(CFD) software FLUENT. Lanzhou Zhongchuan airport was chosen as real case to set up a 3D wind field model. Then a series of simulation experiments are designed to verify the reliability and application of the model.First,an one-week lasting wind field simulating of area around Zhongchuan airport was conducted with both the simply WRF model and WRF-CFD coupled model. By comparing the results with the real datas, simulation by the coupled model was verified to be better.Then 8 typical wind shear events occurred in Zhongchuan airport in 2015 were simulated, and 5 of the simulation results had been detected with significant wind shear features. The coupling model was proved to be able to meet the requirements of wind shear simulation. And the wind shear occured in September 19 th was chosen as an example to analyze and discusse in detail.Finally, based on the fine simulated wind field model. An assessing method was designed to aid Low Level Wind Shear Alert System layout proposals assessment, which was then demonstrated with experiment.