Numerical Simulation Of Three-cup Anemometer’s Aerodynamics Characteristics Based On CFD And Structure Optimization Design

Three-cup anemometer is widely used to measure wind speed because of its linear relationship between rotation speed and wind speed, large measuring range and low cost. Also, more and more applications put forward stringent requirement on its performance. C urrent studies on cup anemometer at home and abroad mainly depend on the theoretical analysis and wind tunnel experiments. However, the first method contains a large number of simplified assumptions and the second mentioned way costs a lot of time and money, which lead to ambiguity on the relationship between anemometer’s structure parameters and aerodynamic performance s. The application of computational fluid dynamics in the field of fluid flow provides an effective way to research the aerodynamic performances and structure optimization design of three-cup anemometer.The research content of this article is aimed at studying the three-cup anemometer’s aerodynamic characteristics through numerical simulation combined with theoretical analysis and wind tunnel experiment to verify the reliability of the simulation results, which provides a new way to guide the structure optimization design of the three-cup anemometer. The main content includes:(1) Expounding the anemometer’s dynamic, static characteristics theory through setting up the aerodynamic motion model and introducing the basic theory of CFD, which lays the foundation of the following researches;(2) Adopting the numerical simulation model to research the wind cup’s air resistance characteristics combined with detailed introduction of the process of steady numerical simulation and experimental comparison, which provides a reference for cup optimization;(3) In order to simulate the anemometer’s passive response motion by CFX, an unsteady numerical simulation scheme based on Transient Rotor-Stator model, Simo Wong arithmetic and RNG k-e turbulent model is proposed, then comparing with the aerodynamic parameters resulting from the simulation results with the theory analysis and wind tunnel experimental data. Research shows that the numerical simulation method can accurately predict the dynamic response process and the linear characteristic of three-cup anemometer and the calculation error is less than 20%;(4) Linear characteristic of cup anemometer, respectively, starting performance and fast dynamic response is studied by using the methods of CFD numerical simulations, approximate models and prediction optimizations, and the influences of radius of gyration and cup diameter on constant distance and linear coefficient are summarized. The starting performances of different cups are analyzed, and the structural optimization design of improving the dynamic performances of anemometers is proposed. The results show that the linear coefficient increases linearly with the increasement of gyration radius, decreases with the increase ment of cup diameter, of which the gyration radius is the main influence factor; The starting performance of hemispherical cup is superior to that of cone cups, and there is little difference on starting performance in a variety of cups with different cone angle; The aerodynamic performance of the three-cup anemometer with the 84 mm of gyration radius and 70 mm of cup diameter can improve significantly.