Research On The Transient Aerodynamic Problem Of HAWT And Software Integration

The transient aerodynamic problems is the main research object of present wind turbine analysis and design technology, and also is one of the kernel problems to be resolved in the national "863 Plan" project "Full System Loads Analysis and Optimization Design of Wind Turbine Software". This paper presents a numerical algorism of aerodynamic analysis and dynamic loads calculation for the horizontal axis wind turbine (HAWT). An aerodynamic analysis and dynamic loads calculation model for HAWT is developed. Based on these, with the technology of COM and tool of Visual C++ the program which realizes the numerical algorism is integrated with the CAD software "Blade Design for windows". This paper includes four sections: aerodynamic analysis and calculation, turbulent wind field model, dynamic stall model, develop software with COM.The aerodynamic analysis and calculation section first discusses the traditional analysis and calculation theory. Based on the traditional theory the aerodynamic analysis and dynamic loads calculation model is developed. The dynamic loads calculation model calculates the wind velocity with time series and aerodynamic force coefficient of airfoil with turbulent wind field model and dynamic stall model. It breaks the restriction of the traditional theory which only supports stationary calculation.Based on the Taylor rigidity turbulent hypothesis, the turbulent wind field model takes the modified von Karman model in boundary layer near ground of the power spectral densities of turbulence fluctuation velocity wind to obtain the cross spectral densities of turbulence fluctuation between two points in the wind field. The three-dimensional structure in space and time of the turbulence can therefore be obtained on foundation of the turbulence intensity. It provides convenience for the dynamic performance analysis of wind turbine in the turbulent wind field.The dynamic stall model is based on the Beddoes-Leishman model which evolves from the helicopter theory. The correction for wind turbine is researched and the method to obtain the time constants correlative with the separation point and the influence of the aerodynamic coefficient to the calculation result is investigated from there aspects of theory analysis , implement method and wind tunnel experiment result. The model built inAbstractthis paper can be brought easily into the momentum and strip theory system and provides an efficient way for dynamic stall theory to be applied in engineering field.The software is designed with Object Oriented Programming (OOP) and the technology of COM (Component Object Model). The calculation program is encapsulated into COM objects to integrate with the CAD software "Blade Design for windows". The COM objects extend the functions of "Blade Design for windows" efficiently.