| Fanwing aircraft is a new concept of new aircraft,especially,its fan wing with unique aerodynamic characteristic.Analysis of fan wing aerodynamics relates to the air separation,cutting,rotation,distortion and other unsteady and nonlinear aerodynamic theory problems.Existing aircraft aerodynamics theories,such as momentum theory,blade element theory,vortex theory can't make the description and prediction well.In addition,there are many factors affecting the distributed thrust of fan wing and vortex lift,including geometric parameters,fan speed,relative position of fan and wing surface,parameters and shape of wing,size and direction of flow,causing great difficulties to the analysis of fan wing thrust,lift and control technology.In this paper,based on theoretical research,numerical simulation as the main method,test and validation as a means of research program,combining with the background of the demonstration project of fan wing aircraft in China,we will analyze aerodynamics principle,mechanism and control technology of thrust and lift force and other key issues of fan wing aircraft,and analyze and verify relevant aerodynamics the optimization scheme of fan wing aircraft to lay the foundation for the fan wing aircraft put into the practical stage.The details are as follows:(1)Aerodynamic characteristics numerical simulation research of fan wing aircraft: establishing suitable mathematical model(control equation),mesh generation method,boundary condition and initial condition,iteration method for fan wing principle research to make numerical calculation of fan wing vortex lift,distributed thrust and flow field and comparing with the experimental results.In addition,we built the control characteristic of leading edge and trailing edge flaps on the vane of fan wing aerodynamic force and found the suitable method of fan wing aircraft attitude control through the numerical algorithm.(2)Experiment on aerodynamic characteristics of fan wing aircraft: making a test model and device to study the principle of fan wing,measuring the lift,thrust,power and flow field through wind tunnel tests with appropriate measurement techniques and methods and analyzing the influence of cross flow fan speed,flow rate and angle of attack on the aerodynamic force of fan wing.(3)Theoretical study on aerodynamic characteristics of fan wing aircraft: according to the action form of fan wing on the flow field around,establishing the analysis model of aerodynamic force of fan wing aerodynamic characteristics based on momentum theory,comparing calculated results with experimental data to verify the research method.In addition,we revealed the mechanism of the vortex lift and the formation of the distributed thrust and discussed the experimental method of observing vortex formation through the experimental and numerical analysis of the flow field around the fan wing and the velocity of the flow field.(4)Study on Optimization of aerodynamic characteristics of fan wing aircraft: making research on the control of flow boundary layer on fan airfoil changing the fan wing basic geometric parameters by means of numerical simulation and experiment in order to further optimize the fan wing aerodynamic characteristics.In addition,the optimization effect of tandem fan wing on the dynamic characteristics of the gas are also studied,respectively analyzes the fan wing spacing,height,and installation angle parameters,and a wind tunnel experiment tandem wing fan.Through the above research,we obtained a set of suitable for numerical analysis of fan wing aerodynamic principle simulation method,established an analysis method for analysis of fan wing aerodynamic theory,revealed the mechanism of the vortex lift and the formation of the distributed thrust,proposed a visualization method of vortex formation,established the control method of the lifting force of the fan wing aircraft and gave the increasing drag reduction and layout method of fan wing in the practical application. |
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