Analytical Methods And Experimental Research Of Micro-rotor Aerodynamic Characteristics

Due to the special flight performance and potential applications of a micro-rotor aircraft, its importance has been increasingly recognized by both military and civilian sectors of all countries and scientific researchers. However, due to the strict restrictions on size, weight and endurance time, many technical problems have to be solved for development of micro-rotor. Among the technological bottlenecks, aerodynamics of micro-rotor is the most fundamental one, and is also one of the hotspots that arouse wide concern. As the lifting surfaces and control surface of a micro-rotor aircraft, aerodynamic performance of the micro-rotor directly affect the performance, controllability and the efficiency of the aircraft, and is of much importance to accurately predict the aerodynamic characteristics of micro-rotor. This paper studied the aerodynamic characteristics of the rotor airfoil and blade at a low Reynolds number systematically with experimental, theoretical calculations as well as CFD simulation technology and other methods, and has developed a set of analytic techniques to calculate and analyze the aerodynamic characteristic of a micro-rotor aircraft.The calculation of airfoil low Reynolds number aerodynamic characteristics is the foundation of micro-rotor aircraft aerodynamic characteristic calculation. In the first place, he paper set up the CFD method to calculate the airfoil aerodynamic characteristic at low Reynolds number, calculated and analyzed the airfoil aerodynamic characteristic under a low Reynolds number condition, and conducted a comparative analysis of the impact of thin arc airfoil's geometric characteristics on the aerodynamic characteristics. The airfoil was suitable for the micro-rotor aircraft. In the next place, the paper established the method to calculate the micro-blade aerodynamic characteristic under hover flight condition with blade-element momentum theory in combination with airfoil aerodynamic characteristics of micro-rotor blades at low Reynolds number. After that the paper designed the equipment to test the micro-blade hover performance, determined the aerodynamic characteristics of micro-blade while hovering and completed the experimental verification of the calculation method. In the last place, the paper simulated the 3D flow field of micro-rotor hover flight with CFD technique.The micro-blade aerodynamic characteristic calculation model in this paper is verified to be reliable after comparison of the calculation result and the test result. The method established in this paper for analyzing the micro-blade aerodynamic characteristic, with the advantage of simplicity and high accuracy, is convenient for engineering application and has provided a theoretical basis for efficient designing o micro-blade in the future.