TO THE CALCULATION OF ACOUSTIC FIELD CHARACTERISTICS FOR QUADCOPTER PROPELLERS

Abstract

The work defines the area of use of unmanned aerial vehicles (UAVs) of the type of quadrocopter and calculated the acoustic field of propellers in order to reduce the level of noise at some distance. The main sources of noise, which are the hubs of the quadrocopter, are considered. The first samples of UAVs appeared in the middle of the last century as a separate type of promising weapons, but now quadrocopter,began to be actively used in the civilian sphere. The theory of the sound field of the aircraft's air propeller, which was proposed by L. Gutin to simulate the noise from each of the chochire screws of the quadrocopter, was carried out. A mathematical model has been created for calculating the total acoustic field all the of quadrocopter screws. The analysis and the defined area of use of UAVs of type quadrocopter and the calculation of acoustic field of screws is given in order to reduce the noise level at some distance. The authors conducted an analytical review of the existing models of UAVs and quadrocopters, considered general examples of use of quadrocopters, their purpose and scope of application. On the basis of analytical review of constructions the fundamental scheme of quadrocopter for researches is given. The article is driven by the principal scheme of the chosen quadrocopter with the description of its main nodes. Based on the results of calculations, the noise distribution schedules of different frequencies in the space are constructed. The results from sound pressure levels for each of the five harmonics. Description of direction of acoustic fields on separate frequencies each of harmonics is constructed using the Besselyu function. Mathematical calculations have been performed in MathCad 2015. There are two forces on each screw element: thrust and resistance of the rotary motion. From the Basic Law of mechanics it follows that this element, in its turn, influences the environment with equal magnitude and opposable directed forces.