The roller for seeds of different sizes, a variable-size pneumatic cylinder precision seed metering device was designed, which could realize the precision seeding of different diameter seeds without changing the roller. The structure and working principle of seed metering device were explained, and the structural parameters of the main components of the seed meter were determined. The ANSYS was used to analyse the influence of the size of the negative pressure inlet pipe and the shape of the eyelet on the airflow velocity in a negative pressure chamber. Based on the above optimal structure, the orthogonal experiment of seed metering device was carried out. Testing results showed: under the negative pressure of 4 kPa, roller speed of 16.93r/min and the wind speed of 11.48m/s, the seed metering device had the best seeding effect. The qualification rate of the seed metering device was 92.37%, the miss-seeding rate was 3.74% and the over-seeding rate was 3.88%.

In order to improve the aerodynamic characteristics by increasing the energy of the wind flow of wind turbines with a vertical rotational axis, a special device - wind flow concentrator was proposed. The concentrator contains channels with a curved contour, which are installed around the rotor. To study the hydrodynamic parameters of the wind flows concentrator depending on the ratio between the input and output geometric characteristics of the channels, as well as the angles of entry and exit methods of mathematical modeling are used. Based on the method of quadratic rotational design of orthogonal combinations, using three-dimensional numerical simulation, the aerodynamic characteristics of the wind flow concentrator for a vertical axis wind turbine were investigated.