What is the influence of downforce wind field of eppo uav on operation?

It is often heard that the downforce wind of eppo uav plays a good role in spraying operation, making the penetration of pesticide spray stronger.So what is this high-sounding "downwind"? 

What is downwind? 

The downforce wind of eppo uav comes from its propeller and the vortex airflow formed by high-speed rotation (the vortex airflow and the airflow on the eppo uav form a pressure difference, which provides lift for its hovering and flying). 

When operating, unmanned aerial vehicles (uavs) are generally 1.5 to 10 meters away from crops, depending on the type of crops.At this time, the medicine sprayed from the uav is like fog. The particles are very small and will drift with the wind. It is not easy to spray on the crops, let alone the root parts of the crops.At this time, the downforce wind field of the uav plays a great role. The downforce wind field combined with the high-pressure nozzle can make the spray penetration stronger, reduce the drift of the liquid, and achieve the effect of deep spraying and uniform coverage. 

That is to say, the liquid medicine is sprayed by the nozzle of the uav, and the downward wind from the blade makes the droplets on the crops more medicinal, which plays a good prevention and control role. 

Wind and fog synchronization rate

The wind-fog synchronization rate means the probability that the downforce wind and fog particles reach the crop canopy at the same time.The "wind-fog synchronization rate" aims to study the complex mutual movement between downforce wind and fog particles of eppo uav. 

Generally speaking, there are three scenarios for the distribution of aerosols in the air:

(1) when the nozzle layout of the plant protection uav is not directly below the rotation radius of the propeller, the fog particles will show a serious uptrend. 

(2) whether the plant protection uav adopts centrifugal or pressure nozzle, the flying speed and flying height of the uav above the crops will vary, and sometimes the wind and fog may not reach the crop canopy at the same time. 

(3) when the plant protection uav is hovering, the downforce wind is the largest, which causes the crops to sway greatly and strongly from the roots. In the flight, only the canopy branches and leaves of the crops sway. 

The ideal scenario for now is the third scenario mentioned above: hover.On the whole, when the flying speed of eppo uav is too fast and the altitude is too high, the wind field will be significantly lagged behind when the fog particles reach the crop canopy.

Therefore, the downforce wind of the plant protection uav is its own property, and the wind field can cause irregular oscillation of crops. For the plant protection scenario with higher requirements on penetration, a reasonable flight operation mode should be adopted to determine whether spraying is an advantage, and its "wind-fog synchronization rate" and optimized spraying system should be further studied. 

In addition, the spraying effect is also related to the sprinkler head. Currently, there are two types of sprinkler heads, fan type and centrifugal type. The pressure sprinkler head itself has downward pressure.While the centrifugal nozzle spray effect is good, but the nozzle itself does not pressurize the effect.