**2. Project concept**

Insufficient humidity and a low probability of the appearance of clouds suitable for sowing require an engineering solution to deliver to a given atmospheric horizon of cloud condensate, which will be sufficient for the formation of thunderclouds.

#### **Figure 1.**

*Average monthly temperature and humidity in the UAE by months in an annual cycle https://www.climatestotra vel.com/climate/united-arab-emirates.*

#### *Rain Tower DOI: http://dx.doi.org/10.5772/intechopen.112937*

The proposed methods of control using the "Rain Tower" and artificial intelligence will allow us to form a stable ascending vortex flow that can deliver to a given atmospheric horizon the moisture necessary for the formation of a thundercloud.

In our opinion, this is the only solution capable of delivering moisture, which is not enough for the formation of thunderclouds, to a given height. The design of the tower directs steam-saturated sea air from the coast from the intake manifold to the seawater evaporator. Then, after its additional enrichment with moisture, it enters the cloud droplet condenser. At the outlet of the moisture condenser, the air saturated with micro-drops is picked up by an ascending vortex flow.

A stable upward vortex flow is formed by the passive infrastructure of the topology of the lower part of the "Rain Tower". The pressure difference between the base of the tower and its upper cut creates a stable rarefaction and thrust in the body of the tower.

The shape of the "Rain Tower" is a two-focus hyperboloid of rotation that focuses the vortex flow into the working area of the aero-thermal power plant, where the wind turbine is located. The blades of this turbine have a special shape, due to the optimization of which the maximum coefficient of transformation of the rotational energy of the ascending vortex flow into the rotation of the electric generator is ensured. The electricity generated by the generator is used for life support and operation of all functional elements of the "Rain Tower" [2].

The movement of cloud micro-drops in a vortex flow is accompanied by their collision and enlargement. Coagulation of cloud droplets during their ascent to a given height maximally saturates the air with thunderstorm droplets, the size of which reaches that necessary for the formation of thunderstorm clouds and precipitation [3–5].

The vortex formation and coagulation control system is located behind the turbine of the vortex power plant on the inner surface of the duct in the upper part of the tower. This system contains special generators of ultrashort acoustic pulses, a system of phased arrays of ultra-wideband emitters that increase the coagulation rate of moisture droplets, prevent their drift to the axis of rotation, and control their radial movement in an ascending vortex flow.

Sequences of acoustic pulsed shock waves are generated by the AI of the control system while considering the environmental parameters. These sequences provide an effect on the coagulating droplets and the ascending vortex flow as a whole. Thanks to the control action, it is possible to set the pitch and speed of the rotational–translational movement of the ascending airflow, control the trajectory of large water droplets in the vortex body, and guarantee their growth to a given size at a given lifting height [6].

The control system for matching the vortex flow with the undisturbed atmosphere is located in the upper section of the Rain Tower. It forms a virtual air duct that ensures smooth evolution of boundary conditions during the interaction of the vortex with an undisturbed atmosphere. The virtual duct is formed by a sequence of concentric circular shock wave pulses that mimic the duct walls outside the Rain Tower housing.

The annular wave, like circles on water, expands, and as it spreads upward, the virtual duct turns into a diverging cone. As the shock wave attenuates, the walls of the virtual duct are eroded and a smooth alignment of the vortex flow with the undisturbed atmosphere is ensured.

Inside the virtual air duct, conditions are created for the propagation of short acoustic pulses that can affect coagulation processes outside the body of the Rain Tower. These influences prevent premature loss of moisture and guarantee its rise to the required height.

The friction of the vortex flow against the boundaries of the virtual air duct, together with the control acoustic action, completes the control of the process of raindrops coagulation and delivery of the thundercloud embryo to a given atmospheric horizon.

The appearance of a sufficient amount of moisture at the level of formation of thunderclouds (100–2500 m) will create the prerequisites for the growth of a thundercloud in natural conditions, and knowledge of the wind rose at a given horizon will make it possible to predict the time and place of rainfall [2, 7–10].
