Technology

Anti-hail Station

 
The operation of anti-hail station is based on the influence of vertically spreading high powered shock waves on the atmosphere. The field of vertically aligned shock

waves has an effect on the thunderstorm cloud structure negating the possible conditions for hail formation. This method of affecting thunderstorm clouds was patented and presented in the beginning of the past century
 (USA Patent 684030, 1901)
From a technical standpoint, the above mentioned method is conducted in the following way. Generation of sound shock waves of necessary power and up to 300 m/s speed takes place in “acoustic cannons” as a result of periodic explosions of a gas with high energetic properties. In case of a proper selection of the gas material and its quantity the acoustic cannon ensures the sufficient power to affect the structure of thunderstorm clouds at heights up to 10 km. “Shots” are performed once every 6-8 seconds. As a result the precipitation in the form of hail is prevented and substituted with rain, wet snow or safe small ice particles. The shock waves from periodic explosions are aligned to the sky via a conic tube. The conic shape ensures the necessary power and alignment of the shock waves. Acetylene, MAF gas, a special mix of propane and butane etc. 
The stations are placed at a certain distance from communication and power sources. For their autonomous and  long-range operation solar panel power system and remote control system (including modem of radio or mobile communication and using a special software) are used.
Zenith® anti-hail station utilizes a number of technical and technological original solutions, optimal diameter and geometric parameters of conic cannon were calculated, necessary operation modes (quantity of explosive material, refill time, periodicity of fuse operation) were developed, modified gas distribution system and highly effective and reliable remote control system were created (A. Vardanyan. RA Patent, N389U).


For autonomous operation (without on-site service personnel) of Zenith® anti-hail station solar panel power system and remote control GSM mobile communication system are used. Special software for station launch and operation was developed which allows activating station’s cannon with 6 second periodic shots via computer or GSM mobile communication system (via SMS messages).
Combined Rain Stimulation System

Recent years extensive researches were conducted in many countries connected with global warming and resulting worldwide climate change to introduce effective artificial precipitation stimulation technologies.

In the context of precipitation stimulation, various research and investigations conducted in former Soviet Union. Negative ion emission method found to be an effective method to stimulate precipitations in local area. The idea was that an efficient negative ion emitter from a near-to-Earth surface could influence the atmospheric processes, particularly decrease air temperature in the local area and hence stimulate condensation of water droplets within the clouds and hence stimulate atmospheric precipitations. Various successful laboratory experiments were conducted in support of this idea.

Needless to mention that these technologies are ecologically clean, as they don’t use any chemical reagents for operation. These methods are essentially different from traditional cloud seeding methods - introducing small particles of a specific medium into clouds, where the particles of seeding media are typically delivered to clouds by aircrafts or rockets, or with the aid of natural updrafts such as orographic lifting. For these reasons, traditional seeding techniques lead to high associated costs. Furthermore, seeding large volumes of cloudy air may need to be repeated due to the limited lifetime of charged particles.

Barva Innovation Center
has rich Hi-Tech R&D and manufacturing traditions since 1958. Among other developments and products we sell worldwide, we have developed and successfully tested RainStim© combined rain stimulation system in our premises in Talin city, Armenia. Application of such a system is diverse from facilitating irrigation problems, combatting the drought, preventing desertification to firefighting of forest fire and many others. These technologies car seriously contribute to the development of agriculture by increasing both yield and expanding cultivated land.




NEGATIVE ION EMISSION

Our developed combined rain stimulation method RainStim© is using powerful electron emitter in conjunction with shock wave generator. The emitter is emitting negatively charged ions and its impact is limited only to the troposphere layer of the atmosphere. By applying high voltage (70-80kVDC) to the injector, gas (air at atmospheric pressure) decay takes place and stationary corona discharge is established on the electrodes of the injector. As a result, trillions of negatively charged electrons immediately adhere oxygen molecules in the air. In wet air, these electrons become hydrated, i.e. adhere several water molecules at the expense of drying air from near-to-Earth surfaces. This creates upward moisture flux, which cause modification of the vertical humidity profile by increasing relative humidity at higher altitudes.

Negative ions collide with dust particles and aerosols in the air during such upward move until recombination with positive ions. An upward moisture flux achieved by deploying this method leads to the formation of new clouds and/or to super saturation in existing clouds, thus enhancing the development of precipitation and/or facilitating the inflow of the evaporated moisture from the near-to-Earth surfaces.

In order to enhance upward stream of such negatively charged ions, powerful ventilators are used to generate additional flux of air in the direction of ion wind. As a result, charged ions can reach higher altitudes at the height of clouds and become catalytic centers for condensation processes within the clouds resulting absorption of more liquid droplets and becoming heavy enough to fall as precipitation. Generated shock waves facilitate upward drift of ion flux as well stimulate condensation processes within the clouds.

SHOCK WAVE GENERATION


Positive impact of acoustic waves on several atmospheric phenomena like fog dissipation, stimulation of rain, hail suppression, improvement of air quality, changing temperature of atmosphere, cleaning air basin from Freon pollution heavily and negatively impacting the Earth’s ozone layer, etc. is becoming very widely regarded recent years due to increasing importance and attention to environmental issues.

Among the above mentioned acoustic waves applications, hails suppression and rain stimulation are of immense importance to agriculture especially in countries where hailstorms seriously damage crops and where precipitations are rare.

For rain stimulation purposes, we developed a special vertex cannon- an acoustic gun, which is mounted on a gas chamber operating by a gas mixture.
 The shock wave generator ignites
explosive gas mixture to the designated
chamber compartment of the apparatus and
makes repetitive blasts at time intervals of 5-
10 seconds to create sudden upward
movement of energy directed to form shock waves at cloud level to modify the internal structure of cloud banks.


Rain stimulation method using shock waves is based on propagation of acoustic waves in the air when mechanical reciprocation motion of
air molecules take place and processes of
compression and rarefaction alternate each
other. The alternating pressure in the air
leads to oscillatory longitudinal displacement
of particles, increasing frequency of particle
collisions in the compacted layer. Vapor
particles 
further grow at the expense of
coagulation, coalescence, and collision with surrounding liquid droplets, absorbing more
vapors compared to the case of
condensation. The growing particles
eventually become heavy enough to fall as
precipitation.

Shock waves generated from near-to-Earth surfaces and focused vertically up, propagate upward and generate acoustic waves at any altitude where clouds exist. As a result, acoustic waves impact on the clouds and 
lead to the acoustic coagulation of water vapor and cause precipitation of rain.

One of the advantages of acoustic impact on the clouds is its cumulative effect, i.e. the desired efficiency can be ensured by its repetitive impact. In this context, for more effective impact, the requirement for increasing the intensity of acoustic radiation over the threshold value is of prime importance.

The threshold value for intensity of acoustic radiation depends on the clouds characteristics and for so called “near-the-rain-condition” clouds it is estimated to be in the order of 100 Pa at the carrier frequency in the order of 100 Hz. In order to reach such a threshold minimum and ensure sufficient level of acoustic radiation energy density, we use several (min 10) shock wave generators.