Low visibility
For UAVs, the problem of radar visibility is relevant. Its reduction is aimed at effectively overcoming air defense zones and reducing the influence of radar interference. One of the most effective ways to solve this problem is to reduce the effective dispersion area (RCS) of the airframe. According to foreign data, the real reduction in the ESR of a UAV is by two or even three orders of magnitude. At the same time, the probability of detecting and destroying a UAV by air defense systems is reduced to several percent.
One of the main factors influencing the EPR is the configuration of the UAV, especially its elements such as air intakes and antenna compartments. To reduce the ESR of a UAV, it is advisable to use the following architectural forms of its elements:
— eliminate corner reflectors as much as possible;
— deflect flat vertical surfaces so that the normal approaching them leaves the probable irradiation sector;
— reduce the radii of curvature of cylindrical surfaces;
— apply smooth transitions;
— reduce the number of external protruding elements of the UAV;
Anti-radar camouflage of antennas is the most difficult task. At the same time, the ESR of the antennas of onboard radio systems at certain irradiation radii is the main component of the entire ESR of the UAV. In practice, the following methods of masking antennas are used:
— installation of external screens that are removed before turning on the locator or in which a radio-transparent window is formed;
— giving the antenna an oil-reflecting geometric shape with the application of a radio-absorbing coating on the structural elements of the suspension system and the equipment compartment.
External functions of the UAV
Aerodynamic and gas-dynamic systems for creating forces and moments of the UAV. The functions of the airframe to ensure the aerodynamics of the UAV are associated primarily with flight control and maneuverability of the UAV. The implementation of these methods is achieved in several ways. In most cases, an aerodynamic method is used to create forces and moments. In the classic version, the wing occupies a special position because, creating lift, it serves as the main support of the entire UAV in flight, and all parts of the UAV are installed directly on this support and with the help of intermediate elements. However, as flight speeds increase, the required wing sizes decrease, and it becomes possible to use wingless designs to reduce drag forces.
The same problem is solved by various types of fairings and fairings that cover protruding parts of the structure, as well as areas of turbulence and flow stall.
Environmental friendliness
The problem of air pollution is one of the most serious global problems facing our humanity. One of the dangers of air pollution is fuel combustion and explosions. Air pollution from human activities has caused carbon dioxide concentrations to increase by almost 30% over the past 200 years. However, humanity continues to actively burn fossil fuels and destroy forests. The process is so large-scale that it leads to global environmental problems.
