Mobility of aggregates of promising missile systems based on road trains with an active trailed link

The aggregates of advanced missile systems (AAMS) include autonomous launchers of a mobile ground missile complex, transport-and-installation, refueling, maintenance and auxiliary technical means of technological equipment, which must have operational, tactical and strategic mobility. Operationaland tactical mobility is understood as the ability of the AAMS to move from one point to another in a certain time. Strategic mobility is characterized by the adaptability of the AAMS to its loading and transporting by other types of transport, including rail, air, water. The average speed of movement is taken as a measure of mobility, which should be developed by AAMS in order to ensure the timeliness, efficiency and safety of performing the assigned tasks, as well as the possibility of getting out of the influence of the damaging factors of a nuclear explosion, primarily from excess pressure in the front of the shock blast wave. It is possible to increase the mobility of the AAMS by locating it on the basis of road trains, however, the existing designs of aggregates of road trains have disadvantages that reduce the flotation and, as a result, the average speed of movement, these include low support and geometric flotation. The geometric flotation is influenced by design factors. For example, an increase in overall width is typical for a road train, as the trailing link under the influence of lateral reactions of the supporting surface relative to the tractor track is shifted towards the instantaneous turning center. This displacement causes an increase in resistance to movement on deformable soils, and, consequently, a deterioration in flotation and a decrease in a number of other operational properties of the road train. It is possible to increase the mobility of the AAMS by placing them on the basis of a road train with an active trailed link, controlling the distribution of power flows supplied to the wheels of an all-wheel drive road train depending on the possibility of realizing free traction by each wheel, changing the position of the road train center of inflexions depending on the steering wheel angle and maneuver.</jats:p

Modernization of the cooling system for diesel engines of the YAMZ family with the aim of reducing cavitation damages

The article deals with issues related to the modernization of diesel engines to reduce their cavitation damages. During the operation of diesel engines, local fractures can occur, as a rule, the causes of these disruptions can be the vibrations of the walls of cooling cavities of diesel engines, resulting in ruptures of the liquid, which leads to higher pressures, temperatures and potential differences in the cooling sphere. These factors have a destructive effect on the surface of parts, washed with coolant. To maintain a normal thermal regime, it is necessary to remove excess heat from heated parts, that is why the cooling system is designed. One of the promising trends in the development of this system is the increase in the average temperature of the cooling liquid in the water path of internal combustion engines above 100 ° C with a corresponding increase in pressure in the jacket space, which eliminates the boiling of water. As the temperature of the coolant rises, the fraction of heat carried away with the cooler decreases, and the period of self-ignition delay decreases, and the degree of increase in pressure during combustion decreases, which has a positive effect on the operation period of engine parts. Analyzing the reliability of the liquid circuit, it must be taken into account that the efficiency of the pump depends largely on the temperature of the coolant. At a coolant temperature close to the boiling point of the coolant, cavitation phenomena occur, which are manifested in a sharp drop in the productivity of the pump due to the appearance of air and steam bubbles in the liquid. It becomes difficult to ensure the non-cavitation operation of the water pump. Cavitation in the flowing part of the pump often leads to a violation of the circulation of coolant in the circuit and overheating of the diesel. The inclusion of a high-temperature cooling system in the water system of the mixing and supporting device parallel to the water pump is one of the simplest and most effective ways to increase the pump's available cavitation supply.</jats:p