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This paper presents the results of theoretical computer-aided research of the microclimate parameters in the vehicle passenger compartment during operation of one of the widely used schemes of heating system in the passenger compartment, taking into account the breathing of passengers. Theoretical researches of the heating system operation in the passenger compartment taking into account passenger breathing have been conducted. Distribution of microclimate parameters in the passenger compartment cross-section, in the case of using a heating system having one compartment heater, with and without taking into account the breathing of passengers, has been obtained. The assessment of the effect of passengers' breathing on the microclimate parameters in the passenger compartment has been carried out. The outcomes of this research may be of interest to specialists involved in the design and ergonomics of wheeled vehicles and labor protection.

The work objective is to assess the effect of cutter band angle on the power required for transporting the snow by the cutter feeder of the rotary snowplow and its performance, taking into account the interaction of snowflakes with each other. The problem to which the paper is devoted is to find out the influence of the angle, the size of the transported particles on the productivity of the feeder cutter and the power spent on moving the snow as a group of interacting flakes of finite size. Research methods: theoretical studies and simulation of the feeder cutter operation during transportation of snow as a group of interacting flakes of finite size. The novelty of the work lies in the fact that simulation, for the first time, gives theoretical description of changes in the productivity of a cutter and rotary snowplow feeder of and the power costs for transporting snow depending on the cutter band angle and the typical size of snowflakes in conditions of their interaction with each other, and also approximating equations of changes in productivity and power costs depending on the cutter band angle and typical size of snowflakes. The study results show that an increase in the cutter band angle leads to a nonlinear increase in power costs for transporting snowflakes, described by a fourth degree polynomial. An increase in the typical flake size of the transported snow in the cutter feeder of the rotary snowplow also causes a nonlinear increase in the power costs for transporting snow, which is described by a second degree polynomial. The increase in productivity with an increase in the cutter band angle is described by a fourth degree polynomial, and with an increase in the typical flake size by the third degree one. The areas of maximum power consumption and maximum productivity have an offset relative to each other in the coordinates of the typical flake size and the cutter band angle. Conclusions: the influence of the cutter band angle and the size of transported snowflakes on the main parameters of the cutter feeder operation are defined. The results of theoretical studies correlate with the results of practical studies, which indicates the feasibility of using a mathematical model that takes into account the interaction of transported snowflakes in further studies aimed at improving the efficiency of feeder of the rotary snowplows.

Introduction. A distinctive feature of working conditions in the Arctic territories is the long period of exposure to low temperatures. Passenger transportation by road is becoming one of the key aspects of ensuring the continuity of the production process. The task of delivering workers to the place of work, moving them between work zones during a work shift is solved by using wheeled vehicles of various categories. One of the most widespread types of wheeled vehicles used to transport workers is the M3 category wheeled vehicles with a capacity of no more than 22 passengers. Ensuring the thermal comfort of vehicle passengers seems to be relevant, since ensuring biophysical compatibility minimizes the risks of cold injury by workers and maintains a high level of performance.Materials and methods. The results of the analysis of the Russian and foreign studies in the direction of ensuring thermal comfort and ensuring biophysical compatibility in confined spaces are presented. The results of computer modelling of the dynamics of microclimate parameters in the passenger cabin of a wheeled vehicle of M3 category with a capacity of no more than 22 passengers are presented.Results. The paper presents the results of theoretical studies, microclimate parameters in the passenger compartment of vehicles, taking into account the breathing of passengers and changes in the gas composition of exhaled air. Theoretical studies of the operation of the heating system of the passenger compartment were carried out, taking into account the refined breathing model of passengers. Distributions of microclimate parameters in the section of the passengercompartment were obtained when using a heating system with one heater; the impact of passengers’ breathing on the parameters of the microclimate in the passenger compartment was assessed.Discussion and conclusion. Based on the numerical solution of the system of heat transfer equations, directions for further research and recommendations are formulated to ensure thermal comfort in the passenger compartment of a wheeled vehicle at low temperatures. The materials of the work may be of interest to specialists involved in the design and ergonomics of wheeled vehicles, labor protection.

Introduction. An increase in the efficiency of snow removal work is due to an improvement in the characteristics of all components of this process, however, the creation of fundamentally new design schemes for snow blowers allows us to make qualitative changes in the problem of winter maintenance of roads, residential areas, etc. Materials and methods. A description of analytical studies of the dependence describing the design parameters of the feeder cutter for a rotary-milling snow blower is presented, on the basis of which the concept of a fundamentally new design of the feeder for a rotary-milling snow blower is formed. The description of the mathematical model of the presented design of the feeder is given.The structural scheme of the vertical cutter of the feeder of the rotary-milling snow blower is presented. Described are the main assumptions made in the compilation of the design scheme for the operation of the vertical cutter of the feeder of the rotary-milling snow blower. Equations have been obtained that describe the movement of a group of snow particles transported by a vertical mill and interact with each other in the process of movement, analytical dependences of the forces of normal reactions of the working elements of a vertical miller on its design and technological parameters. The initial conditions for the numerical solution of the presented equations of operation of the vertical milling cutter of the feeder of a rotary-milling snow blower are described.Results. The structural scheme of the vertical cutter of the feeder of the rotary-milling snow blower is described. Described are the main assumptions made in the compilation of the design scheme for the operation of the vertical cutter of the feeder of the rotary-milling snow blower. Equations are obtained that describe the movement of a group of snow particles transported by a vertical mill and interact with each other in the process of movement, analytical dependences of the forces of normal reactions of the working elements of a vertical mill on its design and technological parameters. The initial conditions necessary for the numerical solution of the presented equations of operation of the vertical milling cutter of the feeder of the milling-rotary snow blower are determined.Discussion and conclusion. The description of the mathematical model of the original design of the feeder of the throw-away snow blower is given. The necessity of a more complete substantiation of the initial conditions for the numerical solution of the equations of the work of the feeder of the throwing snow blower is indicated. This mathematical model makes it possible to proceed to a detailed study of the described cutter design in order to determine the working ranges of the design and technological parameters of the feeder with a vertical cutter.