A significant problem of a dual fuel engine is the increase in emissions of unburned methane (CH₄) at low loads due to deterioration of combustion caused by a high excess air coefficient (α). Experimental parameters of a dual fuel engine are presented, which showed a significant increase in CH₄ emissions with a decrease in load. To reduce the value of α, the use of a throttle valve was examined. The working process of a dual fuel engine was simulated in the AVL FIRE and BOOST environment. The change in combustion process parameters and fuel efficiency with the decrease in α as the throttle valve was closed at a load of 25% were analyzed. Two versions of the dual fuel engine were considered: the standard one and the new one with smaller injector and combustion chamber of the gas engine. When α was reduced from 4.9 to 2.2 by closing the throttle valve, the indicated efficiency increased by 12…16.0 % and CH₄ emissions decreased 10.2…11.7 times. The brake specific fuel consumption increased by 17.4% due to increased gas exchange losses.

The effective performance of internal combustion engines largely depends on the correct choice of the boost system and, above all, the turbocharger (TC). When developing a turbocharged engine, one should go through a large number of TC in order to find the option that provides the best engine performance, especially in case of a two-stage boost system. Based on the analysis of the experimental characteristics of three compressors with a wheel diameter in the range of 50...95 mm, generalized characteristics have been obtained that make it possible to select quickly the best TC for any automobile engine and calculate its performance. The main parameters of the compressor are recalculated into dimensionless parameters, which are similar for compressors of different size. Next, the dependences of dimensionless indicators on the main control factors are described by polynomials. The difference between the experimental parameters of the compressors and those calculated by the generalized characteristics in the field of maximum efficiency does not exceed two percent.

A method for determining the performance of hybrid power plant units of a vehicle during road tests is proposed. The description, design, workflow, hardware and software of the developed device for determining the torque on the drive wheel of a vehicle are given. An improved method for determining the current fuel consumption of an internal combustion engine by a volumetric method is proposed. The results of the work will allow determining the speed characteristics of an internal combustion engine by effective power, effective torque, effective specific and hourly fuel consumption during engine operation, both in steady-state and non-steady-state operating modes, as well as mechanical characteristics and efficiency characteristics, both in engine mode and in generator mode, of electric machines for hybrid power plants.

A method for reducing the fuel consumption per mile for parallel and series-parallel hybrid power units with a given electric energy consumption in the driving cycle by optimizing the operating and design parameters is proposed for automobile hybrid power units. The developed algorithm contains three successive stages: combining similar driving modes into groups, eliminating inefficient operating combinations of units, and subsequent multi-parameter evolutionary search. This allows for a significant reduction in the required computational costs. Using the example of the Toyota Prius ZW52, it is shown that a rational choice of gear ratios for the hybrid power unit and its regulation in accordance with the developed algorithm with a given electric energy balance ensures a reduction in fuel consumption per mile in the WLTC driving cycle by up to 7.38% without a significant deterioration in traction and speed properties.

The work was carried out in order to confirm the equivalence of the value of the moment of mechanical losses obtained in free acceleration modes to the results of bench tests. The study was carried out as part of the development of a technique for indirect indexing – calculating gas forces and their operation based on an analysis of the dynamics of crankshaft rotation. Indirect indexing is important for monitoring the operation of the internal combustion engine in a car during its operation and can be implemented as an additional algorithm of the electronic control unit or an external electronic module operating based on the signal of the crankshaft position sensor and information received from the CAN bus. The proposed empirical method for determining the moment of mechanical losses is based on calculating the work of the resistance forces over a certain angular interval, as the difference between the work of the gas forces and the change in kinetic energy of the moving parts of the engine during its operation at various idle modes – free acceleration and run-off at different positions of the engine control. The angular velocity and position of the crankshaft are determined based on the signal processing of the standard crankshaft position sensor, and the operation of the gas forces is based on the results of direct indexing. The verification of the readings of pressure sensors in the cylinder is described. It was performed by turning off the cylinders of the engine running on the engine stand. The article also discusses a technique for determining the moment of inertia of rotating engine parts at unstable idle. The determination of the moment of inertia is necessary to calculate the kinetic energy of the moving parts of the engine. The analysis of experimental data confirming the equivalence of the moment of mechanical losses in stationary and transient modes is performed.

This article contains a description and results of motor tests conducted as part of the experiment. An analysis of experimental data has been carried out, confirming the equivalence of the moment of mechanical losses in stationary and transient modes.

Today, WIM systems are widely used all over the world. They are installed on public roads and are designed to monitor the weight and dimensions of passing vehicles. These systems have been developed and modified over time, but they still have many drawbacks and issues. The main problems with these systems are related to their high sensitivity to the drivers' control over the vehicle being weighed. When the driving parameters of the vehicle being analyzed change, these systems become unable to perform their intended function. In this work, a fundamentally new architecture of the WIM system was proposed, which is based on the method of platform weighing of vehicles in motion. The developed system is completely free of the shortcomings and problems of the WIM systems currently used.

This article presents an analysis of methods for calculating the protective properties of a torque converter. Specifically, it analyzes existing methods for accounting for the torque converter's influence on a dynamic system and selects optimal dynamic properties for a hydraulic transmission. A detailed dynamic calculation of the driving portion of the system with a hydraulic transmission is presented, taking into account the latter's damping properties and the influence of the driven portion of the transmission. The paper presents the results of calculating a hydromechanical transmission with a torque converter with an active diameter of 340 and presents the characteristics of the reduced coefficient (and relative moment of inertia) depending on the torque converter operating mode, the pump wheel speed, and the forced vibration frequency. The calculation demonstrated the need to include a torsional vibration damper in the hydraulic transmission system and allowed for the determination of its optimal parameters.

Introduction (problem statement and relevance). In domestic and foreign literature there are no calculation methods for the suspension of a self-propelled modular transporters (SPMT) with a double lever system, which can lead to unequal strength and non-optimality of the developed design of the SPMT suspension. The article presents a method for determining the forces that arise in the nodes of the SPMT suspension when lifting and lowering a load.

The purpose of the studies was to establish the dependence of forces at the points of a hydraulic suspension with a double lever system on the stroke of the hydraulic cylinder rod using kinematic and force analysis of the suspension design.

Methodology and research methods. The studies were conducted using methods of mathematical modeling and methods of theoretical mechanics.

Scientific novelty and results. The developed methodology and obtained dependencies of the change in forces at the studied points on the stroke of the hydraulic cylinder rod of the SPMT suspension determine the scientific novelty of the studies.

Practical significance of the studies is that the information presented in the article can be used in the design of suspension elements of a self-propelled modular transporter and in the creation of a self-propelled modular transporter

Modern special-purpose road trains must meet special requirements for cross-country ability, maneuverability, stability, and controllability. In this regard, the trailer link is equipped not only with a traction drive for activation, but also with a wheel steering control system, as well as a mechanism for controlling the folding of links in the fifth-wheel coupling device. When calculating the parameters of curvilinear motion of such road trains, the mathematical model becomes significantly more complicated. The greatest difficulties arise when describing the transverse reactions in the contact patch of elastic wheels with the supporting surface and the elastic-damping forces in the fifth-wheel coupling device. The alternative method for calculating the parameters of curvilinear motion of an active road train with steered wheels proposed by the authors, which consists in considering the dynamic equilibrium of the tractor and semitrailer separately, was used to study the stability of road trains with various design solutions when performing standard maneuvers.

The article investigates the problems of passenger transportation quality by automobile transport in urban environment conditions. The rationale for the study is associated with the need to improve population mobility and reduce the transport load on cities. The aim of the work is to analyze key indicators of transportation quality and develop recommendations for improving transport services. The research methods include analyzing existing problems, assessing passenger satisfaction, and using statistical and expert analytical methods. The results show that the main problems are infrastructure wear, inefficient transport management, and the lack of modern accounting and control systems. The conclusions emphasize the importance of modernizing the transport system, updating the rolling stock, and adapting the regulatory framework.

Modern engineering education requires continuous monitoring of knowledge acquisition quality. The analysis of students’ academic performance is an important tool for identifying knowledge gaps and taking corrective measures. This paper presents an analysis of entrance testing and interim assessment results of students, along with a review of recent changes in the physics curriculum at the MADI technical university. Special attention is given to the propaedeutic course as a tool for academic adaptation. The study concludes that there has been a reduction in academic workload and an increase in the complexity of the initial stage of physics education.

The paper provides data on students' academic performance in the 2024/25 academic year in the subject of "Physics". It also analyzes changes in the number of hours allocated to studying physics in the Work Programs of the discipline.

The article considers non-specialized physical education (NPE) as an obligatory component of the general education system and draws attention to the need to strengthen the educational aspect of the process of physical education for young people, making it more intellectualized in order to increase the overall level of education of young people in the field of physical culture and sports. To identify the most important aspects of NPE in a technical university, the article analyzes the definitions of this pedagogical process by various specialists based on a review of the literature. Taking into account the accumulated practical experience, the implementation of the identified main provisions of the NPE at the Department of Physical Education at MADI is being considered. Special attention is paid to students' research activities, annual monitoring of their physical condition, and the interdisciplinary integration of technical and humanities knowledge through the implementation of interdisciplinary connections.