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Trudy NAMI

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No 3 (2024)
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ENGINE DEVELOPMENT

6-10 107
Abstract

Introduction (problem statement and relevance). The presented materials reasonably prove the need to define the maximum allowable value (volume) of crankcase gas (CG) emissions by motor vehicle internal combustion engines (ICE’s), which determines objectively their ultimate life and functionality condition.

The purpose of the study is to investigate and identify the main cause of the ICE oil aging process with increasing CG emissions.

Scientific novelty and results. The studies have identified the minimum volumes of CG emissions during normal operation and ultimate emissions unacceptable for further operation of an ICE.

The practical significance consists in changing the CG separator operation not to forward the condensed oil vapor with particulate matters to the oil in the crankcase, but to dispose thereof, which will allow increasing the oil change intervals when in maintenance.

11-19 120
Abstract

Introduction (problem statement and relevance). The paper analyzes the impact of changing the position of one of the ring-type Helmholtz resonators in relation to the second one on the adjustment of the required sound attenuation frequency. Along with that, it covers the impact of temperatures and geometrical parameters of the resonators. The relevance of the paper consists in the possibility to predict and update the adjustments originally provided in the design.

The purpose of the study is to determine the dependences of the ring-type resonator parameters required for resonant frequency adjustment.

Methodology and research methods. The studies were carried out by means of numerical calculations using the finite element method with further introduction of the results in the form of dependence diagrams.

Scientific novelty and results. An example of practical application of adjustment of two co-operating resonators is given. At the moment, there is a great number of papers devoted to the classical Helmholtz resonator and its resonant frequency adjustment. But there is no detailed information about the ring-type resonators.

Practical significance. The studies conducted are of great practical importance when developing and researching new configurations of Helmholtz resonators within real exhaust systems.

20-32 146
Abstract

This is the third part of the research work under the common title “On fuel and deposits”. The paper contains a brief review of methods and standards to determine the tendency of automotive gasolines to “cold” and “hot” deposit formation. Some peculiarities and disadvantages of using of foreign methods and foreign “reference” engines to assess the quality of Russian gasoline for the Russian market have been noted. The authors believe that there are all prerequisites in place in order to create a state-of-the-art scientific & methodological and laboratory & research base in Russia for development of proper inhouse criteria and methods to assess the quality of motor fuels with a research infrastructure independent of external circumstances.

33-46 73
Abstract

Introduction (problem statement and relevance). At present, the majority of automobile manufacturers have organized mass production of plug-in hybrid vehicles, i.e. PHEV’s. This solution allows driving using electric traction only for a long time due to an increased capacity battery which can be charged from both an external source and the internal combustion engine (ICE) as well as recuperate the brake energy. In the near future, the demand for such power plants will show significant increase, especially in urban environment. During electric driving, the ICE may not be started for a long time, hence the canister will not be purged. In this regard, studying of evaporation generation processes and finding solutions for their minimization are relevant.

The purpose of the study is to develop approaches for the fuel tank isolation valve (FTIV) control algorithm depending on the fuel volume in the vehicle fuel tank.

Methodology and research methods. The fuel vapor generation in the fuel tank vapor space has been analyzed for an open evaporation system, in which the vapor volume is constantly connected to the canister, and for a closed system, where the vapor volume and canister are separated by the fuel tank isolation valve. The influence of change in temperature, composition and amount of the air-fuel mixture in the vapor space on the fuel tank pressure has been determined.

Scientific novelty and results. The equations for determination of the vapor mass in the vapor space with the closed fuel tank evaporation system (Mv), for the vapor mass during the canister feed (ΔMcv), total heating of the mixture up to a certain temperature depending on the number of canister feed steps (Δt), for the air mass in the vapor space of the closed fuel tank evaporation system depending on the number of canister feed steps (Man) have been obtained.

Practical significance. The equations have been obtained allowing determination of the individual and total canister feed during fuel heating within the given temperature interval. The dependencies obtained allow forming optimal algorithms to control the canister feed by varying the pressure release depth depending on the fuel properties and vapor space volume with successive steps of the canister feed and temperature intervals between them.

47-56 132
Abstract

Introduction (problem statement and relevance). The relevance of the study is determined by specific operational features of low-temperature proton-exchange membrane hydrogen fuel cells (FC). The operating temperature of such power plants is lower than in case of an internal combustion engine, the maximum coolant temperature of the FC in question is 80°С. In order to ensure this operating temperature, the cooling system radiators shall have a large heat sink or removal area, overall dimensions and weight. Assessment of the FC cooling system efficiency allows creating designs with more rational parameters.

The purpose of the study is to determine the heat dissipation capacity of a liquid cooling radiator in various operating conditions of the FC.

Methodology and research methods. In the course of the work, a simulation model of a FC cooling system has been developed in order to determine the hydraulic resistance and coolant flow rate. After that, a finite element model of a radiator portion has been created, which served for heat dissipation capacity calculation for two operating conditions of the FC.

Scientific novelty and results. As a result of the calculation, the values of heat removal capacity of the FC cooling system at ambient temperatures of 20°С and 30°С have been obtained.

Practical significance. The results of the study will help to understand the choice of parameters of a cooling system for FC power units and plants.

AUTOMOBILE DEVELOPMENT

57-70 132
Abstract

Introduction (problem statement and relevance). Ensuring the necessary strength, stiffness and durability of load-bearing structure components of open-pit dump trucks is an important engineering task in the absence of regulations and standards of loading simulation. Therefore, the focus area of developing and accumulating of the regulatory and methodical base for building an effective design process for chassis and load-bearing systems of open-pit dump trucks is highly relevant.

The purpose of the study is to develop the procedure for simulation of open-pit dump truck loading by means of cascading the external force factors in order to determine the standardized sequence when forming a cascade of test loads acting on mechanical parts of the open-pit dump truck in the initial design stages.

Methodology and research methods. According to the goals and objectives of the study, the following methods were assigned: the mathematical simulation method; statistical data processing methods; formalization and specification of calculated load cases based on vehicle theory formulas.

Scientific novelty and results. The results are formed as a descriptive part of the main peculiarities of the open-pit dump truck loading simulation procedure as well as some intermediary approbation results proving the suitability, efficiency and reasonability of the procedure developed. The scientific novelty consists in application of the open-pit dump truck loading simulation method on the principle of “loading –unloading – statics” considering the simultaneous influence of inertia loads and loads in the tyre-to-road contact patch while maintaining the quasistable state of the dynamic model, which relatively reduces the simulation time by more than 20%.

Practical significance. The procedure developed is recommended to be applied in the early design stages in order to simulate typical and non-typical open-pit dump truck operational conditions or modes so that to define the loads acting on the open-pit dump truck load-bearing system and chassis suspension guiding devices for further operational reliability calculations.

71-79 94
Abstract

Introduction (problem statement and relevance). Modern daily life is increasingly dependent on motorcycles and power products, especially in large cities where motorcycles are popular due to their maneuverability. Today’s widespread of vehicle automatic piloting and self-driving systems creates new dangers increasing the number of road traffic accidents involving motorcycles. Despite the growing popularity of motorcycles, there is a lack of research on their passive safety, and that leaves gaps in understanding how to increase the protection level for motorcyclists.

The purpose of the study is to justify the development of a test procedure and assessment criteria for motorcycle passive safety.

Methodology and research methods. In order to achieve the purpose in view, the development of a domestic test procedure using deformable standardised barriers simulating vehicles is proposed. The analysis of road traffic accident statistics in different countries will allow us to identify the main patterns and regularities, based on which the test program and conditions will be developed. The virtual tests to be conducted using the LS-DYNA software and validation of calculation models will help to justify the optimal test conditions.

Scientific novelty and results. The research results will provide a new approach to motorcycle passive safety assessing by identifying the key parameters and conditions affecting motorcyclist injuries. The scientific novelty consists in development of more accurate and realistic test methods that can improve the effectiveness of motorcycle safety assessment.

Practical significance. Development and implementation of the motorcycle passive safety test procedure are important to ensure safety of motorcyclists. The results obtained can provide grounds for creation of regulations and crash test series, as well as contribute to development of safe motorcycle designs.

REVIEWS, ANALYTICS

80-91 83
Abstract

This is a continuation of the article of the same title published in previous issue. The major focus is on providing electric vehicles with critical units, i.e. batteries and fuel cells, as well as materials needed to manufacture them. It is shown that the current state of the Russian industry and technologies cannot guarantee their production in the scopes required for complete replacement of motor vehicle internal combustion engine power plants with electric powertrains yet.

92-100 96
Abstract

Introduction (problem statement and relevance). The comprehensive question of environmental “health” and handling the problems connected with excessive emissions of hazardous substances into the environment can be solved through active introduction of vehicles having the minimum impact on natural processes. This scientific paper is an analytical survey of the existing power plants of electrified vehicles (EVs) taking into account the up-to-date statistical indicators to increase their mileage.

The purpose of the study is to analyze the experience of creation, development and improvement of EV characteristics.

Methodology and research methods. The methods used in the scientific paper are based on the fundamentals of electrical engineering, electronics, automated electric drive basics, methods of research tests, and vehicle design foundations.

Scientific novelty and results. Within the study, analysis of EV power plant combinations, as well as systems and ways of mileage increasing has been performed. The analytical estimation of options to improve the EV energy efficiency has been offered.

The practical significance consists in the results of the analytical estimation of the options to improve the EV energy efficiency. The results obtained during the study and accompanying recommendations are aimed at mileage increasing and reduction of toxic emissions into the atmosphere, as well as at creation of an additional positive trend towards mass use of EVs among the population.

101-114 100
Abstract

Introduction (problem statement and relevance). The article reviews directions of improvement of transport power plants and internal combustion engines (ICE) when using hydrogen gas generators.

The purpose of the study is to analyze various methods of storage of hydrogen to use it in motor vehicle or transport power plants implemented in machinery and in motor vehicles, as well as to analyze directions of development of hydrogen gas generators usage.

Methodology and research methods. Analysis of information about production and use of hydrogen as a promising fuel for motor vehicles. Assessment of efficiency of methods of hydrogen generation from ammonia, by the method of steam reforming and by means of methane thermal pyrolysis.

Results. The accomplished analysis of the methods of hydrogen storage and application in various fields of machinery has shown that use of hydrogen as part of synthesis gas opens up additional opportunities in improvement of power plant characteristics and energy efficiency of its application. The prospectivity of ammonia as a hydrogen energy carrier for thermal generators is shown. The calculations conducted have shown that thermal expenditure of energy for hydrogen generation from its combustion in the ICE amounts to 10.7%.

Practical significance. Generation of hydrogen from ammonia with its subsequent supply to the ICE combustion chamber ensures high efficiency of the diesel operation process. Meanwhile, the availability of ammonia in-vehicle simplifies the organization of the catalytic process of selective reduction of NOx in the diesel engine to the ecologically safe level.



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ISSN 0135-3152 (Print)