Vol 15, No 4 (2021)

Original Study Articles

Substantiation of methods for determination of the effectiveness of the use of alternative fuels in automotive diesel engines

Buzikov S.V., Plotnikov S.A.


The subject of the research is to determine the parameters of the operating cycle of a tractor diesel engine when it is running on a mixed fuel, consisting of diesel fuel and rapeseed oil. The main goal of this work is to determine the efficiency of using alternative fuels in automotive diesel engines. In order to determine the dependences of the parameters of the operating cycle, the theoretical and experimental studies of a tractor diesel engine were carried out on the following compositions of mixed fuel: with a rapeseed oil content of 20%, 55% and 80%, as well as pure diesel fuel. As a result of the research, the following was obtained: a nomogram for determining the value of the decrease in the ratio of the indicator efficiency to the excess air ratio, the dependence of the ratio of the indicator efficiency to the excess air ratio on the excess air ratio for different compositions of mixed fuel, diesel engine crankshaft rotational speed, load at 1800 min-1 and 1400 min-1. It was experimentally established that an increase in the proportion of rapeseed oil in mixed fuel from 0 to 80%, the speed from 1400 to 2000 min-1 and the excess air ratio from 1.18 ... 1.22 to 4.32 ... 5.61 led to a decrease in the indicator efficiency from 0.46 to 0.35, and the ratio decreased from 0.30 to 0.08, an increase in the load from 0.2 to 1.2 MPa, at 1800 min-1, and 1400 min-1, and the excess air ratio from 1.17 ... 1.68 to 3.53 ... 3.60 led to a decrease in the indicator efficiency from 0.44 ... 0.40 to 0.28 ... 0.22, and the ratio from 0.34 ... 0.25 to 0 , 10… 0.09, respectively. A 4.5% reduction in the ratio is theoretically calculated when the diesel engine runs on a mixed fuel containing 80% rapeseed oil as compared to pure diesel fuel, and this reduction by 4.1% has been experimentally confirmed. The convergence of the calculated value of the decrease in the ratio with the experimental data was 91.11%. In this regard, the well-known statement about the equality of the input of heat with fuel requires clarification.

Izvestiya MGTU MAMI. 2021;15(4):2-8
pages 2-8 views

Study of existing designs of the peristaltic principle pumps

Grishin A.I., Lepeshkin A.V.


Peristaltic pumps are used in a wide variety of applications due to their tightness, ease of maintenance and accurate delivery. Nevertheless, the use of peristaltic pumps is limited by their disadvantages: short service life of the working body and uneven feed. This work provides an overview of the existing design solutions for pumps. The main advantages and disadvantages of the most common modern designs of peristaltic pumps are considered. The developed design solutions are presented. These solutions are designed to extend the service life of the elastic working body of the pump. These include a spiral hose design, where hose life is improved by reducing the number of cyclic compressions using just one roller. Another solution is to operate the pump with incomplete compression of the working element, which reduces the stress values and thereby prolongs the service life of the working element. The special shapes of protrusions in the compression area were developed in order to compensate the decrease in flow caused by the operation of the pump with incomplete compression of the working member. The paper provides an overview of solutions to reduce the uneven flow of a peristaltic pump. The simplest of these is the use of multiple parallel channels. In other designs, the elimination of flow pulsations is achieved with a pneumatic damper. There is also a constructive solution, in which a special algorithm of actuation of five squeeze elements is used for uniform supply, each of which compresses only its own section of the pump working body. Based on the analysis, it is shown that in order to eliminate the disadvantages of peristaltic pumps the various methods are used. Nevertheless, those methods need further improvement.

Izvestiya MGTU MAMI. 2021;15(4):9-17
pages 9-17 views

Automation of the design of the impeller of a radial-axial hydraulic turbine

Zharkovskiy A.A., Shchur V.A., Omran M., Staseyev A.A.


The article describes approaches to the design of a vane system of radial-axial hydraulic turbines based on an automated design system developed at SPbPU using the Python programming language. The specified system currently includes the following modules: selection of the main parameters of the hydraulic turbine, construction of the meridional projection of the impeller, calculation of the potential flow and construction of the blade system of the radial-axial hydraulic turbine. The choice of the main parameters of the hydraulic turbine is based on the technique generally accepted in hydraulic turbine engineering, which has been digitized and introduced into the software package. The paper considers and analyzes different approaches to the design of the meridional bypasses of the flow path in the area of the impeller of a radial-axial hydraulic turbine, a comparison of the results of their construction using different methods is given. A technique that is most suitable for algorithmization in the software package based on the results of the analysis was selected. The construction of streamlines and the calculation of velocities along them are presented on the basis of the calculation of the potential flow in the meridian section. The design of the blade system of the hydraulic turbine was carried out by the method of solving the direct axisymmetric problem of the theory of hydraulic machines. As an example, a blade system of a radial-axial hydraulic turbine was designed for a head up to 75 meters, the initial parameters of which correspond to hydraulic turbines-analogues of similar speed. The designed hydro turbine was calculated in Ansys, and the results confirmed its excellent energy properties. It is planned to further develop the software package in terms of automatic construction of 3-dimensional solid models of the flow path, which can later be calculated by the methods of computational fluid dynamics and optimized to obtain hydraulic turbines with parameters corresponding to the current state of the art.

Izvestiya MGTU MAMI. 2021;15(4):18-26
pages 18-26 views

Starter-generator sets of modern vehicles

Kagdin V.N., Maleyev R.A., Zimin A.N., Zuyev S.M., Yakhutl' D.R.


This article describes the purpose and applications of the starter generator set. The modes of operation of a starter-generator set are considered both as a sequential excitation direct current electric motor, which rotates the shaft of an internal combustion engine, and as a generator, when an electric machine operates as a direct current source of independent excitation, supplying power to electric control circuits, electric motors of auxiliary electrical equipment, lighting and battery charging. Additional functions of a starter-generator set in the form of a start-stop system, regenerative braking, booster acceleration of a vehicle, damping of torsional moments of the shaft of an internal combustion engine and control of energy flows in the on-board network were studied.

The choice and substantiation of the optimal scheme, as well as the design of the starter-generator device, were carried out. The main technical and economic parameters of the starter-generator set were determined. The design of a starter-generator set was presented. This design is a reversible electric machine. A block diagram of a starter-generator set was developed.

Electrical machines used for starter-generator sets are considered. The design of an asynchronous machine with a squirrel-cage rotor, a synchronous machine with electromagnetic excitation, a valve machine with permanent magnets, a contactless machine, a synchronous machine with permanent magnets, and a valve machine with self-excitation are described. A review and analysis of electrical machines used in starter-generator sets of leading foreign companies is carried out.

The design of a reversible induction-dynamic machine is considered. The rotor rotates outside, and not inside the motor and is a short-circuited winding with a cast aluminum cage. The calculation of the main parameters of a reversible induction-dynamic machine was carried out both in the starting and in the generator modes. The calculation using a method similar to that of an induction motor was carried out.

Izvestiya MGTU MAMI. 2021;15(4):27-32
pages 27-32 views

Development of a complex of mathematical models of a vehicle suspension for fatigue life analysis

Kulagin V.A.


The reduction in the duration of the development of new vehicles and the associated desire to reduce the costs of automotive plants contribute to a more active application of mathematical modeling to solve engineering problems. The tasks, which are analyzing and predicting the fatigue life of vehicle components and assemblies, can be solved using a set of methods and tools of mathematical modeling.

This article discusses the development of a complex of mathematical models of the front and rear suspensions of a passenger automobile, which have the properties necessary for accurate reproduction of wheel loads and dynamic behavior of the suspension as a mechanical system. The complex of mathematical models is implemented in a multi-link modeling environment. The models are designed to carry out a subsequent validation study of the loading of individual suspension components during forced service life tests. In the future, this complex of mathematical models can be used for simulation of semi-natural forced resource tests of the suspension module, as well as a sample for the development of suspension models of other automobiles.

The purpose of this work is to form sufficient requirements for mathematical models for the implementation of fatigue durability studies using mathematical modeling methods and obtaining reliable calculation results. Research engineers will be able to follow these requirements to determine and collect initial data for the development of their own mathematical models.

Izvestiya MGTU MAMI. 2021;15(4):33-42
pages 33-42 views

Numerical simulation of cavitation in the flow path of a reversible hydraulic machine for a head up to 250m

Seleznev V.N.


In areas where thermal and nuclear power plants are mainly located, the problem of lack of maneuverable capacities, the coverage of peak loads and the passage of periods of reduced energy consumption is solved through the construction of large pumped storage power plants (PSPP). To create highly efficient flow paths for pump-turbines, one of the modern trends is the use of numerical modeling of three-dimensional fluid flow. Nowadays, there are many software products that implement numerical modeling by the finite volume method. The most famous among them are Fluent, CFX, StarCD, Numeca, Flow Vision and CADRUN. Verification of the computational model remains an urgent task. It is important to choose a methodology that will allow you to get an acceptable result with optimal time spent on preparing data and conducting computational studies.

The article examines the flow path of a radial-axial pump-turbine designed for use at a maximum head up to 250m. Numerical modeling of the cavitation process arising in the turbine mode at a significant distance from the optimum of the characteristic was carried out. The calculations were performed using the Ansys CFX software package, version 2021R1. A brief description of the problem statement, the computational grids used and the assumptions made is given. Comparison of calculation results with experimental data is presented. A qualitative comparison of the cavitation origination regions obtained by numerical simulation with the data of monitoring the state of the base metal and welded joints of the hydroelectric unit impeller by the method of non-destructive testing is carried out.

The aim of the work was to present an “economical” technique for numerical simulation of cavitation to determine the places of possible occurrence of cavitation wear. The technique consists in describing the formulation of the problem, the computational grids used and the assumptions made for the optimal use of computing resources without a significant loss in the accuracy of the results.

Izvestiya MGTU MAMI. 2021;15(4):43-48
pages 43-48 views

Results of experimental studies of an agricultural tractor with an elastic-damping mechanism in a power train

Sen'kevich S.E.


Improving the operational efficiency of agricultural tractors is one of the main factors that helps to increase productivity while significantly reducing energy costs. The developments that are associated with improving the design of power transmissions for wheeled agricultural tractors are very important, because its indispensable condition is to increase labor productivity in agricultural production. Achievement of the required characteristics of agricultural tractors is determined by the properties of the power train and the interaction of associated systems. One of the main qualities of a power train should be the ability to absorb torsional vibrations and damp the load.

The article presents studies of the constructive improvement of the power transmission of an agricultural tractor by installing a developed elastic-damping mechanism using the example of a tractor of a small traction class. Considering the relevance of the topic, the article solved the problem of determining the influence of the elastic-damping mechanism installed in the power transmission of the tractor on its operation with the cultivator.

The paper analyzed the cross-correlation function and the mutual spectral density of two processes: the angular speed of rotation of the crankshaft of the engine and the angular speed of rotation of the drive wheel, which showed a change in the speed of propagation of passing frequencies of load oscillations along the shafting and displacement of the frequency of disturbing influences.

Izvestiya MGTU MAMI. 2021;15(4):49-59
pages 49-59 views

Analytical determination of static and dynamic elastic characteristics of pneumohydraulic suspension systems

Tsipilev A.A., Nakaznoy O.A.


When developing new suspensions for tracked and wheeled vehicles, as well as in the so-called reverse engineering of existing structures (including in the educational process of training personnel), it is necessary to solve the problem of finding the elastic characteristics of the suspension. In the first case, it is necessary to ensure the fulfillment of the specified tactical and technical requirements, in the second - to restore the form of characteristics according to a known design. Both of these tasks are greatly complicated in the absence of precise and universal analytical dependencies suitable for determining the characteristics of elastic suspension elements of various design implementations. The experience of interaction with some factories shows that designers, not being able to qualitatively calculate the elastic characteristics, use the method of selection and analogy, when for a new vehicle they use the suspension as on the old one, scaling it in size in order to approximately keep the values of working pressures. The numerous bench tests are carried out, which results are used for selecting required charging volume and pressure. Suspensions with backpressure cause particular difficulty, since not only the final characteristic, but also the performance of the entire unit depends on the combination of volumes and pressures of the two chambers, which work in antiphase: when one is loaded, the other is unloaded, and vice versa. Using analytical dependencies will reduce the time spent on design, to parameterize, to a certain extent, the suspension kinematics, to obtain the values of the equivalent suspension stiffness, and also to be able to develop the characteristics of the model range of pneumohydraulic springs for vehicles of various weight categories.

This article presents a technique for the analytical determination of the characteristics of pneumohydraulic springs of various designs. The options include both actually used in modern and historical technology (in particular, on BMD-1, 2, 3, 4; GM-352; Ural Typhoon; Object 775, etc.), and obtained by combining various structural elements, which implementation can be useful in the educational process in training personnel. The dependences presented in the article make it possible to obtain static and dynamic elastic characteristics at various polytropic indices and are suitable for the design of suspensions for wheeled and tracked vehicles for various purposes.

Izvestiya MGTU MAMI. 2021;15(4):60-72
pages 60-72 views

Modeling the work of the automotive differential with internal friction in the system for calculating the multi body dynamics

Chichekin I.V., Shuranova A.A.


The work is devoted to the operation of an automobile differential of suspended friction modeling in the system for calculating the dynamics of coupled bodies. The model was developed in the RecurDyn application for calculating the dynamics of rigid and deformable bodies from the FunctionBay company.

The aim of the work is to develop a mathematical model of the differential with friction washers and to confirm the adequacy of its operation. The developed mathematical model of the differential is tested for the possibility of its subsequent use in modeling the transmission of a vehicle in the calculating the dynamics of coupled bodies system. In this work, a model of the differential has been created and described in detail. The model was used for the analysis of kinematics and dynamics. Methods of modeling a simple symmetric differential and a self-locking one are shown based on one mathematical model. The well-known analytical dependences describing the kinematic and force laws of the ratio of angular velocities and torques between the output links and the differential housing are given. A method for calculating and modeling the friction torque in the differential was selected and described. An equation describing the frictional moment in the differential is presented.

A virtual test bench was developed and described. Afterwards it was used for differential operation simulation. Load modes that are equivalent to various driving conditions of a real automobile are selected, their quantitative parameters are given. In this work, the criteria for evaluating the performance of the differential model are selected. The results of modeling for all load modes are given. According to those results the adequacy of the developed mathematical model of the differential with friction washers is proved. The proposals on the use of the developed model are given.

Izvestiya MGTU MAMI. 2021;15(4):73-82
pages 73-82 views

Energy saving technologies and energy efficiency of motor transport power plants

Shabanov A.V., Vanin V.K., Yesakov A.E.


The perspective energy sources alternative to hydrocarbons, which are currently used in the world, are considered. Energy-saving technologies for the use of hydrocarbon fuel in vehicles are analyzed.

The need to develop the use of electric drives on automobiles is noted. The importance of systematical accumulation and analyzing of the existing experience of operating vehicles with electric drives abroad and in the Russian Federation is considered. Monitoring the technologies developed abroad and the problems arising during the operation of electric vehicles will make it possible to determine the priority ways of their development and to concentrate the efforts of researchers in the direction ensuring the maximum efficiency of their application.

One of the currently attractive and economically viable ways of developing road transport for domestic practice is the use of vehicles with hybrid power plants. It is shown that the production of hybrid vehicles and electric vehicles abroad is successfully developing and is nowadays one of the most dynamic in the world.

Indicators of efficiency of electric power consumption of vehicles with electric drive of various automobile manufacturers are given. A comparative analysis of technologies for the use of electric automobiles to improve the environmental situation in megalopolises is carried out and the problems of increasing the efficiency of automobile power plants are considered.

It is shown that the climatic conditions of the Russian Federation with long periods of low temperatures of atmospheric air strongly affect the energy losses associated with heating the passenger compartment, and to a large extent - on the energy efficiency of the power plant of electric vehicles.

To assess the efficiency of using electric vehicles, it is proposed to use a universal indicator of the efficiency of energy consumption. It is proposed to carry out a comparative assessment of the energy consumption of various vehicles by the energy parameter qEL.

The calculated data show that the use of vehicles with electric drive and, in particular, rechargeable hybrids is more profitable in comparison with the use of vehicles equipped exclusively with internal combustion engines.

Izvestiya MGTU MAMI. 2021;15(4):83-91
pages 83-91 views

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies