scholarly journals Modelling Methodology of Piston Pneumatic Air Engine Operation

2019 ◽  
Vol 13 (4) ◽  
pp. 271-278
Author(s):  
Dariusz Szpica ◽  
Michal Korbut

Abstract The article presents a mathematical model describing the operation of a piston pneumatic air engine. Compressed air engines are an alternative to classic combustion solutions as they do not directly emit toxic exhaust components. In the study, a modified internal combustion piston engine was adopted as pneumatic engine. The mathematical model was divided on the two subsystems, that is, mechanical and pneumatic. The mechanical subsystem describes a transformation of compressed air supply process parameters to energy transferred to the piston and further the conversion of the translational to rotary motion; in turn, in the pneumatic part, the lumped elements method was used. Calculations were carried out using the Matlab-Simulink software, resulting in the characteristics of external and economic indicators. The presented mathematical model can be ultimately developed with additional elements, such as the intake or exhaust system, as well as timing system control.

1991 ◽  
Vol 113 (1) ◽  
pp. 27-29 ◽  
Author(s):  
E. Belardinelli ◽  
M. Ursino ◽  
G. Fabbri ◽  
A. Cevese ◽  
F. Schena

In the present paper pressure changes induced by sudden body acceleration are studied “in vivo” on the dog and compared to the results obtainable with a recently developed mathematical model. A dog was fixed to a movable table, which was accelerated by a compressed air piston for less than 1 s. Acceleration was varied by changing the air pressure in the piston. Pressure was measured during the experiment at different points along the vascular bed. However, only data obtained in the carotid artery and abdominal aorta are presented here. The results demonstrated that impulse body accelerations cause significant pressure peaks in the vessel examined (about + 25 mmHg in the carotid artery with body acceleration of g/2). Moreover, pressure changes are rapidly damped, with a time constant of about 0.1s. From the present results it may be concluded that, according to the prediction of the mathematical model, body accelerations such as those occurring in normal life can induce pressure changes well beyond the normal pressure value.


2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Qihui Yu ◽  
Yan Shi ◽  
Maolin Cai

A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine.


2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Qihui Yu ◽  
Maolin Cai ◽  
Yan Shi ◽  
Chi Yuan

To eliminate the pollutants exhausting, this paper presents an idea of using compressed air as the power source for engines. Instead of an internal combustion (IC) engine, this automobile is equipped with a compressed air engines (CAEs), which transforms the energy of the compressed air into mechanical kinematic energy. Through analysis of the working process of a CAE, the mathematical model is setup. Experiments are carried out to verify the engine performance and the basic model’s validity. By selecting the appropriate reference values, the mathematical model is transformed to a dimensionless expression. The dimensionless speed and efficiency characteristics of the CAE are obtained. Through analysis, it can be obtained that the dimensionless average rotating speed is mainly determined by the intake duration angle, the dimensionless inertia parameter, the dimensionless exhaust pressure, and the scale factor of exhaust valve. Moreover, the efficiency of the CAE is mainly determined by the dimensionless exhaust pressure, the intake duration angle and the dimensionless cylinder clearance. This research can be referred to in the design of CAE and the study on optimization of the CAE.


2018 ◽  
Vol 18 (1) ◽  
pp. 5-10
Author(s):  
Helga Silaghi ◽  
Maria Gamcova ◽  
Andrei Marius Silaghi ◽  
Viorica Spoială ◽  
Alexandru Marius Silaghi ◽  
...  

Abstract An electric vehicle (EV) uses an electric motor for traction and chemical batteries, superconductors, combustion cells and / or inertial masses as energy sources. To avoid problems regarding the accuracy of the mathematical model of the system, the use of artificial intelligence in electric drives is a viable alternative. Among other advantages of using artificial intelligence in the electric drive system, it can be emphasized that its application reduces the design time and leads to avoiding problems with the introduction of the mathematical model in the system control algorithm. This paper presents several case studies of electrical vehicles and some considerations about intelligent control of EVs. Finally some experimental results that compare classical control system with fuzzy logic control system for EV are presented.


Author(s):  
Paolo Casoli ◽  
Luca Riccò ◽  
Federico Campanini ◽  
Antonio Lettini ◽  
Cesare Dolcin

This paper presents the multibody mathematical model of a hydraulic excavator, developed in the AMESim® environment, which is able to predict the machinery fuel consumption during the working cycles. The mathematical modelling approach is presented as well as the subsystems models. The experimental activity on the excavator is presented in detail. The excavator fuel consumption was measured according to the JCMAS standard. The working cycles were executed an appropriate number of times in order to minimize the stochastic influence of the operator on the fuel consumption. The results show the mathematical model capability in the machine fuel consumption prediction. The excavator model could be useful either to perform accurate analyses on the energy dissipation in the system, giving the possibility to introduce new system configurations and compare their performance with the standard one, or for the definition of novel system control strategies in order to achieve the fuel consumption reduction target.


2022 ◽  
Vol 36 (06) ◽  
Author(s):  
NGUYEN MINH PHU ◽  
LE THANH DANH

DPF is an important device in the exhaust system of Diesel engine. In this paper we simulate velocity and pressure distributions in DPF to determine kinematic and hydraulic characteristics. This will provide the basis for designing and selecting size of channels in DPF. Numerical simulations were made using ANSYS Fluent commercial software and OpenFOAM open-source software. The results show that the difference between the two softwares is negligible. A compact 1D mathematical model developed based on the Darcy equation, momentum equation and continuity equation. The mathematical model solved by shooting method for boundary value problem. Simulation results from 1D and 3D approaches are very coincident.


Author(s):  
Carlo Ferraresi ◽  
Walter Franco ◽  
Giuseppe Quaglia

The deformable fluid actuators available on the market, i.e. pneumatic muscles and pneumatic springs, are designed to mainly exert compressive or tensile forces. This paper deals with a novel fluid deformable actuator, with three membranes, called BiFAc3, whose particular feature is the ability to exert both tensile and compressive forces. The structure of the actuator is based on three cylindrical coaxial nonisotropic membranes connected to two end plates, whose original shape allows the independent supply of the three internal chambers. The first part of the paper deals with the internal structure and the geometry of the actuator, describes the operating principle and presents a prototype. The second part presents a modelling methodology that can be used to design and analyse the actuator in dynamic applications. The mathematical model of the actuator is based on three different levels of complexity which correspond to three consecutive design stages. The model has been experimentally validated: it is a useful tool for the choice of the actuator’s geometrical dimensions, in order to satisfy specific applicative requirements.


2020 ◽  
Vol 1 (3) ◽  
pp. 75-82
Author(s):  
D.V. Pavlov ◽  
◽  
K.Yu. Platonov ◽  
R.N. Khmelev ◽  
◽  
...  

At present, the most effective method for studying internal combustion engines (ICE) is mathe-matical modeling and computational experiment. The use of a computational experiment can signif-icantly reduce material and time costs in the research, design and refinement of the internal combus-tion engine. At the same time, despite the high level of the applied mathematical models, there are practically no studies aimed at establishing the regularities of the influence of the state of the cylin-der-piston group (CPG) on the crankcase gas consumption and other indicators of engine operation at steady-state and transient modes. This article is devoted to solving an urgent problem associated with the development of a theoretical base that provides a comprehensive simulation of steady-state and transient modes of diesel engine operation, taking into account the consumption of crankcase gases. The article presents a mathematical model of a diesel engine based on thermal mechanics, which reflects the main features of the engine as a system that converts energy in time. The system of equations of the mathematical model is based on the laws of conservation of energy, mass, equa-tions of motion of solid links and includes differential equations for the rates of change in the tem-perature and density of the working fluid in the cylinder and in the crankcase of the internal com-bustion engine, the ideal gas equation of state, as well as differential equations for the change in the angular speed and angle of motor shaft rotation. The mathematical model is tested on the example of a small-sized single-cylinder diesel engine 1Ch9.5 / 8.0 with air cooling. This type of engine is widely used for small-scale mechanization in agriculture, generator sets, etc. The article presents the results of calculations of a number of engine operating modes in comparison with the results of field tests carried out at the test bench.


Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.


Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.


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