scholarly journals Setting up the mathematical model of gas fuel combustion taking into account computational domain geometry refinement

2020 ◽  
Vol 13 (1) ◽  
pp. 60-72
Author(s):  
Y.A. Mitrofanova ◽  
R.A. Zagitov ◽  
P.V. Trusov
Keyword(s):  
Mathematical Model ◽  
Fuel Combustion ◽  
Computational Domain ◽  
Gas Fuel ◽  
The Mathematical Model

Parametric Analysis of a PULSCO Vent Silencer

2014 ◽  
Author(s):  
Usama Tohid ◽  
Chris Genger ◽  
John Kaiser ◽  
Ilaria Accorsi ◽  
Arturo Pacheco-Vega
Keyword(s):  
Mathematical Model ◽  
Parametric Study ◽  
Numerical Results ◽  
Operating Conditions ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Computational Domain ◽  
Hole Size ◽  
Plane Wave Solution ◽  
The Mathematical Model

We have conducted a parametric study via numerical simulations of a PULSCO vent silencer. The overall objective is to demonstrate the existence of an optimum system performance for a given set of operating conditions i.e., temperature, pressure, mass flow-rate and the working fluid, by modifying the corresponding geometry of the device. The vent silencer under consideration consists of a perforated diffuser, the silencer body and a tube module. The tube module consists of a set of tubes through which the working fluid passes. The flow tubes are perforated and surrounded with acoustic packing that is responsible for the attenuation. The mathematical model of the vent silencer is built upon Helmholtz equation for the plane wave solution, and the Delany-Bazley model for the acoustic packing. The geometrical parameters chosen for the parametric study include: the porosity of the diffuser and the flow tubes, the type of packing material used for the tube module, bulk density for the acoustic packing and the hole diameter of the perforated diffuser and flow tubes. The equations of the mathematical model are discretized over the computational domain and solved with a finite element method. Numerical results in terms of transmission loss, for the system, indicate that diffuser hole size of 1/4” with porosity of 0.1, flow tube hole size of 1/8” with porosity of 0.23, packing density of 16 kg/m3 for TRS-10 and 100 kg/m3 for Advantex provided the optimum results for the chosen set of conditions. The numerical results were found to be in agreement with experimental data.

scholarly journals The mathematical model of non-certified fuel combustion

2014 ◽  
Vol 2 (8(68)) ◽  
pp. 44
Author(s):  
Татьяна Сергеевна Добровольская ◽  
Максим Витальевич Максимов ◽  
Вадим Феликсович Ложечников ◽  
Андрей Владимирович Бондаренко
Keyword(s):  
Mathematical Model ◽  
Fuel Combustion ◽  
The Mathematical Model

Fuel Flexibility at Ignition Conditions for Industrial Gas Turbines

2013 ◽  
Author(s):  
Anders Larsson ◽  
Anton Berg ◽  
Alessio Bonaldo
Keyword(s):  
Mathematical Model ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Inert Gases ◽  
Ignition Energy ◽  
Minimum Ignition Energy ◽  
Fuel Flexibility ◽  
Start Up ◽  
Gas Fuel ◽  
The Mathematical Model

The variety of gaseous fuels that Siemens Industrial Turbomachinery (SIT) is requested to consider during sales enquiries has prompted product development projects that have allowed to continuously increase gas turbine fuel flexibility. The fuel flexibility often has to be guaranteed at all engine load conditions including ignition. The gas turbine ignition capabilities have therefore been analyzed in order to assess the engines current capabilities and identify further potentials. The authors’ approach for ignition fuel flexibility has been to model the minimum ignition energy (MIE) required for successful ignition and to validate the model by experiments conducted under test conditions reproducing engine start up flows at a combustion test rig. The experiments were performed using two hydrocarbon gases individually mixed with two inert gases at various concentrations. The mathematical model predicting the minimum ignition energy is applicable also to hydrocarbon and inert gases mixtures that were not used during the experimental campaign. The model was studied and developed in order to produce a tool for support of gas fuel enquiries received during the sales phase. In accordance to the predictions of the mathematical model, the experimental validation in the paper shows that the difference in MIE required to ignite the gas fuel composition depends on the inert gas used as well as the hydrocarbon used. The MIE model showed the capability of assessing if a specific gas composition can be used as a reliable start-up fuel.

Experimental and Numerical Investigations on Traveling Charge Gun Using Liquid Fuels

2011 ◽  
Vol 78 (5) ◽  
Author(s):  
Xin Lu ◽  
Yanhuang Zhou ◽  
Yonggang Yu
Keyword(s):  
Mathematical Model ◽  
Experimental Results ◽  
Liquid Fuels ◽  
Numerical Code ◽  
Computational Domain ◽  
Operating Pressure ◽  
Two Phase ◽  
Muzzle Velocity ◽  
Adaptive Grid Generation ◽  
The Mathematical Model

The traveling charge (TC) concept is theoretically capable of producing higher muzzle velocities without a large increase in maximum operating pressure, compared with the conventional charge. This work presents experimental and numerical studies on a 35 mm test gun system using liquid fuels as traveling charge. Eight firings with 2 different configurations of booster charge and traveling charge are performed in this paper. The firing experimental results indicate that the liquid traveling charge configuration performs better, in terms of increased muzzle velocity, than a conventional propellant charge by approximately 94 m/s, corresponding to about 8% velocity increase. A mathematical model for the two-phase flows in the 35 mm test gun system using liquid fuels as traveling charge is established and simulated by using the two-phase flow method and computational fluid dynamics technology. The mathematical model for the two-phase gas-dynamical processes consists of a system of first-order, nonlinear coupled partial differential equations. An adaptive grid generation algorithm is developed to account for the expansion of the computational domain due to the motion of the system’s payload in the tube. The numerical code is well validated by comparing its predictions with the experimental results. The calculated pressure-time profiles and projectile muzzle velocity are in good agreement with the experimental data. The numerical results show that the mathematical model developed gives the correct trend and can provide useful calculated parameters for the structural design of liquid traveling charge.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

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.

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

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.

RESEARCH OF INDICATORS OF A VEHICLE WITH A DIESEL WORKING ON DIESEL AND DIESEL GAS CYCLES USING THE MATHEMATICAL MODEL

2020 ◽  
pp. 14-19
Author(s):  
Serhii Kovbasenko ◽  
Andriy Holyk ◽  
Serhii Hutarevych
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
Environmental Performance ◽  
Energy Performance ◽  
Dual Fuel ◽  
Fuel System ◽  
Compressed Natural Gas ◽  
Diesel Vehicles ◽  
Diesel Cycle ◽  
The Mathematical Model

The features of an advanced mathematical model of motion of a truck with a diesel engine operating on the diesel and diesel gas cycles are presented in the article. As a result of calculations using the mathematical model, a decrease in total mass emissions as a result of carbon monoxide emissions is observed due to a decrease in emissions of nitrogen oxides and emissions of soot in the diesel gas cycle compared to the diesel cycle. The mathematical model of a motion of a truck on a city driving cycle according to GOST 20306-90 allows to study the fuel-economic, environmental and energy indicators of a diesel and diesel gas vehicle. The results of the calculations on the mathematical model will make it possible to conclude on the feasibility of converting diesel vehicles to using compressed natural gas. Object of the study – the fuel-economic, environmental and energy performance diesel engine that runs on dual fuel system using CNG. Purpose of the study – study of changes in fuel, economic, environmental and energy performance of vehicles with diesel engines operating on diesel and diesel gas cycles, according to urban driving cycle modes. Method of the study – calculations on a mathematical model and comparison of results with road tests. Bench and road tests, results of calculations on the mathematical model of motion of a truck with diesel, working on diesel and diesel gas cycles, show the improvement of environmental performance of diesel vehicles during the converting to compressed natural gas in operation. Improvement of environmental performance is obtained mainly through the reduction of soot emissions and nitrogen oxides emissions from diesel gas cycle operations compared to diesel cycle operations. The results of the article can be used to further develop dual fuel system using CNG. Keywords: diesel engine, diesel gas engine, CNG

Glycemia monitoring

1998 ◽  
Vol 2 ◽  
pp. 23-30
Author(s):  
Igor Basov ◽  
Donatas Švitra
Keyword(s):  
Diabetes Mellitus ◽  
Mathematical Model ◽  
Numerical Methods ◽  
Differential Equations ◽  
Blood Sugar ◽  
Self Regulation ◽  
Physiological System ◽  
Non Linear ◽  
The Mathematical Model

Here a system of two non-linear difference-differential equations, which is mathematical model of self-regulation of the sugar level in blood, is investigated. The analysis carried out by qualitative and numerical methods allows us to conclude that the mathematical model explains the functioning of the physiological system "insulin-blood sugar" in both normal and pathological cases, i.e. diabetes mellitus and hyperinsulinism.

Mathematical Models of Papermaking

2001 ◽  
Vol 6 (1) ◽  
pp. 9-19 ◽  
Author(s):  
A. Buikis ◽  
J. Cepitis ◽  
H. Kalis ◽  
A. Reinfelds ◽  
A. Ancitis ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Initial Value Problems ◽  
Moisture Transfer ◽  
Bound Water ◽  
Drying Process ◽  
Initial Value ◽  
First Order ◽  
Heat And Moisture ◽  
The Mathematical Model ◽  
The Web

The mathematical model of wood drying based on detailed transport phenomena considering both heat and moisture transfer have been offered in article. The adjustment of this model to the drying process of papermaking is carried out for the range of moisture content corresponding to the period of drying in which vapour movement and bound water diffusion in the web are possible. By averaging as the desired models are obtained sequence of the initial value problems for systems of two nonlinear first order ordinary differential equations. 

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