Numerical Study of Forced MHD Convection Flow and Temperature Around Periodically Placed Cylinders

In this paper we consider 2D stationary boundary value problems for the system of magnetohydrodynamic (MHD) equations and the heat transfer equation. The viscous electrically conducting incompressible liquid moves between infinite cylinders with square or round sections placed periodically. We also consider similar 2D MHD channel flow with periodically placed obstacles on the channel walls. We analyse the 2D forced and free MHD convection flow and temperature around cylinders and obstacles in homogeneous external magnetic field. The cylinders, obstacles and walls of the channel with constant temperature are heated. The distributions of electromagnetic fields, forces, velocity and temperatur…

Numerical study of electrodynamic control of straw co-firing with propane

Galīgo elementu metodes pielietošana eliptiskām Dirihlē un Neimana robežproblēmām

Darbā tiek apskatīts vispārīgais otrās kārtas eliptisks diferenciāloperators divās dimensijās, iegūts Dirihlē un Neimana robežproblēmu vispārinātais formulējums un definēts vispārināta atrisinājuma jēdziens. Ir pamatota tāda veida atrisinājuma telpas izvēle un vispārināta formulējuma korektība. Galīgo elementu metode, balstīta uz šo formulējumu, pielietota dažām vienkāršākām Dirihlē un Neimana robežproblēmām.

Mathematical modelling and experimental study of straw co-firing with gas using electric field control of combustion characteristics

Parameter optimization and pattern recognition for combustion and reaction kinetics applications

Promocijas darbā ir aplūkoti vienkāršotie degšanas modeļi un aprakstīti dažādi ķīmisko reakciju mehānismi. Šo problēmu atrisinājumi tika iegūti, pielietojot galīgo elementu metodi. Tajā pašā laikā ir izmēģināti daži modeļa dimensijas reducēšanas paņēmieni. Modelēšanas rezultāti tika salīdzināti ar eksperimentālajiem datiem, veicot modeļu parametru optimizāciju. Optimizācijas metodes izveidotie paterni ir saglabāti diskrētās dinamiskās sistēmas nekustīgo punktu formā. Šos punktus izmanto, pakāpeniski mainot eksperimentālos datus. Atslēgvārdi: degšana, reakciju kinētika, matemātiskā modelēšana, galīgo elementu metode, PSO optimizācija, dimensijas reducēšana, paternu atpazīšana.

On numerical simulation of electromagnetic field effects in the combustion process

This paper deals with a simplified model taking into account the interplay of compressible, laminar, axisymmetric flow and the electrodynamical effects due to Lorentz force’s action on the combustion process in a cylindrical pipe. The combustion process with Arrhenius kinetics is modelled by a single step exothermic chemical reaction of fuel and oxidant. We analyze non-stationary PDEs with 6 unknown functions: the 3 components of velocity, density, concentration of fuel and temperature. For pressure the ideal gas law is used. For the inviscid flow approximation ADI method is used. Some numerical results are presented.

Magnetic Field Control of Combustion Dynamics

Abstract Experimental studies and mathematical modelling of the effects of magnetic field on combustion dynamics at thermo-chemical conversion of biomass are carried out with the aim of providing control of the processes developing in the reaction zone of swirling flame. The joint research of the magnetic field effect on the combustion dynamics includes the estimation of this effect on the formation of the swirling flame dynamics, flame temperature and composition, providing analysis of the magnetic field effects on the flame characteristics. The results of experiments have shown that the magnetic field exerts the influence on the flow velocity components by enhancing a swirl motion in the …

Cilindru virknes aptecēšanas matemātiskais modelis

Darbā tiek apskatīts bezgalīgas cilindru virknes aptecēšanas stacionārais uzdevums mag- nētiskā lauka iedarbībā divās dimensijās. Viskoza nesaspiežama šķidruma plūsmu ap- raksta Psī-Zēta sistēma. Iegūtas attiecīgo eliptisko robežproblēmu vājās nostādnes un uzkonstruēts iterāciju process, katrā solī pielietojot galīgo elementu metodi. Atslēgas vārdi: MHD, Navjē-Stoksa vienādojumi, psī-zēta sistēma, galīgo elementu me- tode

Development of combustion dynamics at co-combustion of straw with wood

On obtaining numerical solutions for some reacting flow problems by using different matlab tools

Influence of electric field on thermo-chemical conversion of mixtures of straw pellets with coal

Mathematical modelling and experimental study of straw co-firing with gas

The main goal of the present study is to promote a more effective use of agriculture residues (straw) as an alternative renewable fuel for cleaner energy production with reduced greenhouse gas emissions. With the aim to improve the main combustion characteristics at thermo-chemical conversion of wheat straw, complex experimental study and mathematical modelling of the processes developing when co-firing wheat straw pellets with a gaseous fuel were carried out. The effect of co-firing on the main gasification and combustion characteristics was studied experimentally by varying the propane supply and additional heat input into the pilot device, along with the estimation of the effect of co-firing on…