Wyniki wyszukiwania - BazTech

1

Numerical study of an unsteady non-premixed flame in a porous medium based on the thermal equilibrium model

Pakdee Watit, Sakkarangkoon Thammasathit

Journal of Theoretical and Applied Mechanics

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2021

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Vol. 59 nr 3

401–412

EN

The present research numerically investigates the non-premixed combustion of CH4 in a porous medium. The mathematical model proposed consists of conservation of mass, momentum, energy, and species equations. The discretized equations are integrated according to the third - order Runge - Kutta method. A porous medium is defined as a pseudohomogeneous medium. The proposed unsteady model is successfully validated with the published study. The model is able to describe physical behaviors of a non-premixed flame. The porous structure made of SiC gives higher temperature than when Al2O3 is used since SiC has higher thermal conductivity and lower heat capacity.

2

Numerical investigation of a novel burner to combust anode exhaust gases of SOFC stacks

Pianko-Oprych P., Jaworski Z.

Polish Journal of Chemical Technology

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2017

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Vol. 19, nr 3

20--26

EN

The aim of the present study was a numerical investigation of the efficiency of the combustion process of a novel concept burner under different operating conditions. The design of the burner was a part of the development process of a complete SOFC based system and a challenging combination of technical requirements to be fulfilled. A Computational Fluid Dynamics model of a non-premixed burner was used to simulate combustion of exhaust gases from the anode region of Solid Oxide Fuel Cell stacks. The species concentrations of the exhaust gases were compared with experimental data and a satisfactory agreement of the conversion of hydrocarbons was obtained. This validates the numerical methodology and also proves applicability of the developed approach that quantitatively characterized the interaction between the exhaust gases and burner geometry for proper combustion modelling. Thus, the proposed CFD approach can be safely used for further numerical optimisation of the burner design.

3

Numerical calculation of rotating detonation chamber

Shi Z., Kindracki J.

Journal of Power Technologies

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2017

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Vol. 97, nr 4

314--326

EN

ANSYS FLUENT 14 supplied the CFD tools used in the numerical calculation of rotating detonation combustion. During calculations, various fuel injection methods and configurations of combustion chamber were applied in an attempt to obtain stable and correct detonation propagation results in a separated fuel-air injection system (non-premixed combustion model). However, FLUENT was not originally designed for detonation combustion and the failure to achieve re-initiation of detonation after collision was always the core issue in the non-premixed combustion model. Thus, this paper mainly focuses on research into the behavior of stable continuously rotating detonation in premixed combustion cases. The analysis of stable continuously rotating detonation behaviors and structures was carried out with different boundary conditions and mesh cells. The pressures were measured by using a number of artificial sensors inserted near the chamber outside surface in various axial and/or circumferential directions. With those key results in the case of premixed combustion, we were able to comparably conclude that stable rotating detonation would also be generated if the refilling process were properly exhibited in non-premixed combustion. The paper finishes with evaluations and conclusions regarding general detonation behaviors and performances.

4

The numerical analysis of hydrogen combustion in chamber of aviation turbo engine

Jesionek K., Błoński D., Pospolita W.

Archivum Combustionis

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2017

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Vol. 37 nr 1

5--14

EN

The article presents the preliminary work on the adaptation of the combustion chamber of aviation turbo-shaft engine to supply it with hydrogen for ground energy generation purposes. Difficulties and problems of both design and operational matters for the use of hydrogen as a basic fuel have been presented. The paper presents mathematical formulation, boundary conditions and assumptions for the concept. With the use of ANSYS CFX commercial code a hydrogen combustion process for pre-optimized design of the burner has been simulated. The results are presented in the form of distributions of temperature, velocity and concentrations of individual components which were used to analyze the changes that have occurred in the combustion kinetics after using gaseous fuel. Results indicated the direction of further work on the optimization of processes occurring in the combustion chamber of the turbo-shaft engine.

5

Rotary Ramjet Engine - Numerical analysis of aerodynamics and combustion

Laube T., Piechna J., Müller N.

Archivum Combustionis

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2014

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Vol. 34 nr 2

129--154

EN

The results of numerical calculations of 2-D and 3-D flows and the combustion process in versions of an advanced rotational engine are presented and analysed. Based on the idea of the ramjet internal flow engine, the project of the rotary engine that generates torque on a shaft was developed and its operation analyzed. In the considered version of the rotary ramjet engine, a set of ramjet engines move around a center axis at high angular velocity to realize the supersonic airflow in their engine inlet. The only mowing part of the engine is a fast rotating disk with obliquely located channels near the external part of the disk forming ramjet engines. The channels in disk perform the functions of compressing the air, combusting the air fuel mixture, and generating thrust with the exhaust gases. The general principle of operation and performance of the rotary engine are discussed. Through the numerical solution of the steady averaged Navier-Stokes equations with k-ɛ turbulence model and non-premixed model of combustion, the basic characteristics of the flow and engine efficiency of the presented designs were predicted. The analysis focuses on the flow, combustion, and thermal challenges. Structural considerations are outside the scope of this paper. Results of the 2-D and 3-D simulations are presented in plots of pressure, fluid velocity, temperature, fuel and oxygen distribution.

6

Predykcja CFD procesów emisji zanieczyszczeń gazowych w wysokotemperaturowych komorach spalania

Bialik W., Gil S., Mocek P.

Czasopismo Techniczne. Środowisko

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2009

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R. 106, z. 3-Ś

3-12

PL

W artykule opisano zastosowanie metody objętości skończonych do wizualizacji 3d termokinetyki procesów spalania i tworzenia produktów reakcji w wysokotemperaturowej komorze spalania. Modelowano proces spalania metanu z wykorzystaniem prostego, 2-krokowego mechanizmu reakcji. Obliczenia przeprowadzono dla osiowosymetrycznej komory z palnikiem dyfuzyjnym typu rura w rurze.

EN

The application of finite volumes method to computer 3d visualization of thermo-kinetic combustion process and formation of reaction products in high temperature combustion chamber is presented in the paper. Basing on the standard two-steps mechanism of reaction has been modelled the methane combustion process. Computations have been carried out for the axial-symmetric chamber with double-pipe diffusion - type burner.