Non-reacting CFD analysis of a drop tube furnace used for solid fuel combustion

Gülenç, Gamze
In this thesis, the flow inside the drop tube furnace (DTF) which was already built in the Clean Combustion Technologies Laboratory located in Department of Mechanical Engineering at Middle East Technical University is analysed by using Computational Fluid Dynamics method. DTF is a semi-pilot scale electrically heated reactor with the aim of achieving constant temperature zone to investigate combustion characteristics of solid fuels. A simplified geometry is created for the flow analysis inside the DTF. The heating zone of the reactor is heated up to 1273 K and total air volumetric rate entering the inlets of the furnace is 10 L/min for the analyses conducted in the thesis. Natural convection governs the flow inside the furnace. Three different turbulence models (Standard k-ε, Realizable k-ε and SST k-ω) are employed in order to obtain velocity magnitudes and temperature distribution in the DTF. Transient solution is used for the simulation in which SST k-ω model is utilized to achieve convergence. The results are compared to analysis results in literature and temperature measurements performed. The analyses using k-ε models provide more similar trends with analysis results in literature and measurements. Constant temperature zone is achieved with k-ε models. Furthermore, gravitational effect is investigated. In the analysis where gravitational effect is neglected, the air continues to flow through the whole reactor with the declining velocity from 0.3 m/s to 0.1 m/s. However, in reality, the flow is stagnant at the exit of the heating zone, and the flow is maintained using a vacuum pump.


OZTURK, Emre; Tarı, İlker (2007-12-01)
In this study, Computational Fluid Dynamics, which has taken its position in the thermal design of electronic packages, was used in order to draw a CFD road map for forced cooling conjugate heat transfer analyses in heat generating electronic systems. The main sources of error in CM analyses arise from inappropriate numerical models including turbulence models, radiation modeling and discretization schemes, insufficient grid resolution, and lack of convergence. A complete computer chassis model with heat si...
Application of numerical shape optimization to the runner blades of a francis turbine
Yalılı, Mehmet; Aksel, Mehmet Haluk; Department of Mechanical Engineering (2015)
The multi-objective design of hydraulic turbines using computational fluid dynamics software has been an important subject in turbomachinery area recently. Researches focus especially on obtaining higher turbine efficiency by the improvement of runner shapes. Thus in the present study, a multi-objective shape optimization procedure was applied to improve the runner blade shapes of a small Francis turbine named as GAMM turbine which was selected from the literature. CFD computations as well as blade generati...
Incompressible flow simulations using least squares spectral element method on adaptively refined triangular grids
Akdağ, Osman; Sert, Cüneyt; Department of Mechanical Engineering (2012)
The main purpose of this study is to develop a flow solver that employs triangular grids to solve two-dimensional, viscous, laminar, steady, incompressible flows. The flow solver is based on Least Squares Spectral Element Method (LSSEM). It has p-type adaptive mesh refinement/coarsening capability and supports p-type nonconforming element interfaces. To validate the developed flow solver several benchmark problems are studied and successful results are obtained. The performances of two different triangular ...
Design and analysis of a vertical axis water turbine for river applications using computational fluid dynamics
Demircan, Eren; Aksel, Mehmet Haluk; Pınarcıoğlu, Mehmet Melih; Department of Mechanical Engineering (2014)
The main purpose of this study is to design a Darrieus rotor type vertical axis water turbine using Computational Fluid Dynamics (CFD) in order to be used in river currents. The CFD modeling is based on two dimensional numerical solution of the rotor motion using commercial Unsteady Reynolds Averaged Navier-Stokes solvers, Ansys Fluent and CFX. To validate the two dimensional numerical solution, an experimental Darrieus rotor type water turbine from literature is studied and performance of several turbulenc...
Computational fluid dynamics simulation of the combustion process, emission formation and the flow field in an in-direct injection diesel engine
Barzegar, Ramin; Shafee, Sina; Khalilarya, Shahram (National Library of Serbia, 2013)
In the present paper, the combustion process and emission formation in the Lister 8.1 in-direct injection diesel engine have been investigated using a computational fluid dynamics code. The utilized model includes detailed spray atomization, mixture formation and distribution model which enable modeling the combustion process in spray/wall and spray/swirl interactions along with flow configurations. The analysis considers both part load and full load states. The global properties are presented separately re...
Citation Formats
G. Gülenç, “Non-reacting CFD analysis of a drop tube furnace used for solid fuel combustion,” M.S. - Master of Science, Middle East Technical University, 2017.