Numerical Investigation Into the Effect of Air Swirl on Non-Premixed Combustion

2021 ◽  
Author(s):  
Anuj B ◽  
G Mahesh Nayak ◽  
Yogesh B ◽  
Saravanan B
Keyword(s):  
Heat Transfer ◽  
Radiation Heat Transfer ◽  
Flame Temperature ◽  
Tangential Velocity ◽  
Ansys Fluent ◽  
Air Inlet ◽  
Turbulent Characteristics ◽  
Swirl Intensity ◽  
Dissipation Model ◽  
One Step

Abstract Endeavour is made to investigate the effect of swirled air on methane-air combustion in a Harwell combustor geometry. The inlet air swirl intensity on combustion characteristics such as temperature, pollutant formation, and flow dynamics is studied. The modeling of turbulent characteristics is performed with the standard K–ε model using ANSYS Fluent. Eddy dissipation model with one step reaction is used for modeling chemical reaction and P-I radiation model for radiation heat transfer. The swirl number is achieved in the range of 0.0 to 0.6, by varying the tangential velocity to the air inlet. With the increase in swirl intensity, the maximum flame temperature drops, and most of the flame formation shifts towards the inlet of the furnace. The change in the flow field is aided by the formation of recirculating bubbles. The swirl causes the flame to spread radially away from the axis, thereby increasing the heat transfer flux to the furnace wall. As a result, a significant reduction in the formation of NO pollutants is observed.

Radiation Heat Transfer Environment in Fire and Furnace Tests of Radioactive Materials Packages

2009 ◽  
Author(s):  
Allen C. Smith
Keyword(s):  
Heat Transfer ◽  
Radiation Heat Transfer ◽  
Flame Temperature ◽  
Hydrocarbon Fuel ◽  
Radiation Environment ◽  
Radiation Heat ◽  
Radioactive Materials ◽  
Fire Event ◽  
Fire Environment ◽  
Accident Conditions

The Hypothetical Accident Conditions (HAC) sequential tests of radioactive materials (RAM) packages includes a thermal test to confirm the ability of the package to withstand a transportation fire event. The test specified by the regulations (10 CFR 71) consists of a 30 minute, all engulfing, hydrocarbon fuel fire, with an average flame temperature of at least 800°C. The requirements specify an average emissivity for the fire of at least 0.9, which implies an essentially black radiation environment. Alternate tests which provide equivalent total heat input at the 800°C time averaged environmental temperature may also be employed. When alternate tests methods are employed, such as furnace or gaseous fuel fires, the equivalence of the radiation environment may require justification. The effects of furnace and open confinement fire environments are compared with the regulatory fire environment, including the effects of gases resulting from decomposition of package overpack materials. The results indicate that furnace tests can produce the required radiation heat transfer environment, i.e., equivalent to the postulated pool fire. An open enclosure, with transparent (low emissivity) fire does not produce an equivalent radiation environment.

Effect of Swirl Intensity on the Heat Performance of a Premixed Circular Impinging Flame Jet With Swirl Induced

2005 ◽  
Author(s):  
X. Q. Huang ◽  
C. W. Leung ◽  
C. K. Chan
Keyword(s):  
Heat Transfer ◽  
Flame Temperature ◽  
Small Scale ◽  
Uniform Heat Flux ◽  
Swirl Ratio ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Swirl Angle ◽  
Swirl Intensity ◽  
Impinging Flame

Swirl has been successfully introduced to a small scale premixed circular impinging flame jet under low Reynolds number. The study on the flow and heat transfer characteristics of such a swirling impinging flame found that it could provide a more uniform heat flux and flame temperature distribution around the stagnation point. The swirl ratio, which is indicated by swirl angle and axial velocity at the exit of the nozzle is changed to investigate the effect of swirling intensity on the heat performance of the flame jet.

Numerical investigation of heat transfer effects on combustion in a generic gas turbine burner

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ender Hepkaya ◽  
Nuri Yucel
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Turbulence Modeling ◽  
Radiation Heat Transfer ◽  
Flame Temperature ◽  
Reacting Flow ◽  
Transfer Effects ◽  
Content Type ◽  
Thermal Boundary Conditions ◽  
Heat Transfer Effects

Purpose This study aims to methodologically investigate heat transfer effects on reacting flow inside a liquid-fueled, swirl-stabilized burner. Furthermore, particular attention is paid to turbulence modeling and the results of Reynolds-averaged Navier–Stokes and large eddy simulation approaches are compared in terms of velocity field and flame temperature. Design/methodology/approach Simulations consist liquid fuel distribution using Eulerian–Lagrangian approach. Flamelet-Generated Manifold combustion model, which is a mixture fraction-progress variable formulation, is used to obtain reacting flow field. Discrete ordinates method is also added for modeling radiation heat transfer effect inside the burner. As a parametric study, different thermal boundary conditions namely: adiabatic wall, constant temperature and heat transfer coefficient are applied. Because of the fact that the burner is designed for operating with different materials, the effects of burner material on heat transfer and combustion processes are investigated. Additionally, material temperatures have been calculated using 1 D method. Finally, soot particles, which are source of luminous radiation in gas turbine combustors, are calculated using Moss-Brookes model. Findings The results show that the flow behavior is obviously different in recirculation region for both turbulence modeling approach, and this difference causes change on flame temperature distribution, particularly in the outer recirculation zone and region close to swirler. In thermal assessment of the burner, it is predicted that material of the burner walls and the applied thermal boundary conditions have significant influence on flame temperature, wall temperature and flow field. The radiation heat transfer also makes a strong impact on combustion inside the burner; however, luminous radiation arising from soot particles is negligible for the current case. Originality/value These types of burners are widely used in research of gas turbine combustion, and it can be seen that the heat transfer effects are generally neglected or oversimplified in the literature. This parametric study provides a basic understanding and methodology of the heat transfer effects on combustion to the researchers.

Analysis of Different Radiation Models in a Swirl Stabilized Combustor

2014 ◽  
Author(s):  
Aayush K. Sharma ◽  
Chandrachur Bhattacharya ◽  
Swarnendu Sen ◽  
Achintya Mukhopadhyay ◽  
Amitava Datta
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Computational Study ◽  
Radiation Heat Transfer ◽  
Three Dimensional ◽  
Numerical Data ◽  
Ansys Fluent ◽  
Wall Functions ◽  
Radiation Modelling ◽  
Model Gas Turbine Combustor

A computational study on spray combustion, using kerosene (C12H23) as fuel, in a model gas turbine combustor has been carried out. The numerical modelling of radiation heat transfer is carried out in a three-dimensional swirl stabilized, liquid-fuelled combustor. The Favre-averaged governing equations are solved using Ansys Fluent 14.5 as the CFD package. The turbulence parameters are computed using realizable k-ε with standard wall functions model. Eulerian-Lagrangian approach is used to track stochastically the motion of the evaporation species in the continuous gas phase. The effect of different radiation models — Discrete Ordinate (DO), P1 and Discrete Transfer Radiation Model (DTRM) along with Soot are analysed in the present study. To validate the results of radiation modelling carried out in the present work, the computational results have been compared with previous experimental data for the same combustor geometry. The numerical data considering effect of soot along with radiation is shown to closely approximate the experimental data. An attempt has also been made to introduce a liner in the combustor and evaluate its effect and the heat transfer across the liner for the present numerical model.

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