Challenge on Combustion

AIM :- To study the Combustion Simulation and the effect of the addition of water content on the formation of NOx and soot.

OBJECTIVES :-

• Types of combustion simulations in FLUENT
• Perform a combustion simulation on the combustor model and write report on results.

PART-1 :-

Perform a combustion simulation on the combustor model and plot the variation of the mass fraction of the mass fraction of the different species in the simulation using line probes at different locations of the combustor as shown in figure. We need to plot for CO2, H2O, CH4, N2, O2, NOx emission and soot formation.

PART-2 :-

As we must have observed from the above simulation, the NOx and soot is getting formed at the outlet of the combustor. Such formation has harmful effects on the enviornment and humans. The stringent government norms also demand the least formation of NOx and soot and to satisfy those requirments, you need to check the effects of adding the water in the fuel.

In this part, we need to add the water content in the fuel from 5% to 30% by mole and observe the effect of it on the results. It is necessary to provide line plots and contours to prove your claim.

SOLUTIONS :-

# Types of combustion simulations in FLUENT :-

Models :-

Non-premixed combustion :-

In non premixed combustion, fuel and oxidizer enter the reaction zone in distinct streams. This is in contrast to premixed systems, in which reactantsare mixed at the molecular level before burning. Examples of non-premixed combustion include pulverized coal furnaces, diesel, internal combustion engines and pool fires. It enable the calculation of turbulent reacting flow. This is available only for turbulent flows using the pressure based solver.

Premixed combustion :-

In premixed combustion, fuel and oxidizer are mixed at the molecular level prior to ignition. Combustion occurs as a flame front propogating into the unburnt reactants. Example of premixed combustion incude aspirated internal combustion engines, lean premixed gas turbine combustors, and gas leak explosions. This is available only for turbulent flows using the pressure based solver.

The limitations apply to the premixed combustiuon model are -

1. We must use the pressure based solver. The premixed combustion model is not available with the density based solver.
2. The premixed combustion model is valid only for turbulent, subsonic flows. These types of flames are called deflagrations. Explosions also called detonations, where the combustible mixture is ignited by the heat behind a shock wave, can be modeled with the finite rate model using the density based solver.
3. The premixed combustion model cannot be used in conjunction with the pollutent (i.e. soot and NOx) models. However, a perfectly premixed system can be model with the partially premixed model, which can be used with the pollutant models.
4. You can not use the premixed combustion model to simulate reacting discrete phase particles, because these would result in a partially premixed system. Only inert particles can be used with the premixed combustion model.

Partially premixed combustion :-

This system are premixed flames with non uniform fuel oxidizer mixtures (equivalence ratios). Such flames include premixed jets discharging into a quiescent atmosphere, lean premixed combustors with diffusion pilot flames or cooling air jets, and imperfectly mixed inlets, it enable the partialy premixed turbulent combustion model. This is available only for turbulent flows using the pressre base solver. If you are interested in computing the concentrations of individual species in the domain, you can use the partially premixed model.

Limitations :-

• The underlying theory, assumption and limitations of the non premixed and premixed model apply directly to the partially premixe model. In particular, the single mixture fraction approach is limited to two inlet streams, which may be pure fuel, pure oxidizer. The two mixture fraction model extends the number of inlet streams to three, but incurs a majar computational overhead.
• The flamelet generated manifold (FGM) model is limited to the C-equation partially premixed model.

Phases :-

Volumetric :-

It is for gas phase reactions, the reaction rate is define on a volumetric basis enables the calculation of reacting flow using the finite rate formulations.

Wall surface :-

For gas phase reaction, the reaction rate is defined on a volumetric basis and the net rate of creation and distruction of chemical species becomes a source term in the species conservation equation. For surface reactions, the rate of adsorption and disorption is governed by both chemical kinetics and diffusion to and from the surface. Wall surface reaction therefore create source and sinks of chemical species in the gas phase, as well as on the reacting surface enable the calculation of wall surface reactions. This will appear only if volumetric is enabled.

Electrochemicals :-

An electro chemical charge transfer reaction is a chemical reaction between neutral species, charged ions and electrons, phenomenon is associated with electro chemically include batteries, fuel cells, corrosion and electro deposition. Charge transfer reaction occurs at phase interfaces between electrodes (i.e. anode or cathod) and an electrolyte. This interface is reffered to as Faradeic surface. The electrochemical reaction model is only implimented in the framework of single phase flow. Enables the calculations of electro chemical reactions. This appear only if Volumetric is enabled.

Below I explain both part in details by taking respected cases to prove and discuss more detail by giving examples and plots. For providing details I reffer respected research paper.

PART-1 :- In this part I adopted the following steps are-

1. As we have CAD model, and that is in 3D, if we study of that then we required lot of time and lot of steps with accuracy, but for avoding this I created 3D model to 2D model, because the 3D model is homogeneous and due to this if we study any part then by integrating we get whole geometry.
2. For converting 3D model to 2D model I put first plane then I got half geometry and then also I doing same process for another half geometry, Finally I got quarter geometry which is required geometry and then I share this same topology to the meshing.
3. In meshing I taken name of each side by respected naming and then I enable the proximity inside the sizing and consider element size equal to 1mm for better results and share to the setup.
4. In setup first off all I checking solution, then I enable the energy equation, then I use K-epsilon setup, then I enable the specis, NOx and soot model, create temperature, pressure and velocity contours as well as mass flow rate and total heat transfer rate plots, then I created boundary conditions, and create animation for temperatur contours for front view and run it upto 2500 iterations.
5. Finally in results I plotted contours, rendering ...etc.

Following are the detailing of the above procedures as-

# Perform a combustion simulation on the combustor model :-

Geometry :-

3D model of the combustor is provided for the simulation. In this cylinder, methane and air are mixed and combusted. Volume of air compared to fuel is very high. Also there have small gap between the two cylinders is the injection area.

Since, running the simulation for entire 3D geometry requires lot of time and powerful computer which is expensive. 3D model is transformed into a 2D model which is efficient and accurate to working and results.

Meshing :-

Meshing element size = 1mm

Total number of elements =67342

Total number of nodes = 136652

Base mesh is 1mm. In sizing, capture curvature and proximity are turned on. All traingle method is used, since default setting is quadrilaterals. A descent finer mesh is developed with the above settings.

CASE-setup :-

Solver :-steady-state, pressure based, absolute and axisymmetry.

Viscous model :- K-epsilon, standerd, standard wall treatment.

Zones :- air inlet velocity inlet = 0.5 m/s,

species for O2 = 0.23

Fuel inlet velocity inlet = 80 m/s,

specied for CH4 = 1

Since we are simulating the combustion we have to turn on the turbulence model to make the species and combustion related model to work. Models that are selected in the species are as are given pictures also. The eddy dessipation model, based on the work Magnussen and Hjertager, is a turbulent chemistry reaction model. Most fuels are fast burning and the overall rate of reaction is controlled by turbulence mixing. In this model, the chemical reaction is governed by large eddy mixing time scale. Combustion initiates whenever there is turbulence present in the flow. It does not need an ignition source to initiate the combustion.

1. Viscous model :-

2. Momentum at air inlet :-

3. Species at air inlet :-

4. thermal proparty at air inlet :-

5. Cell zone :-

6. CH4 chart :-

This chart proves that the at inlet methane air is dicharge and then converge with constant value of temperature and we get stable value at each point by increasing values of \'Y\'.

7. CH4 mass fraction at rendering :-

8. CH4 mass fraction contour at air inlet :-

9. CH4 mass fraction contour at fuel inlet :-

10. Ch4 mass fraction gradient :-

methane air mass fraction gradient value at rendering increases from air and fuel inlet and upto some distance it shows gradient values.

11. CO2 chart :-

At inlet carbon di oxide value changes and towards outlet it remains stable as shown in figure.

12. CO2 mass fraction at rendering :-

13. CO2 mass fraction contour at air inlet :-

14. CO2 mass fraction contour at fuel inlet :-

15. CO2 mass fraction gradient :-

At fuel inlet rate of carbon di oxide increases and then stable some while.

16. Edit materials :-

Here selecting the required material from fluent database, proparties are given below by default.

17. Momentum at fuel inlet :-

At fuel inlet always velocity is maximum and I consider 80 m/s which 140 times than air inlet velocity.

18. Species at fuel inlet :-

At fuel inlet methane air vaqlues must be unity because there have no any mixture, if therre have any mixture then methane air value must be decreases and increases adding material quantity, only keep in mind is that the sum of species of mass fraction must be equal to 1.

19. Thermal proparties at fuel inlet :-

At fuel and air inlet temperature value must be equal to 300 kelvin.

20. General model :-

Here selecting pressure based solver and steady state time with Planer space for required efficiency of combustion.

21. H2O chart :-

This is the chart for water content in the combustions.

22. H2O mass fraction :-

23. H2O mass fraction gradient :-

24. Hybrid initialization :-

25. Initialize solution :-

Here provide all required mass fraction values.

26. Mass flow rate plot :-

27. Mass flow rate values :-

This is the value for mass flow rate.

28. N2 chart :-

29. N2 mass fraction :-

30. NOx model :-

For NOx model we must required thermal and prompt NOx but any more it depends on us by selecting combustion chemical

31. O2 chart :-

The value of air (i.e. O2) increases with \'Y\' distance.

32. Pressure contour values :-

maximum pressure contours =2268.048 Pa

Minimum pressure contours =-33.89858 Pa

33. Pressure volume rendering :-

34. Scaled residuals :-

This is the scaled residuals which shows developed and stable combustions.

35. Solution control :-

a.

b.

This is the solution control for all chemicals including polutent.

36. Solution method :-

Here showing solution methods which is used for solutions.

37. Soot chart :-

38. Soot mass fraction :-

39. Soot model :-

Here I consider one-step soot model, and remaining settings are by default.

40. Species model :-

In species model I use Species transport model, then used Volumetric reaction with non-Explicit source chemistry solver by enabeling Inlet diffusion and diffusion energy source. Mixture proparties is methane air and eddy dissipation turbulence chemistry Interactions.

41. Temperature animation :-

42. Temperature chart :-

43. Temperature contour value :-

44. Temperature probe ;-

Here I use probe at different location for finding temperature values, and I shows it increases from inlet to outlet.

45. Temperature vectors at air inlet :-

46. Temperature volume rendering :-

47. Total heat transfer rate :-

48. Total heat transfer rate plot :-

This plot shows that the total heat transfer rate values which is at start decreases and then stable drastically.

49. Total heat transfer rate values :-

Here shown total heat transfer rate values.

50. Total pressure contours :-

Here shown total pressure value at fuel inlet is high and every where is constant

51. Total temperature contours :-

52. Total temperature contour plot :-

53. Velocity contour values :-

54. Velocity contours :-

55. Velocity vectors at air inlet :-

56. Velocity vectors at fuel inlet :-

57. Velocity volume rendering :-

58. Report file :-

59. CH4 vs Y- chart :-

[Name]
Series 1 at /LINE:Line 1

[Data]
Y [ m ],Ch4.Mass Fraction
0.00000000e+00, 9.09930587e-01
1.00000005e-03, 8.49080563e-01
2.00000009e-03, 7.31298566e-01
3.00000003e-03, 6.17349505e-01
4.00000019e-03, 5.04630148e-01
4.99999989e-03, 3.95311177e-01
6.00000005e-03, 2.90411830e-01
7.00000022e-03, 1.91116586e-01
8.00000038e-03, 1.02782317e-01
8.99999961e-03, 4.07184735e-02
9.99999978e-03, 1.67649556e-02
1.09999999e-02, 2.02802941e-02
1.20000001e-02, 2.89827976e-02
1.30000003e-02, 3.36187631e-02
1.40000004e-02, 3.66397649e-02
1.49999997e-02, 3.92633826e-02
1.60000008e-02, 4.17161435e-02
1.70000009e-02, 4.40405682e-02
1.79999992e-02, 4.62438837e-02
1.89999994e-02, 4.83265072e-02
1.99999996e-02, 5.02882823e-02
2.09999997e-02, 5.21297045e-02
2.19999999e-02, 5.38519025e-02
2.30000000e-02, 5.54563478e-02
2.40000002e-02, 5.69445901e-02
2.50000004e-02, 5.83180711e-02
2.60000005e-02, 5.95779605e-02
2.70000007e-02, 6.07251115e-02
2.80000009e-02, 6.17599972e-02
2.89999992e-02, 6.26827255e-02
2.99999993e-02, 6.34930581e-02
3.09999995e-02, 6.41904399e-02
3.20000015e-02, 6.47740513e-02
3.29999998e-02, 6.52427971e-02
3.40000018e-02, 6.55954629e-02
3.50000001e-02, 6.58306852e-02
3.59999985e-02, 6.59469813e-02
3.70000005e-02, 6.59428537e-02
3.79999988e-02, 6.58008158e-02
3.90091613e-02, 6.55253977e-02
4.00265455e-02, 6.51231781e-02
4.10470515e-02, 6.45935833e-02
4.20750305e-02, 6.39130250e-02
4.31065187e-02, 6.31836653e-02
4.41401973e-02, 6.22572787e-02
4.51621003e-02, 6.10888638e-02
4.57070358e-02, 6.04359135e-02
4.61841822e-02, 5.98752685e-02
4.71957512e-02, 5.84866926e-02
4.81957532e-02, 5.70075884e-02
4.91957515e-02, 5.54160327e-02
5.01957498e-02, 5.37079051e-02
5.11957519e-02, 5.18889949e-02
5.21957502e-02, 4.99648713e-02
5.31957522e-02, 4.79411222e-02
5.41957505e-02, 4.58236635e-02
5.51957525e-02, 4.36190069e-02
5.61957508e-02, 4.13345732e-02
5.71957529e-02, 3.89787108e-02
5.81957512e-02, 3.65608707e-02
5.91957532e-02, 3.40918191e-02
6.01957515e-02, 3.15840617e-02
6.11957498e-02, 2.90522594e-02
6.21957518e-02, 2.65136212e-02
6.31957501e-02, 2.39882842e-02
6.41957521e-02, 2.14992967e-02
6.51957542e-02, 1.90725848e-02
6.61957487e-02, 1.67367589e-02
6.71957508e-02, 1.45218307e-02
6.81957528e-02, 1.24575160e-02
6.91957548e-02, 1.05720507e-02
7.01957494e-02, 8.88898596e-03
7.11957514e-02, 7.42314896e-03
7.21957535e-02, 6.17881166e-03
7.31957480e-02, 5.14737749e-03
7.41957501e-02, 4.30860510e-03
7.51957521e-02, 3.63240577e-03
7.61957541e-02, 3.08115617e-03
7.71957487e-02, 2.61649792e-03
7.81957507e-02, 2.20516301e-03
7.91957527e-02, 1.82308443e-03
8.01957548e-02, 1.45861553e-03
8.11957493e-02, 1.11380883e-03
8.21957514e-02, 7.94817868e-04
8.31957534e-02, 4.98849724e-04
8.41957480e-02, 2.14160973e-04
8.51957500e-02, 7.28069426e-05


[Name]
Series 2 at /LINE:Line 2

[Data]
Y [ m ],Ch4.Mass Fraction
0.00000000e+00, 6.24487340e-01
1.00000005e-03, 6.24398708e-01
2.00000009e-03, 6.24138474e-01
3.00000003e-03, 6.23723030e-01
4.00000019e-03, 6.23177052e-01
4.99999989e-03, 6.22530520e-01
6.00000005e-03, 6.21814847e-01
7.00000022e-03, 6.21060550e-01
8.00000038e-03, 6.20294631e-01
8.99999961e-03, 6.19540334e-01
9.99999978e-03, 6.18816376e-01
1.09999999e-02, 6.18136942e-01
1.20000001e-02, 6.17512405e-01
1.30000003e-02, 6.16949856e-01
1.40000004e-02, 6.16452932e-01
1.49999997e-02, 6.16023242e-01
1.60000008e-02, 6.15659833e-01
1.70000009e-02, 6.15360856e-01
1.79999992e-02, 6.15122676e-01
1.89999994e-02, 6.14940941e-01
1.99999996e-02, 6.14810705e-01
2.09999997e-02, 6.14726663e-01
2.19999999e-02, 6.14683390e-01
2.30000000e-02, 6.14675462e-01
2.40000002e-02, 6.14697576e-01
2.50000004e-02, 6.14744723e-01
2.60000005e-02, 6.14812732e-01
2.70000007e-02, 6.14897192e-01
2.80000009e-02, 6.14994407e-01
2.89999992e-02, 6.15101576e-01
2.99999993e-02, 6.15215719e-01
3.09999995e-02, 6.15334809e-01
3.20000015e-02, 6.15456820e-01
3.29999998e-02, 6.15580320e-01
3.40000018e-02, 6.15704000e-01
3.50000001e-02, 6.15826845e-01
3.59999985e-02, 6.15948081e-01
3.70000005e-02, 6.16067410e-01
3.79999988e-02, 6.16183996e-01
3.90103050e-02, 6.16298914e-01
4.00218181e-02, 6.16411030e-01
4.10465859e-02, 6.16520941e-01
4.20784168e-02, 6.16628289e-01
4.31074053e-02, 6.16732001e-01
4.39427719e-02, 6.16813302e-01
4.41440083e-02, 6.16832793e-01
4.51715551e-02, 6.16928697e-01
4.61852290e-02, 6.17020071e-01
4.71957512e-02, 6.17107749e-01
4.81957532e-02, 6.17191553e-01
4.91957515e-02, 6.17272377e-01
5.01957498e-02, 6.17350161e-01
5.11957519e-02, 6.17425025e-01
5.21957502e-02, 6.17497206e-01
5.31957522e-02, 6.17566705e-01
5.41957505e-02, 6.17633462e-01
5.51957525e-02, 6.17697775e-01
5.61957508e-02, 6.17759526e-01
5.71957529e-02, 6.17818952e-01
5.81957512e-02, 6.17875993e-01
5.91957532e-02, 6.17931008e-01
6.01957515e-02, 6.17983699e-01
6.11957498e-02, 6.18034363e-01
6.21957518e-02, 6.18083179e-01
6.31957501e-02, 6.18129790e-01
6.41957521e-02, 6.18174851e-01
6.51957542e-02, 6.18217766e-01
6.61957487e-02, 6.18259072e-01
6.71957508e-02, 6.18298590e-01
6.81957528e-02, 6.18336618e-01
6.91957548e-02, 6.18372917e-01
7.01957494e-02, 6.18407726e-01
7.11957514e-02, 6.18441045e-01
7.21957535e-02, 6.18472874e-01
7.31957480e-02, 6.18503153e-01
7.41957501e-02, 6.18532062e-01
7.51957521e-02, 6.18559599e-01
7.61957541e-02, 6.18585765e-01
7.71957487e-02, 6.18610501e-01
7.81957507e-02, 6.18633986e-01
7.91957527e-02, 6.18655860e-01
8.01957548e-02, 6.18676305e-01
8.11957493e-02, 6.18695021e-01
8.21957514e-02, 6.18711710e-01
8.31957534e-02, 6.18725955e-01
8.41957480e-02, 6.18778408e-01
8.51957500e-02, 6.18824601e-01


[Name]
Series 3 at /LINE:Line 3

[Data]
Y [ m ],Ch4.Mass Fraction
0.00000000e+00, 6.19535089e-01
1.00000005e-03, 6.19535089e-01
2.00000009e-03, 6.19534850e-01
3.00000003e-03, 6.19534612e-01
4.00000019e-03, 6.19534254e-01
4.99999989e-03, 6.19533777e-01
6.00000005e-03, 6.19533181e-01
7.00000022e-03, 6.19532466e-01
8.00000038e-03, 6.19531751e-01
8.99999961e-03, 6.19530857e-01
9.99999978e-03, 6.19529903e-01
1.09999999e-02, 6.19528890e-01
1.20000001e-02, 6.19527817e-01
1.30000003e-02, 6.19526684e-01
1.40000004e-02, 6.19525492e-01
1.49999997e-02, 6.19524300e-01
1.60000008e-02, 6.19523048e-01
1.70000009e-02, 6.19521737e-01
1.79999992e-02, 6.19520485e-01
1.89999994e-02, 6.19519055e-01
1.99999996e-02, 6.19517744e-01
2.09999997e-02, 6.19516313e-01
2.19999999e-02, 6.19515002e-01
2.30000000e-02, 6.19513571e-01
2.40000002e-02, 6.19512260e-01
2.50000004e-02, 6.19510829e-01
2.60000005e-02, 6.19509518e-01
2.70000007e-02, 6.19508266e-01
2.80000009e-02, 6.19507015e-01
2.89999992e-02, 6.19505882e-01
2.99999993e-02, 6.19504571e-01
3.09999995e-02, 6.19503379e-01
3.20000015e-02, 6.19502246e-01
3.29999998e-02, 6.19501173e-01
3.40000018e-02, 6.19500101e-01
3.50000001e-02, 6.19499147e-01
3.59999985e-02, 6.19498193e-01
3.70000005e-02, 6.19497359e-01
3.79999988e-02, 6.19496524e-01
3.90000008e-02, 6.19495630e-01
4.00139131e-02, 6.19494796e-01
4.10431623e-02, 6.19494200e-01
4.20755334e-02, 6.19493425e-01
4.22392711e-02, 6.19493365e-01
4.31196876e-02, 6.19492829e-01
4.41486165e-02, 6.19492114e-01
4.51728664e-02, 6.19491637e-01
4.61865366e-02, 6.19491100e-01
4.71965894e-02, 6.19490623e-01
4.81961481e-02, 6.19490206e-01
4.91952598e-02, 6.19489849e-01
5.01934774e-02, 6.19489551e-01
5.11899069e-02, 6.19489193e-01
5.21917716e-02, 6.19488895e-01
5.31842411e-02, 6.19488716e-01
5.41870072e-02, 6.19488537e-01
5.51909283e-02, 6.19488358e-01
5.61907440e-02, 6.19488120e-01
5.71957529e-02, 6.19488060e-01
5.81957512e-02, 6.19487941e-01
5.91957532e-02, 6.19487941e-01
6.01957515e-02, 6.19487822e-01
6.11957498e-02, 6.19487822e-01
6.21957518e-02, 6.19487882e-01
6.31957501e-02, 6.19487882e-01
6.41957521e-02, 6.19487822e-01
6.51957542e-02, 6.19487941e-01
6.61957487e-02, 6.19487941e-01
6.71957508e-02, 6.19488060e-01
6.81957528e-02, 6.19488180e-01
6.91957548e-02, 6.19488299e-01
7.01957494e-02, 6.19488358e-01
7.11957514e-02, 6.19488418e-01
7.21957535e-02, 6.19488597e-01
7.31957480e-02, 6.19488776e-01
7.41957501e-02, 6.19488776e-01
7.51957521e-02, 6.19489014e-01
7.61957541e-02, 6.19489193e-01
7.71957487e-02, 6.19489312e-01
7.81957507e-02, 6.19489431e-01
7.91957527e-02, 6.19489551e-01
8.01957548e-02, 6.19489610e-01
8.11957493e-02, 6.19489849e-01
8.21957514e-02, 6.19489908e-01
8.31957534e-02, 6.19490087e-01
8.41957480e-02, 6.19490623e-01
8.51957500e-02, 6.19491220e-01

This is the value for methane air and \'Y\' value for all three lines.

60. Animation file :-

PART-2 :-

Fro above results we can see that all poisonus gas are collected at outlet, that are very dengerous and poissonus because that are pure due to no mixture of any extra quantity like water, but due to government norms we want to decrease this poissoning quantity and hence we need to add some water content in fuel in small ratio from 5% to 30%.

I considering total three cases here by varying water ratio in the fuel, so that decrease the purety of poissoning gasses. Below are the total explaination with plot I proove it.

CASE-1 :-

1. 10% water added in fuel inlet :-

For maintaining mass fraction equal to unity I use methane air as 0.9 and water quantity is 0.1.

2. Mass flow rate :-

3. Mass flow rate values :-

Here shows mass flow rate values.

4. Pressure contour :-

5. Scaled residuals :-

6. Temperature contours :-

7. Total heat transfer rate :-

8. Total heat transfer rate values :-

Here shows lower total heat transfer rate values.

9. Total pressure contours :-

10. Total pressure plot :-

11. Total temperature contours :-

12. Velocity contours :-

13. Velocity plot :-

14. velocity contours :-

Velocity is increases at fuel inlet from higher to lower because at start velocity is igher then it slows down with respect to time.

15. XY- plot :-

a.

b.

c.

CASE-2 :-

1. 20% water added in fuel inlet :-

2. CH4 contour at fuel inlet :-

3. CO2 contour at fuel inlet :-

4. H2O contour at fuel inlet :-

5. Mass flow rate :-

6. N2 contour at fuel inlet :-

7. O2 contour at fuel inlet :-

8. Pressure contour at fuel inlet :-

9. Scaled residuals :-

10. Soot contour at fuel inlet :-

11. temperature contour at fuel inlet :-

12. Total heat transfer rate :-

13. Total temperature contours :-

14. Velocity contours at fuel inlet :-

CASE-3 :-

1. 30% water added in fuel inlet :-

2. CH4 fuel inlet contour :-

3. CO2 fuel inlet contour :-

4. H2O fuel inlet contour :-

5. Mass flow rate :-

6. Mass flow rate values :-

7. N2 fuel inlet contour :-

8. O2 fuel inlet contour :-

9. Pressure fuel inlet contour :-

10. Scaled residuals :-

11. Soot fuel inlet contour :-

12. Temperature fuel inlet contour :-

13. Total heat transfer rate :-

14. Total heat transfer rate values :-

15. Total temperature contours :-

16. Velocity contour at Fuel inlet :-

RESULTS :-

From above all three cases we can say that if water quantity is added into the fuel then the rate of poissonus gases decreases at specific range. Upto specific quantity of water mixture in fuel poissonus gasses are decreases at great range. Also plotted line and contour to proven decreases the quantity of poisonus gasses.

Water quantity decrease down the concentration of poissinus gasses, the mixture of water and air are beneficial only when they are mixed in exact ratios. The density of water is more than the poissonus gasses and hence, it not be fly in atmosphere as easy as possible. Also I calculated mass flow rate and total heat transfer rate values for each cases.

CONCLUSIONS :-

From above explainations and plotting I can conclude that-

1. Combustion done without the fuel source using the eddy dissipation model. This model uses turbulence model to create combustion.
2. When there is enough turbulence mixing of fuel and air, eddy dissipation model consider it as reaction and creates combustion depending on the amount of mixture present in that cell.
3. Temperature, CO2 and H2O has similar kind of contour, which tells us that this species mass fraction depends on the effective combustion.
4. NOx is present in a very low mass fraction which is quite neglegible.
5. NOx concentration generated in combustion systems are generally low. As a result, NOx chemistry has negligible influence on the predicted flow field, temperature and major combustion product concentrations. It follows that the most efficient way to use the NOx model is as a post processor to the main combustion calculations.

In this way I proved that how water ratio in fuel decreases the hazardousness and conclude that which factor are depends and get disturbance in that. So I completed this challenge successfully.