Week 10 - Simulating Combustion of Natural Gas.
Aim:
1. Perform a combustion simulation on the combustor model and plot the variation of the mass fraction of the different species’ in the simulation using line probes at different locations of the combustor.
2. In this part, you need to add the water content in the fuel from 5% to 30% by mole and observe the effect of it on the results.
Combustion:Non-premixed combustion
Model: eddy dissipiation model.
Fuel: Methane
Geometry:
1)2D axisymmetric diagram of combuster consists of Air inlet and fuel inlet
Meshing:
Named selection:
1)axis
2)Fuel inlet
3)Air inlet
4)Walls
5)Wall side
6)Outlet
Meshing:
1)Refinedmesh of elementsize=1.6mm
2)switch capture proximity with 3 defult num cells
3)Stastics
1)General
2)Models
3) species model
4)Nox model
5)Soot model
6)Boundary conditions
7)Molefraction of oxygen
8)Fuel inlet velocity
9)fuel inlet without addition ofh2o
Residuals:
Mole fraction of species
Post processing:
Plots of Ch4:
Plots of co:
Plots of co2:
Plots of h2o :
Plots of N2:
Plots of o2:
Plots of No pollutants :
Plots of soot:
Part2:
Table1:
| h20 | ch4 |
| 0.05 | 0.95 |
| 0.1 | 0.9 |
| 0.15 | 0.85 |
| 0.2 | 0.8 |
| 0.25 | 0.75 |
| 0.3 | 0.7 |
Case1: (h2o=0.1,ch4=0.9)
Residuls:
Mass fraction:
Mole fraction:
Contours:
Temperature contour:
Mass fraction of ch4:
Mass fraction of o2:
Mass fraction ofco2:
Mass fraction of co:
Mass fraction of h20:
Mass fraction of N2:
soot:
Post processing:
Plots of ch4
Plots of co :
Plots of co2:
Plots of N2:
plots of o2 :
Plots of No pollutants:
Plots of soot :
Case2: (h2o=0.2,ch4=0.8)
Residuals:
Massfraction:
Mole fraction:
Temperature contour:
Mass fraction of ch4:
Massfraction of o2:
Massfraction of co2:
Massfraction of co:
Massfraction of h20:
Massfraction of N2:
Soot:
NOx:
Post processing:
line probes at different locations of the combustor as shown
Plot for ch4emission:
plot for CO Emission:
Plot for Co2 emission:
Plot for N2 Emission:
Plot for o2 emissions:
Plot for NOPollutants:
Plot for soot:
Case2: (h2o=0.25,ch4=0.75)
Residuals:
Molefraction:
Temperature contour:
Massfraction ofch4:
Massfraction ofo2:
Massfraction of co2:
Massfraction of co:
Massfraction of h2o:
Massfraction of n2:
mass of pollutants(nox):
soot:
Plots for ch4:
Plots for CO:
Plots for CO2:
Plots for h2o:
Plots for NO Pollutants:
Plots for N2:
Plots for o2:
Plots for soot:
Observations:
Case1:
| water content(10%) | |
| Spieces | mass fraction |
| ch4 | 0.001347069 |
| o2 | 0.17088412 |
| co2 | 0.052765159 |
| co | 0.000477031 |
| h20 | 0.046414298 |
| n2 | 0.72811232 |
| noX | 0.000149107 |
| soot | 2.842E-14 |
Case2:
| water content(20%) | |
| Spieces | mass fraction |
| ch4 | 0.000959862 |
| o2 | 0.17873188 |
| co2 | 0.047494822 |
| co | 0.000340621 |
| h20 | 0.044505347 |
| n2 | 0.72796747 |
| noX | 0.0000804 |
| soot | 2.346E-14 |
Case3:
| water content(30%) | |
| Spieces | mass fraction |
| ch4 | 0.000654725 |
| o2 | 0.18694063 |
| co2 | 0.041948049 |
| co | 0.000232437 |
| h20 | 0.042378111 |
| n2 | 0.72784606 |
| noX | 0.00005549 |
| soot | 1.831E-14 |
Graphs:
Soot formations:
Emissions of soot and Nox are formed at outer portion of combuster which are very harmful to enviornment in this cases on addition of water. With addition of water percentage to fuel emissions of Nox get decreases and emissions of soot also get decreases