[Kenzhia3310]

Hi, there.
I am doing the premixed laminar flame recently.
When I was dealing with constant velocity of air-fuel inlet velocity (0.35m/s), it works perfectly fine.
However, when I applied parabolic inlet velocity with max speed of 0.35 m/s, it becomes something like this
0.35 ms UDF(axial-velo), 60%CH4-40%CO2, 298K, 500 iterations.JPG

The radius of my air-fuel inlet is 3.775 mm, and the co-flow inlet is formed by pure nitrogen with 0.05m/s.
Here is my output velocity profile:
((fuel_air_inlet_fluid_flow__fluent__ point 38)
(x
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
)
(y
0.0037253289
0.0036259866
0.0035266448
0.0034273025
0.0033279606
0.0032286183
0.0031292764
0.0030299341
0.0029305923
0.00283125
0.0027319081
0.0026325658
0.0025332235
0.0024338816
0.0023345393
0.0022351975
0.0021358551
0.0020365133
0.0019371711
0.0018378289
0.0017384868
0.0016391447
0.0015398026
0.0014404606
0.0013411185
0.0012417763
0.0011424342
0.0010430921
0.00094375003
0.00084440788
0.0007450658
0.00064572366
0.00054638158
0.00044703949
0.00034769735
0.00024835527
0.00014901315
4.9671053e-05
)
(axial-velocity
0.009026316
0.027078947
0.044409472
0.061386317
0.07796526
0.093851581
0.10938421
0.12448947
0.13893157
0.15301999
0.16665158
0.17964947
0.19229369
0.20445158
0.21600527
0.22720526
0.23788947
0.24799895
0.25775474
0.26696527
0.27563053
0.2839421
0.29167894
0.29890001
0.30576736
0.31203052
0.31780738
0.32323053
0.32802001
0.33235264
0.33633158
0.33964738
0.34253579
0.34507054
0.34691262
0.34835684
0.34944737
0.34981579
)
)

Is that any problem in my parabolic velocity profile?

[vinerm]

The profile you have is correct. The contours are of temperature, hence, not a validation of the profile. You should look at velocity contours and plot the profiles at various axial locations. Temperature and velocity contours will look same only when they have same boundary condition, which is not the case here. Default and most appropriate condition for velocity is no slip, i.e., 0 velocity at the wall. However, default for temperature is adiabatic, i.e., the gradient is 0 not the value. So, the field is expected outcome.