hello,
I would like help to write a matlab for solving the convection-diffusion equation of a compound in a 3D annular reactor (diffusion in two directions r and teta with convective transport in the main direction, see figure below) with a reaction on the surface of inner cylinder. The elements of the problem are as follows:

a 3D model is proposed. This model is based on a convection / radial diffusion principle in the annular space of the reactor. The mass balance in the gas phase can be written (eq. (1)):
(1)

0 < z < L
Inlet concentration : C0=4.5 10-5 mol.m-3
Where r is radial coordinate (m), z is axial coordinate, u is flow velocity (m s-1) and C, is the concentration of NCl3 (mol m-3).
The model takes the velocity profile developed in the annular space into account, as expressed by the following relationship:
(2)
With
(3)
z=1m
Um=0.5m s-1
ri=0.04m, the internal radius
re=0.05m, the external radius of reactor (m).
Boundary conditions are:
at the inner surface of the external cylinder, r=re:
(4)
at the catalyst surface, r=ri,
(5)
Where rp is the photocatalytic rate (mol m-2 s-1).
(6)
I=9.8 W m-2, n =1, kp = 2.6×10-6 mol s-1 W-1and Kp = 3x103m3 mol-1.
and for and

Thank you very much for your helphello,
I would like help to write a matlab for solving the convection-diffusion equation of a compound in a 3D annular reactor (diffusion in two directions r and teta with convective transport in the main direction, see figure below) with a reaction on the surface of inner cylinder. The elements of the problem are as follows:

a 3D model is proposed. This model is based on a convection / radial diffusion principle in the annular space of the reactor. The mass balance in the gas phase can be written (eq. (1)):
(1)

0 < z < L
Inlet concentration : C0=4.5 10-5 mol.m-3
Where r is radial coordinate (m), z is axial coordinate, u is flow velocity (m s-1) and C, is the concentration of NCl3 (mol m-3).
The model takes the velocity profile developed in the annular space into account, as expressed by the following relationship:
(2)
With
(3)
z=1m
Um=0.5m s-1
ri=0.04m, the internal radius
re=0.05m, the external radius of reactor (m).
Boundary conditions are:
at the inner surface of the external cylinder, r=re:
(4)
at the catalyst surface, r=ri,
(5)
Where rp is the photocatalytic rate (mol m-2 s-1).
(6)
I=9.8 W m-2, n =1, kp = 2.6×10-6 mol s-1 W-1and Kp = 3x103m3 mol-1.
and for and

Thank you very much for your help hello,
I would like help to write a matlab for solving the convection-diffusion equation of a compound in a 3D annular reactor (diffusion in two directions r and teta with convective transport in the main direction, see figure below) with a reaction on the surface of inner cylinder. The elements of the problem are as follows:

a 3D model is proposed. This model is based on a convection / radial diffusion principle in the annular space of the reactor. The mass balance in the gas phase can be written (eq. (1)):
(1)

0 < z < L
Inlet concentration : C0=4.5 10-5 mol.m-3
Where r is radial coordinate (m), z is axial coordinate, u is flow velocity (m s-1) and C, is the concentration of NCl3 (mol m-3).
The model takes the velocity profile developed in the annular space into account, as expressed by the following relationship:
(2)
With
(3)
z=1m
Um=0.5m s-1
ri=0.04m, the internal radius
re=0.05m, the external radius of reactor (m).
Boundary conditions are:
at the inner surface of the external cylinder, r=re:
(4)
at the catalyst surface, r=ri,
(5)
Where rp is the photocatalytic rate (mol m-2 s-1).
(6)
I=9.8 W m-2, n =1, kp = 2.6×10-6 mol s-1 W-1and Kp = 3x103m3 mol-1.
and for and

Thank you very much for your help convection_diffusin model, annular reactor 3d MATLAB Answers — New Questions

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