Implementation of DO Radiation in Ansys Fluent
I have been trying to implement the DO Radiation Model to simulate a radiation beam in Ansys Fluent since the past 1 month without much success. The computational domain consists of a cylinder of 10 cm radius and 1 m length and the front section of the cylinder is specified as irradiated wherein incident radiation enters the domain. Air and dust particles are present inside the cylinder.
I have set the absorptivity of air to zero in the simulation, and the theta and phi extent corresponding to the beam width is set to 1e-06. I have also set the theta and phi pixels and divisions equal to 15. I am expecting the incident radiation to be constant intensity over the entire domain, however, I what I am observing is that the intensity of incident radiation decreases with the axial length, and finally attains a constant value after a certain distance.
I would highly appreciate your support in solving the issue. Please let me know in case any additional information is required.