GeorgeChen92 said:Hi, I'm working on a project of coupled simulation involving MCNP and Fluent, and having trouble with how to apply the pseudo-material method in cross section handling. Is there any related material or tutorial? Or, does anyone know the procedure of applying the method and what kind of files the method actually modifies(e.g. xsdir or the material card in mcnp input file)?
Toast said:The pseudo-material method modifies the MCNP material card in the MCNP input file. One would change the number density of the entries to reach an approximate mixture of materials with the same cross section as the desired material.
Eg if you wanted Lithium at 500 degrees and only had cross sections at 400 and 600 then you would add a fraction of both the 400 and 600 degree cross section.
There is an equation for finding the fraction of materials to add when making the pseudo-material http://neams.rpi.edu/jiw2/papers/ANS 92 Conlin.pdf
Are you planning on using pseudo-materials to get cross sections for particular temperatures? If so perhaps look at on the fly doppler broadening instead
http://www.casl.gov/docs/Martin.OTF.MC2013.Final.pdf
However sorts of questions are often answered on the MCNP email forum
https://laws.lanl.gov/vhosts/mcnp.lanl.gov/mcnp_forum.shtml
The pseudo-material method is a mathematical and computational approach that is used to simulate the behavior of composite materials with complex microstructures. It involves creating a virtual material with properties that mimic the behavior of the real composite material.
The pseudo-material method is typically applied using numerical simulations, such as finite element analysis, where the virtual material is incorporated into the model. The method requires knowledge of the microstructure of the composite material and the properties of its constituent materials.
One of the main advantages of the pseudo-material method is its ability to accurately predict the behavior of complex composite materials without the need for costly and time-consuming experiments. It also allows for the exploration of different microstructures and material combinations to optimize the design of composite materials.
While the pseudo-material method is a powerful tool, it does have its limitations. It relies heavily on accurate inputs for the microstructure and material properties, which can be difficult to obtain. It also requires significant computational resources and expertise to implement.
The accuracy of the pseudo-material method is typically validated by comparing simulation results with experimental data. This can be done for simple material systems where experimental data is readily available. Additionally, sensitivity analyses can be performed to assess the impact of varying input parameters on the results.