How to simulate a passive scaler transport?
 

Hi, I want to acquire concentration profile(concentration gradient) iodine injected into blood within left coronary artery, here iodine is the passive scaler and I only need to consider advection diffusion through blood i.e. non-reactive process.
Here boundary conditions that are applied for blood flow are:
1) No slip boundary condition at artery wall,
2) Pulsatile velocity and pressure profile at inlet and outlet respectively, using udf.

I am confused how to define the passive scaler or which module should I use : CFX or Fluent, what should I use multiphase or multispecies or user defined scaler or 'the species option in fluent'. how do I define the source of the scaler what mole fraction should I use?

Thank you in advance.