how to define argon'diffuse coefficient?
 

hi everyone, i am modeling argon gas'transport problem.nozzle 'diameter is 8mm,its outlet'speed is 30m/s in order to protect from plate oxidization.the plate is heated in air.the nozzle inclination angle with regard to the horizontal line is 45 degrees.argon gas is transported to a space with air fully.

i want to know argon'coverage size on the plate.how to define argon'diffuse coefficient? what about their pressure out'condition?