I am simulating mixing of 3 gases in a flow channel. I want to know the unit of concentration variable. I see that the total concentration of the three gases adds up to 1 at each point, so does it mean it is given in fraction?

Hello,

Thanks for posting your question to this forum! Is your question related to scFLOW or scSTREAM? If this is in the context of scFLOW, please see my answer below. 

You are correct, the concentration output is expressed as a fraction. 

In a mixed gas and chemical reaction analysis, we specify the species concentration described by mass fraction. Please refer to the solver guide for more details Solver Reference Guide>Input Format for scFLOWsolver>Command Data>PROPERTY command:



Similarly, in scPost, the Concentration output is the mass fraction of species, and the molar fraction is output as well. Both of these quantities are dimensionless as they are expressed in fractions. Please refer to the solver guide for more details. Solver Reference Guide>Input Format for scFLOWsolver>Command Data>VOUT command:



In terms of visualizing the location of maximum concentration of product, wouldn't the dimensionless concentration still be helpful to determine the location product formation? 

Thanks,

Rodrigo 

Hello,

Thanks for posting your question to this forum! Is your question related to scFLOW or scSTREAM? If this is in the context of scFLOW, please see my answer below. 

You are correct, the concentration output is expressed as a fraction. 

In a mixed gas and chemical reaction analysis, we specify the species concentration described by mass fraction. Please refer to the solver guide for more details Solver Reference Guide>Input Format for scFLOWsolver>Command Data>PROPERTY command:



Similarly, in scPost, the Concentration output is the mass fraction of species, and the molar fraction is output as well. Both of these quantities are dimensionless as they are expressed in fractions. Please refer to the solver guide for more details. Solver Reference Guide>Input Format for scFLOWsolver>Command Data>VOUT command:



In terms of visualizing the location of maximum concentration of product, wouldn't the dimensionless concentration still be helpful to determine the location product formation? 

Thanks,

Rodrigo