# [Q] Inintial condition in multiphase, multicomponent problem.

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 May 11, 2015, 05:10 [Q] Inintial condition in multiphase, multicomponent problem. #1 Member   Jinwhan Ryuk Join Date: Feb 2013 Location: South Korea Posts: 91 Rep Power: 13 I am calculating CFBC(Circulating Fluidized Bed Combustion) problem. I modified this problem as multi component multiphase problem by using CFX Tutorial, coal combustion. Unfortunately, Because of muticomponent mutiphase condition I cannot set initial volume fraction of sand in the boiler. I did not set combustion yet. I solve flow first and move to combustion. Does anyone give me a piece of advice how to do this?

 May 11, 2015, 05:53 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,746 Rep Power: 143 What is stopping you set the sand volume fraction initial condition?

 May 11, 2015, 21:03 #3 Member   Jinwhan Ryuk Join Date: Feb 2013 Location: South Korea Posts: 91 Rep Power: 13 Error #001100279 has occurred in subroutine ErrAction. Massage: The particle mass fractions have to add up to a total of one with a tolerance of 1%. The sum of the user specified values exceeds this threshold. <-This message came up independent of initial condition when particle calculatin begins.

 May 12, 2015, 06:47 #4 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,746 Rep Power: 143 So doesn't the error message tell you exactly what is wrong? A good way forward is to set one phase to be initial value: Automatic so then it automatically calculates a value which makes the total volume fractions sum to 1.

 May 14, 2015, 00:06 #5 Member   Jinwhan Ryuk Join Date: Feb 2013 Location: South Korea Posts: 91 Rep Power: 13 I found error and fix it temporarily. I changed Discrete Partticle Diameter Distribution to specified Diameter. The error has gone. Every particle(Limestone, coal, sand)has particle size distribution and mass fraction. Maybe I put wrong Mass Fraction List or Number Fraction list. I made Mass Fraction List sum be 1 indivisually. Do we have to think all componet mass fraction(calculated one component individual mass fraction/total component mass fraction)? But I am not confident about setting Number Fraction List according to mass fraction list. I put the same fraction to make sum 1.Perhaps it caused the error, I think. Thank you very much ghrrocks.