boundary conditions

uday · November 14, 2009, 01:04

Iam simulating intake manifold of a twin cylinder diesel engine. Boundary conditions for outlet of the manifold is time(CA) dependent.I have pressures at every CA.
My auestion is how to give these boundary conditions to the manifold.
By writing UDF s we can give the B.C which are varing with respective to a equation but how to give these pressures at different CA which are varying with out any relation.
Plese give me suggetions in this matter.
Thanks in advance.

patiltushar123 · November 14, 2009, 05:49

First, convert the b.c.s of pressure values at diff crank angles in to perssure values at diff. time instant.VIZ. for 2400 rpm, u might be having pressure values at diff CAs, then knowing rpm, convert them to P at diff time instants....apply that as a profile in fluent and then select b.c.s.If u dont know how to write b.c.s follow the manuls from Fluent.

uday · November 15, 2009, 00:51

Thanku for u r suggesion, i will try to do it.

uday · November 16, 2009, 06:50

I tried but iam not finding how to give these pressure values at different times(CA) with out writing udf.

uday · November 17, 2009, 00:08

Good morning friends,

Iam simulating inlet manifold.For outlet of the manifold iam giving unsteady B.C using transient data file.
Here two parameters are there one is time and another one is pressure.

Now my question is how to divide this time parameter means in which(how much difference) steps i have to give. Please give me suggestion in this matter.

Thanks in advance.

November 14, 2009, 01:04	boundary conditions	#1
uday Member uday Join Date: Sep 2009 Posts: 38 Rep Power: 17	Iam simulating intake manifold of a twin cylinder diesel engine. Boundary conditions for outlet of the manifold is time(CA) dependent.I have pressures at every CA. My auestion is how to give these boundary conditions to the manifold. By writing UDF s we can give the B.C which are varing with respective to a equation but how to give these pressures at different CA which are varying with out any relation. Plese give me suggetions in this matter. Thanks in advance.

November 14, 2009, 05:49	B.C.s	#2
patiltushar123 New Member Tushar Join Date: Mar 2009 Posts: 9 Rep Power: 17	First, convert the b.c.s of pressure values at diff crank angles in to perssure values at diff. time instant.VIZ. for 2400 rpm, u might be having pressure values at diff CAs, then knowing rpm, convert them to P at diff time instants....apply that as a profile in fluent and then select b.c.s.If u dont know how to write b.c.s follow the manuls from Fluent.

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November 15, 2009, 00:51		#3
uday Member uday Join Date: Sep 2009 Posts: 38 Rep Power: 17	Thanku for u r suggesion, i will try to do it.

November 16, 2009, 06:50		#4
uday Member uday Join Date: Sep 2009 Posts: 38 Rep Power: 17	I tried but iam not finding how to give these pressure values at different times(CA) with out writing udf.

November 17, 2009, 00:08		#5
uday Member uday Join Date: Sep 2009 Posts: 38 Rep Power: 17	Good morning friends, Iam simulating inlet manifold.For outlet of the manifold iam giving unsteady B.C using transient data file. Here two parameters are there one is time and another one is pressure. Now my question is how to divide this time parameter means in which(how much difference) steps i have to give. Please give me suggestion in this matter. Thanks in advance.