constitutive or closure relations

eric weddle · January 25, 2012, 05:51

What exactly are constitutive or closure relations ?

I've read this term all over an CFD article I read, and I don't know the exact meaning of it.

Would you mind helping me?

cfdnewbie · January 25, 2012, 14:11

hey eric,
would is meant by that term is usually the "closure" for any unknowns in your solution. Let's say for the Navier-Stokes equations, you have 5 equations: momentum in 3 directions, mass and energy conservations. Your equations however contain 6 unknown (u,v,q,p,rho,T), so you need a sixth equation to close the system: the equation of state relating rho, p and T!

January 25, 2012, 05:51	constitutive or closure relations	#1
eric weddle New Member Join Date: Sep 2011 Posts: 12 Rep Power: 15	What exactly are constitutive or closure relations ? I've read this term all over an CFD article I read, and I don't know the exact meaning of it. Would you mind helping me?

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January 25, 2012, 14:11		#2
cfdnewbie Senior Member cfdnewbie Join Date: Mar 2010 Posts: 557 Rep Power: 20	hey eric, would is meant by that term is usually the "closure" for any unknowns in your solution. Let's say for the Navier-Stokes equations, you have 5 equations: momentum in 3 directions, mass and energy conservations. Your equations however contain 6 unknown (u,v,q,p,rho,T), so you need a sixth equation to close the system: the equation of state relating rho, p and T!