Temperature dependent on air properties

Reto · September 9, 2010, 12:25

Hello,

I am working on natural convection on a vertical heated plate. I set the plate temperature high (~700 K), so it seems that the flow over the plate is turbulent flow. These are my questions:

1. Most of properties for Air 25 C have constant value. Is there the built-in properties of the air depending on temperature?

2. What value of y+ should I use in meshing procedure for simulating the viscous sublayer?

Please give me suggestions. Thank you in advance!

ghorrocks · September 9, 2010, 19:52

1) No. You will have to define it yourself.
2) You need to do a sensitivity study to establish this. Are you sure you need to model the sublayer? You might be turbulent enough that wall functions are OK and then meshing is much easier.

September 9, 2010, 12:25	Temperature dependent on air properties	#1
Reto New Member WIROTE Join Date: Jul 2010 Posts: 2 Rep Power: 0	Hello, I am working on natural convection on a vertical heated plate. I set the plate temperature high (~700 K), so it seems that the flow over the plate is turbulent flow. These are my questions: 1. Most of properties for Air 25 C have constant value. Is there the built-in properties of the air depending on temperature? 2. What value of y+ should I use in meshing procedure for simulating the viscous sublayer? Please give me suggestions. Thank you in advance!

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September 9, 2010, 19:52		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,854 Rep Power: 144	1) No. You will have to define it yourself. 2) You need to do a sensitivity study to establish this. Are you sure you need to model the sublayer? You might be turbulent enough that wall functions are OK and then meshing is much easier.