unit ?

faris · March 24, 2013, 12:04

Dear All,

I'm new in Flow-3D.
I work on physical models. In Weirs "free surface".
I have inquire: When we draw the shape in AutoCAD (eg x = 1 m). We open with MiniMagics shows "x = 1000 mm." When we insert the form in Flow-3D shows me the dimension "x = 1000". Knowing i work in the system (SI).
"x = 1000" in Flow-3D, Does this unit in millimeters or meters?
help me please.

Thank you,
Faris

dmilano · March 25, 2013, 10:03

FLOW-3D does not track units, so you just need to make sure that all inputs are in a consistent unit system (e.g. SI).

faris · March 25, 2013, 15:09

Thank you very much for your interest, I will try it.

faris · March 27, 2013, 05:13

Hi dmilano,

I have entered all the inputs in the system and a consistent unit.
The smaller dimension of the shape is (x = 0.002 m). When we do the mesh, The cell number up to more than 40 million. Is this normal ?

dmilano · March 27, 2013, 10:35

40M is large, but some problems require this many cells - it just depends on the size of the domain and the required cell size. Even so, it is worth double-checking your inputs to make sure that nothing was missed.

faris · March 31, 2013, 07:08

Hi dmilano,

I tried several attempts but did not succeed. Simulations stopped after taken a long time and i get an error message "Time-step size < dtmin".
Please if you have time, I send to you a prepin (input file) to investigate and show me the Mistake. Please help me.

saeedtk · June 25, 2013, 03:24

this error can have several reasons:
first of all check the manual there is part about troubleshooting.
the consider your mesh, first use a very coarse mesh if it again happen chand the order of solver or ur turbulence models.

good luck

March 24, 2013, 12:04	unit ?	#1
faris New Member faris abed Join Date: Mar 2013 Posts: 5 Rep Power: 13	Dear All, I'm new in Flow-3D. I work on physical models. In Weirs "free surface". I have inquire: When we draw the shape in AutoCAD (eg x = 1 m). We open with MiniMagics shows "x = 1000 mm." When we insert the form in Flow-3D shows me the dimension "x = 1000". Knowing i work in the system (SI). "x = 1000" in Flow-3D, Does this unit in millimeters or meters? help me please. Thank you, Faris

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March 25, 2013, 10:03		#2
dmilano Member Join Date: Mar 2012 Posts: 72 Rep Power: 14	FLOW-3D does not track units, so you just need to make sure that all inputs are in a consistent unit system (e.g. SI).

March 25, 2013, 15:09		#3
faris New Member faris abed Join Date: Mar 2013 Posts: 5 Rep Power: 13	Thank you very much for your interest, I will try it.

March 27, 2013, 05:13		#4
faris New Member faris abed Join Date: Mar 2013 Posts: 5 Rep Power: 13	Hi dmilano, I have entered all the inputs in the system and a consistent unit. The smaller dimension of the shape is (x = 0.002 m). When we do the mesh, The cell number up to more than 40 million. Is this normal ?

March 27, 2013, 10:35		#5
dmilano Member Join Date: Mar 2012 Posts: 72 Rep Power: 14	40M is large, but some problems require this many cells - it just depends on the size of the domain and the required cell size. Even so, it is worth double-checking your inputs to make sure that nothing was missed.

March 31, 2013, 07:08		#6
faris New Member faris abed Join Date: Mar 2013 Posts: 5 Rep Power: 13	Hi dmilano, I tried several attempts but did not succeed. Simulations stopped after taken a long time and i get an error message "Time-step size < dtmin". Please if you have time, I send to you a prepin (input file) to investigate and show me the Mistake. Please help me.

June 25, 2013, 03:24		#7
saeedtk New Member Join Date: May 2013 Posts: 6 Rep Power: 13	this error can have several reasons: first of all check the manual there is part about troubleshooting. the consider your mesh, first use a very coarse mesh if it again happen chand the order of solver or ur turbulence models. good luck