how to model varying gravity in Star CCM+

mohan makana · November 15, 2009, 10:07

I am trying to model some sloshing analysis in a fuel tank of an marine engine. I want to give accel/decel which is varying with time.
In reference values i was able to give constant accel/decel but not varying. I will be thankful if some one can provide me solution.

ping · November 25, 2009, 01:06

Two suggestions:

1. very easy method - simply type an equation into the gravity setting for X (ie replace 0 with say sin($Time * 3.2) or whatever.

2. easy method - create a field function called say GravX, and set its value to the required equation -
eg sin($Time * 3.2). Then simply type this field function name into the gravity setting for X (ie replace 0 with $GravX).

Even thought lots of menus dont have a field function dropdown and only constant settings, you can still type in a field function name or equation - very handy and not well documented!

3. harder method - do a java macro and solve via the macro changing the gravity constants every timestep.

November 15, 2009, 10:07	modeling of slosh analysis with time varying accel/decell	#1
mohan makana New Member joy Join Date: Nov 2009 Posts: 1 Rep Power: 0	I am trying to model some sloshing analysis in a fuel tank of an marine engine. I want to give accel/decel which is varying with time. In reference values i was able to give constant accel/decel but not varying. I will be thankful if some one can provide me solution. Last edited by mohan makana; November 15, 2009 at 10:27. Reason: delete

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November 25, 2009, 01:06		#2
ping Senior Member Ping Join Date: Mar 2009 Posts: 556 Rep Power: 20	Two suggestions: 1. very easy method - simply type an equation into the gravity setting for X (ie replace 0 with say sin($Time * 3.2) or whatever. 2. easy method - create a field function called say GravX, and set its value to the required equation - eg sin($Time * 3.2). Then simply type this field function name into the gravity setting for X (ie replace 0 with $GravX). Even thought lots of menus dont have a field function dropdown and only constant settings, you can still type in a field function name or equation - very handy and not well documented! 3. harder method - do a java macro and solve via the macro changing the gravity constants every timestep.