[rakeshpe]

HI,

I need to model a connecting rod as rigid body motion in a flow domain.

I modelled crankshaft as giving specific rotation. can i add as connected motion by restricting the smaller end of conrod only with liner motion.

Or individually through any specific equation

Thanks in advance

[Gert-Jan]

Please add a figure. A figure says more than thousand words...

[ghorrocks]

I worked in IC engine modelling for 10 years so know exactly what rakesh is talking about

The only way of doing this is the derive the equations of motion of the conrod and make them define the motion. CFX does not have a rigid body solver (in terms of rigid bodies interacting with other rigid bodies) so you cannot generate this motion from the crankshaft and piston motions.

Also - what approach are you using? Rigid bodies with dynamic remeshing? Or immersed solids?

[rakeshpe]

Originally Posted by ghorrocks

I worked in IC engine modelling for 10 years so know exactly what rakesh is talking about

The only way of doing this is the derive the equations of motion of the conrod and make them define the motion. CFX does not have a rigid body solver (in terms of rigid bodies interacting with other rigid bodies) so you cannot generate this motion from the crankshaft and piston motions.

Also - what approach are you using? Rigid bodies with dynamic remeshing? Or immersed solids?

i solved it guys. ghorrocks you were correct. i am using immersed body approach.

so added a rotary motion for crankshaft. added liner displacement for piston. general motion for conrod with the origin as piston pin moving with piston displacement and angular motion with respect to the piston pin.

thankyou guys for helping me out