Modeling Moving Engine Parts Using the FLOW-3D GMO Model

Crankshaft in oil: CFD simulation
using fluid structure interaction

Fluid simulation of a moving piston
using fluid structure interaction

For many years, FLOW-3D’s automotive industry users have modelled the sloshing behaviour of oil, gasoline and other fluids in moving vehicles, using the codes non-inertial reference frame model. Recent releases of FLOW-3D have introduced a powerful new model which we refer to as the General Moving Object (GMO) model. This robust model allows users to simulate rigid body dynamics, with the object motion either fully coupled to the fluid flow or prescribed by the user. Fully-coupled solutions allow six-degrees-of-freedom or constraints such as fixed points/axes or prescribed forces or torques. This new model opens the potential for modelling moving engine parts, such as crankshafts, connecting rods and oil pumps and their effects on the sloshing behavior.

This new functionality can allow FLOW-3D users to determine complex problems such as how well cylinder walls are lubricated by the splashing of oil or how well oil is drawn through an oil pump. With this new GMO model, there are an enormous number of possibilities for fluid modelling that didn’t previously exist. Shown are some examples from simulations run with the new GMOmodel. First is an animation of a simplified crankshaft moving in a pool of oil.

With additional work, a customization available to users in maintenance, linked moving parts can be modelled, as with the representation of a moving piston.

Users interested in learning more can email us at Flow Science for more details.