Learning Forum

[CptCamembert]

Hello,

 

I want to simulate how manifold injection of a gaseous fuel into an internal combustion engine compares to direct injection of the same fuel using the ICE Coldflow module. I already got the manifold injection cycle running, but the direct injection one is giving me some trouble.

This module offers the possibility to tick a spray cone option in the Design Modellers Input Manager, however, this doesn't work. I tried creating geometry representing the injector nozzle with six pinhole faces representing the holes of the injector and use transient boundary conditions using a profile file. This also didn't work, because it either diverged immediately or just didn't apply the profile correctly. Also backflow prevention is disabled for multiphase flow, so using a pressure/velocity or mass-flow inlet won't work because of this. I now want to use dynamic mesh events to change the boundary conditions of those faces during the simulation. In the events panel, there is a way to change zone type, but it doesn't let you change a zone into an input or output.

What would the commands look like if I wanted to start injection at crank angle X and stop injection and crank angle Y with a constant pressure of P?

I also have a general question about multiphase flow, more specifically defining a gaseous phase. If I change the density to ideal gas, (which I would have to do to be able to simulate compressible flow, right?), where can I then define the density at reference temperature and pressure? As I understand, If I leave the pressure constant, I'm essentially simulating incompressible flow. Also what Model would be the best to use for simulating multphase analysis of two gaseous phases?

 

Thank you.