Learning Forum

[Rajat25Arya]

I am facing some problem in simulating the Cold Flow Analysis of IC Engine. I have to do full cycle simulation 0-720 CA but when piston reaches 155 degree CA Exhaust Valve opens and solver shows an error "Update Dynamic mesh Failed, Negative cell volume detected".
this error also occurs when inlet valve opens at 318 degree CA.
Except this the simulation is running quite good.
 My solver is ANSYS FLUENT IC Engine 16.2.

Input Parameters are
connecting rod = 130 mm
crank radius= 44 mm
Engine speed=2000 RPM
minimum valve lift= 0.1 mm

This problem is solved by using "Keygrids" on that specific angle but then another error occurs named "UNASSIGNED INTERFACE DETECTED" simulation stops.

[seeta gunti]

Hello Rajat,

The error "Unassigned interface detected" means that you have some non-cormal interface zones which needs to stitched together. When you have non conformal interfaces, like interface 1 and interface 2 defined after reading the mesh into fluent, you need to visit mesh interfaces and select these two in each colume and give a new name of the interface and hit create. This will take care of transferring fluxes across two zones and interfaces.

For more information, you can go through the Fluent help manual.

Thanks,

Seeta