Learning Forum

[gianc]

I was doing a simulation of an ICE when it failed and it appeared this error.

Recycling requested by velocity iterations
Recycling requested by velocity iterations
Recycling requested by velocity iterations
Recycling requested by velocity iterations

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Error: Run aborting because the timestep is being driven too small.
The cause of this is: "Halved (recycling)"
    dt = 2.98083E-14 [s]
     t = 0.00000E+00 [s]
   cycle =      0
   crank =   331.00 [deg]
Error: Check the consistency of your initial or boundary conditions.

I noticed "Recycling requested by velocity iterations" begins after the exhaust valve starts to open and at that instant MaxV[m/s] is equal to -1.00E+08 .
Do anyone knows how to solve it?
Thanks in advance.

[RK]

Hello, 

Here are some suggestions : 

1. The piston should be at the TDC position in the surface mesh. Make sure this is correct in your setup.
2. For slider crank mesh motion the direction vector should point from BDC to TDC.
3. For time step size settings you should always try the default values first. Do not try to use too large values because this can cause the piston to sweep through more than one cell in one time step and consequently causes errors.