Hi Zach, As Freddie suggests, it may be because you are spatially under resolved.
Could you post the revised mesh? What it the Reynolds number? What is the Mach number? Cheers Peter Dr Peter Vincent MSci ARCS DIC PhD Senior Lecturer and EPSRC Early Career Fellow Department of Aeronautics Imperial College London South Kensington London SW7 2AZ UK web: www.imperial.ac.uk/aeronautics/research/vincentlab twitter: @Vincent_Lab On 18 Nov 2014, at 07:24, Freddie Witherden <[email protected]> wrote: > Hi Zach, > > On 17/11/2014 20:00, Zach Davis wrote: >> As you noted I included a pole in my mesh. I’ve gone another route >> with the meshing, and that seems to have resolved my initial issue. >> However, now during the course of simulation I get a runtime error >> indicating the “Minimum sized time step rejected”. I’m looking for >> some clarification here—does this indicate my min-fact is too small, >> or too large? Or does it have to do with the actual tolerance values >> that I've set? Thanks! > > The adaptive RK schemes control the error by increasing/reducing the > time step as necessary. If the error incurred through a step is too > high (or NaN!) the time step will be reduced by a factor of up to > min-fact. Sometimes, however, the problem is not with the temporal > resolution of the system but with the spatial resolution. Should this > be the case then reducing the time step will have little to no effect. > > As a consequence the adaptive schemes will keep reducing the time step > until they reach the minimum time step permitted by PyFR (dt-min which > defaults to ~1e-14). If a dt-min time step is rejected then we raise. > > It is therefore likely that the issue is due to a lack of spatial > resolution/anti-aliasing/filtering. > > Regards, Freddie. > > -- > You received this message because you are subscribed to the Google Groups > "PyFR Mailing List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send an email to [email protected]. > Visit this group at http://groups.google.com/group/pyfrmailinglist. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "PyFR Mailing List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. Visit this group at http://groups.google.com/group/pyfrmailinglist. For more options, visit https://groups.google.com/d/optout.
