[FLASH-USERS] Error in AMR Prolong Routine

[Anshu Dubey]

James,

There is no place where density gets set to 0 explicitly. Normally we
encounter density going 0 only when the memory is getting trampled
somewhere, and so there is some bug somewhere. If you are seeing this
in the recv array, then you might be skirting too close to using up
all the available memory on the system. One such situation we
encounterd once  had to do with there being not enough memory for an
allocate call, but instead of reporting error, the system returned the
call and memory trampled.

Anshu

On Thu, Apr 9, 2009 at 12:04 AM, James Guillochon <jfg at ucolick.org> wrote:
> Hi guys,
> I am running a simulation in FLASH 3.0 using multiple species, and after
> about 5000 time steps, I run into the following error:
> [amr_prolong_gen_unk1_fun] PE=      7, ivar= 13, value= 24.0
>
> Trying to convert non-zero mass-specific variable to per-volume form in
> monotonic mesh interpolation, but dens is zero!
> The ivar = 13 being referred to here is the first species in my species list
> defined in Flash.h, which at the time of the abort is equal to smallx
> everywhere. It appears from the code that the recv variable array must have
> a zero value for density in at least one grid cell, but as far as I'm aware
> the density variable should never drop below smallrho!
> Tracking the origin of this issue could take a very long time, so I was
> hoping someone here has encountered this issue before and knows of a remedy?
> Is there anywhere in FLASH where the density is set explicitly to zero?
> Thanks!
> --
> James Guillochon
> Department of Astronomy & Astrophysics
> University of California, Santa Cruz
> jfg at ucolick.org
>