[FLASH-USERS] Problem in solving jenas instability for spherical geometry using FLASH2.5

[John ZuHone]

Hello M.A.,

	With regards to your first question, are you using the jeans setup in  
the FLASH 2.5 source tree? There doesn't seem to be a setup called  
"testsph" in the setups directory. Also, it would be good to know  
whether you are using the multigrid or the multipole solver for  
gravity. Both the timestep being zero and the fact that the gravity  
solver complaining about Mtot = 0 suggest that something has gone  
wrong with the initial setup of density on the grid.

	I would have to think more carefully about your second question.

Best,

John ZuHone

	
On Jan 14, 2008, at 10:34 AM, M.A. Latife wrote:

> Hi
> Dear all,
> Hope you will be fine and enjoying good health.
> I have very basic questions.
> 1)i am trying to solve the jeans instability problem for spherical  
> geometryusing FLASH 2.5. when i run this problem for one dimensional  
> spherical geometry it gives the following error
> conditons for this problem are given below
> ./setup testsph -1d -auto result success
> make result success
> cd object
> ./flash2
>  WARNING: desired timestep < dtmin, using dtmin
>       24 1.4911E-01 1.0000E-08 |  0.000E+00
>
>  abort_flash called. See log file for details.
>  Calling MPI_Abort() for immediate shutdown!
>
> [0] MPI Abort by user Aborting program !
> [0] Aborting program!
> p0_18386:  p4_error: : 1
> in log file there is following error
> abort_message: FATAL:  find_center_of_mass:  Mtot = 0
> can  any body tell me why its is happening?
> 2) My second question is when i run it for two dimensional spherical  
> goemetry. For  this case when i choose  r=1.5 cm  there is more   
> density along the boundaries of circle (2-d spherical geometry. when  
> i choose r= 100 cm there is high density on centre in form of peak  
> but difference between maximum density and  minimum density  is  
> small(like max den=4.3*10^7 and min 9.9*10^6, while inital density  
> is 1.5*10^7, for cartesian coordinates max den=1.1*10^8,  min  
> 7.5*10^5, while inital density is 1.5*10^7). Intial conditions for  
> problem are given below.
> Can any one help me in this regard? I am not good user of FLASH,   
> trying to learn the FLASH.
> For two dimensional sperical geometry i am expcting centre collapse
>
> p0                             =  1.5E0
>  rho0                           =  1.5E7
>  lambdax                        =  5.0  kx=2pi/lambdax
>  lambday                        =  1.E10 ky=2pi/lambday
>  lambdaz                        =  1.E10 kz=2pi/lambdaz
>  amplitude                      =  0.001
>   Computational domain
>
>  xmin                           = 0.0
>  xmax                           = 1.0E2
>  ymin                           =-1.0
>  ymax                           = 1.0
>  zmin                           =  0.
>  zmax                           = 0.
>
>  geometry                       = "spherical"
>
>  xl_boundary_type               = "reflect"
>  xr_boundary_type               = "periodic"
>  yl_boundary_type               = "periodic"
>  yr_boundary_type               = "periodic"
>  zl_boundary_type               =  "periodic"
>  zr_boundary_type               =  "periodic"
> nblockx                        =  2
>  nblocky                        =  2
> dtini                          =  1.0E-5
>  dtmin                          =  1.0E-8
>  dtmax                          =  1.0E-2
>  Gravity
>
>  igrav                          =  1
>  grav_boundary_type             = "isolated"
>     mpole_lmax               = 0.0
> rho=rho0(1+amplitude(cos(krcos(theta)+krsin(theta)))
> p=p0(1+gamma*amplitude(cos(krcos(theta)+krsin(theta)))
> kj=sqrt(4*pi*G*rho0)/c0
> c0=sqrt(gamma*p0/rho0)
>
> I will be very thankful to you for ur kind help in this regard
> thanks in advance
> cheers
> M.A.Latife
>
>
>