PLUTO Test Problems
4.4-patch2
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Single CR particle gyration (and drift) test. More...
Functions | |
void | InitDomain (Data *d, Grid *grid) |
void | Analysis (const Data *d, Grid *grid) |
void | BackgroundField (double x1, double x2, double x3, double *B0) |
Test particle gyration in EM fields.
The time steps for partciles and fluid scale as
dt_pa = Na*dx/vp (if limited by translation) dt_pg = 1/(Ng*Omega) (if limited by gyration) dt_f = Ca*dx/lambda
where lambda = B/sqrt(rho) (when p << 1), Omega = q*B/(m*c), Ng and Na are some integers, Ca is the Courant number.
We set B = H*dx so the fluid time step is approximately the same at any resolution:
dt_pa = Na*dx/vp dt_pg = 1/(Ng*H*dx*q/mc) dt_f = Ca*sqrt(rho)/H
The ratio between particle and fluid time steps is:
dt_pa / dt_f = Na*dx*H/(vp*Ca*sqrt(rho)) dt_pg / dt_f = mc/(Ng*q*Ca*sqrt(rho)*dx)
References:
void Analysis | ( | const Data * | d, |
Grid * | grid | ||
) |
void BackgroundField | ( | double | x1, |
double | x2, | ||
double | x3, | ||
double * | B0 | ||
) |
Define the component of a static, curl-free background magnetic field.
[in] | x1 | position in the 1st coordinate direction ![]() |
[in] | x2 | position in the 2nd coordinate direction ![]() |
[in] | x3 | position in the 3rd coordinate direction ![]() |
[out] | B0 | array containing the vector componens of the background magnetic field |