time_advance Module

read time_advance_knobs namelist from the input file; sets the explicit time advance option, as well as allows for scaling of the x and y components of the magnetic drifts and of the drive term allocate distribution function sized arrays needed, e.g., for Runge-Kutta time advance set up neoclassical corrections to the equilibrium Maxwellian; only calculated/needed when simulating higher order terms in rhostar for intrinsic rotation calculate the term multiplying dg/dvpa in the mirror term and set up either the semi-Lagrange machinery or the tridiagonal matrix to be inverted if solving implicitly calculate the term multiplying dg/dz in the parallel streaming term and set up the tridiagonal matrix to be inverted if solving implicitly allocate and calculate the factors multiplying dg/dx, dg/dy, dphi/dx and dphi/dy in the magnetic drift terms allocate and calculate the factor multiplying dphi/dy in the gradient drive term

Arguments

allocate wdriftx_phi, the factor multiplying dphi/dx in the magnetic drift term allocate wdrifty_phi, the factor multiplying dphi/dy in the magnetic drift term allocate wdriftx_bpar, the factor multiplying dbpar/dx in the magnetic drift term allocate wdrifty_bpar, the factor multiplying dbpar/dy in the magnetic drift term allocate wdriftx_g, the factor multiplying dg/dx in the magnetic drift term allocate wdrifty_g, the factor multiplying dg/dy in the magnetic drift term this is the curvature drift piece of wdrifty with missing factor of vpa vpa factor is missing to avoid singularity when including non-Maxwellian corrections to equilibrium this is the grad-B drift piece of wdrifty if including neoclassical correction to equilibrium Maxwellian, then add in v_E^{nc} . grad y dg/dy coefficient here if maxwwellian_normalization = .true., evolved distribution function is normalised by a Maxwellian otherwise, it is not; a Maxwellian weighting factor must thus be included assign wdrifty_bpar, neoclassical terms not supported if including neoclassical corrections to equilibrium, add in -(Ze/m) * v_curv/vpa . grad y d/dy * dF^{nc}/dvpa term and v_E . grad z dF^{nc}/dz (here get the dphi/dy part of v_E) NB: the below neoclassical correction needs to be divided by an equilibrium Maxwellian if maxwellian_normalization = .true. this is the curvature drift piece of wdriftx with missing factor of vpa vpa factor is missing to avoid singularity when including non-Maxwellian corrections to equilibrium this is the grad-B drift piece of wdriftx if including neoclassical correction to equilibrium Maxwellian, then add in v_E^{nc} . grad x dg/dx coefficient here if maxwellian_normalizatiion = .true., evolved distribution function is normalised by a Maxwellian otherwise, it is not; a Maxwellian weighting factor must thus be included assign wdriftx_bpar, neoclassical terms not supported if including neoclassical corrections to equilibrium, add in (Ze/m) * v_curv/vpa . grad x d/dx * dF^{nc}/dvpa term and v_E . grad z dF^{nc}/dz (here get the dphi/dx part of v_E) and v_E . grad alpha dF^{nc}/dalpha (dphi/dx part of v_E) NB: the below neoclassical correction needs to be divided by an equilibrium Maxwellian if running with maxwellian_normalzation = .true.

Arguments

Arguments

Arguments

Arguments

Arguments

TODO:GA- add correct CFL condition

Arguments

Arguments

unless running in multibox mode, no need to worry about mb_communicate calls as the subroutine is immediately exited if not in multibox mode. save value of phi & apar for use in diagnostics (to obtain frequency) reverse the order of operations every time step as part of alternating direction operator splitting this is needed to ensure 2nd order accuracy in time

Arguments

advance_explicit takes as input the guiding centre distribution function in k-space and updates it to account for all of the terms in the GKE that are advanced explicitly in time

Arguments

advance_explicit_euler uses forward Euler to advance one time step

Arguments

advance_expliciit_rk2 uses strong stability-preserving RK2 to advance one time step

Arguments

strong stability-preserving RK3

Arguments

standard RK4

Arguments

solve_gke accepts as argument pdf, the guiding centre distribution function in k-space, and returns rhs_ky, the right-hand side of the gyrokinetic equation in k-space; i.e., if dg/dt = r, then rhs_ky = rdt; note that if include_apar = T, then the input pdf is actually gbar = g + (Ze/T)(vpa/c)F0

Arguments

Arguments

start timing the time advance due to the driving gradients

Arguments

advance_wdrifty_explicit subroutine calculates and adds the y-component of the magnetic drift term to the RHS of the GK equation

Arguments

advance_wdriftx_explicit subroutine calculates and adds the x-component of the magnetic drift term to the RHS of the GK equation

Arguments

compute phase factor needed when running with equilibrium flow shear compute ikyg FFT to get dg/dy in (y,x) space compute ikx zero out the zonal contribution to d/dx if requested if running with equilibrium flow shear, make adjustment to the term multiplying dg/dy FFT to get d/dx in (y,x) space multiply by the geometric factor appearing in the Poisson bracket; i.e., (dx/dpsidy/dalpha)0.5 compute the contribution to the Poisson bracket from dg/dy*d/dx

Arguments

check estimated cfl_dt to see if the time step size needs to be changed

Arguments

Arguments

compute dg/dy in k-space accepts g(ky,kx)

Arguments

compute dg/dy in k-space accepts g(ky,kx,z,tube)

Arguments

compute dg/dy in k-space accepts g(ky,kx,z,tube,(vpa,mu,spec))

Arguments

compute dg/dx in k-space accepts g(ky,kx)

Arguments

compute dg/dx in k-space accepts g(ky,kx,z,tube)

Arguments

compute dg/dx in k-space accepts g(ky,kx,z,tube,(vpa,mu,spec))

Arguments

Arguments

add vM . grad y d/dy or vM . grad x d/dx (or equivalents with g) or omega_* * d/dy term to RHS of GK equation

Arguments

Arguments

Arguments

Arguments

Arguments

Arguments

Arguments

Arguments

Arguments

Arguments