Diagnostics

diagnostics

This module provides a class to simplify computing of diagnostics typically encountered in geodynamical simulations. Users instantiate the class by providing relevant parameters and call individual class methods to compute associated diagnostics.

GeodynamicalDiagnostics(z, T, bottom_id, top_id, quad_degree=4)

Typical simulation diagnostics used in geodynamical simulations.

Parameters:

Name	Type	Description	Default
z	Function	Firedrake function for mixed Stokes function space (velocity, pressure)	required
T	Function	Firedrake function for temperature	required
bottom_id	int	Bottom boundary identifier	required
top_id	int	Top boundary identifier	required
quad_degree	int	Degree of polynomial quadrature approximation	4

Note

All diagnostics are returned as floats.

Methods:

Name	Description
u_rms	Root-mean squared velocity
u_rms_top	Root-mean squared velocity along the top boundary
Nu_top	Nusselt number at the top boundary
Nu_bottom	Nusselt number at the bottom boundary
T_avg	Average temperature in the domain
T_min	Minimum temperature in domain
T_max	Maximum temperature in domain
ux_max	Maximum velocity (optionally over a given boundary)

Source code in g-adopt/gadopt/diagnostics.py

def __init__(
    self,
    z: Function,
    T: Function,
    bottom_id: int,
    top_id: int,
    quad_degree: int = 4,
):
    mesh = extract_unique_domain(z)

    self.u, self.p, *_ = z.subfunctions
    self.T = T

    self.dx = dx(domain=mesh, degree=quad_degree)
    self.ds = (
        CombinedSurfaceMeasure(mesh, quad_degree)
        if T.function_space().extruded
        else ds(mesh)
    )
    self.ds_t = self.ds(top_id)
    self.ds_b = self.ds(bottom_id)

    self.n = FacetNormal(mesh)

    self.domain_volume = assemble(Constant(1) * self.dx)
    self.top_surface = assemble(Constant(1) * self.ds_t)
    self.bottom_surface = assemble(Constant(1) * self.ds_b)