Files
MeanField/tests/physics/barotrope.cpp
Emily Boudreaux 36adfa1174 feat(FieldDofMap): Completed FieldDofMap migration
also removed legacy BarotropicPolytrope implementation
2026-08-29 08:56:36 -04:00

123 lines
4.0 KiB
C++

#include <array>
#include <cmath>
#include <limits>
#include <catch2/catch_test_macros.hpp>
#include <catch2/matchers/catch_matchers_floating_point.hpp>
import mean_field;
import test_helpers;
TEST_CASE("Polytropic EOS Satisfies Its Analytic Identities",
tags::barotrope_eos_unit) {
constexpr double polytropic_index = 3.0;
constexpr double polytropic_constant = 1.5;
const mean_field::eos::Polytrope barotrope(polytropic_index,
polytropic_constant);
const std::array<double, 5> densities{1.0e-6, 1.0e-3, 0.1, 0.7, 2.0};
for (const double density : densities) {
const double pressure = barotrope.pressure_from_density(density);
const double enthalpy = barotrope.enthalpy_from_density(density);
const double reconstructed_density =
barotrope.density_from_enthalpy(enthalpy);
const double reconstructed_pressure =
barotrope.pressure_from_enthalpy(enthalpy);
const double reconstructed_enthalpy =
barotrope.enthalpy_from_pressure(pressure);
CHECK_THAT(reconstructed_density,
Catch::Matchers::WithinRel(density, 2.0e-14));
CHECK_THAT(reconstructed_pressure,
Catch::Matchers::WithinRel(pressure, 2.0e-14));
CHECK_THAT(reconstructed_enthalpy,
Catch::Matchers::WithinRel(enthalpy, 2.0e-14));
CHECK_THAT(pressure,
Catch::Matchers::WithinRel(
density * enthalpy / (polytropic_index + 1.0), 2.0e-14));
CHECK_THAT(barotrope.pressure_derivative_from_enthalpy(enthalpy),
Catch::Matchers::WithinRel(density, 2.0e-14));
CHECK_THAT(
barotrope.pressure_derivative_from_density(density),
Catch::Matchers::WithinRel(enthalpy / polytropic_index, 2.0e-14));
}
}
TEST_CASE("Polytropic EOS Derivatives Match Centered Differences",
tags::barotrope_eos_jacobian) {
const mean_field::eos::Polytrope barotrope(3.0, 1.5);
const std::array<double, 4> enthalpies{0.05, 0.2, 0.7, 1.4};
for (const double enthalpy : enthalpies) {
const double step = 1.0e-6 * std::max(1.0, enthalpy);
const double density_difference =
(barotrope.density_from_enthalpy(enthalpy + step) -
barotrope.density_from_enthalpy(enthalpy - step)) /
(2.0 * step);
const double pressure_difference =
(barotrope.pressure_from_enthalpy(enthalpy + step) -
barotrope.pressure_from_enthalpy(enthalpy - step)) /
(2.0 * step);
CHECK_THAT(
density_difference,
Catch::Matchers::WithinRel(
barotrope.density_derivative_from_enthalpy(enthalpy), 5.0e-10));
CHECK_THAT(
pressure_difference,
Catch::Matchers::WithinRel(
barotrope.pressure_derivative_from_enthalpy(enthalpy), 5.0e-10));
}
}
TEST_CASE("Polytropic EOS Has An Exact Zero Density Surface",
tags::barotrope_eos_unit) {
const mean_field::eos::Polytrope barotrope(3.0, 1.5);
CHECK(barotrope.density_from_enthalpy(-1.0) == 0.0);
CHECK(barotrope.density_from_enthalpy(0.0) == 0.0);
CHECK(barotrope.pressure_from_enthalpy(-1.0) == 0.0);
CHECK(barotrope.pressure_from_enthalpy(0.0) == 0.0);
CHECK(barotrope.density_derivative_from_enthalpy(-1.0) == 0.0);
CHECK(barotrope.density_derivative_from_enthalpy(0.0) == 0.0);
CHECK(barotrope.pressure_derivative_from_enthalpy(0.0) == 0.0);
}
TEST_CASE("Polytropic EOS Rejects Invalid Material Parameters",
tags::barotrope_eos_unit) {
CHECK_THROWS_AS(mean_field::eos::Polytrope(0.5, 1.0), std::invalid_argument);
CHECK_THROWS_AS(mean_field::eos::Polytrope(3.0, 0.0), std::invalid_argument);
CHECK_THROWS_AS(
mean_field::eos::Polytrope(std::numeric_limits<double>::infinity(), 1.0),
std::invalid_argument);
const mean_field::eos::Polytrope barotrope(3.0, 1.0);
CHECK_THROWS_AS(barotrope.pressure_from_density(-1.0), std::domain_error);
CHECK_THROWS_AS(barotrope.enthalpy_from_density(-1.0), std::domain_error);
CHECK_THROWS_AS(barotrope.enthalpy_from_pressure(-1.0), std::domain_error);
}