arnica.phys package

Physical utilities

The phys package provides physical utilities for computational fluid dynamics (CFD) problems. It includes modules for thermodynamic properties, solid materials, and wall thermal equilibrium.

  • thermodyn_properties: computes thermal constants and values related to turbulence.

  • solid_material: represents a solid material with methods for calculating thermal conductivity and resistance.

  • yk_from_phi: calculates mass fractions of species from a given Phi coefficient.

  • wall_thermal_equilibrium: computes the thermal equilibrium for a 2-layer wall (Metal/ceramic) by iteratively estimating temperatures until convergence.

Submodules

arnica.phys.solid_material module

This module defines a class SolidMaterial that represents a solid material for thermal computations.

This class has two main methods: lambda_th and thermal_resistance : The lambda_th method returns the thermal conductivity (lambda) of the material at a given temperature. It clips the input temperature to ensure it falls within the valid range defined by _lambda_range. The method then uses the polynomial representation of the material’s thermal conductivity to calculate the value at the clipped temperature.

The thermal_resistance method calculates the thermal resistance of a layer with a given width and estimated temperature (t_est). It returns the thermal resistance in units of square meters per Kelvin per Watt (m2.K/W).

class arnica.phys.solid_material.SolidMaterial(lambda_poly, lambda_range)

Bases: object

define properties of a solid material object

lambda_th(temperature)

return the lambda of ceramics material [W/mK]

thermal_resistance(width, t_est)

return the thermal resistance [m2.K/W] width : width of the layer t_est : estimated temperature of the layer

arnica.phys.thermodyn_properties module

This module provides functions for computing thermodynamic properties, specifically thermal constants and values related to turbulence. The thermal_constants function generates a dictionary containing various thermal constants used in calculations. The _estimate_log_region function evaluates the value of u_tau in the log region using a recursive loop. The _estimate_t_tau function computes the value of T_tau.

arnica.phys.thermodyn_properties.fluid_cp(temp, clipping=False)

compute cp of fluid

Args:

temp (TYPE): Description clipping (bool, optional): Description

Returns:

TYPE: Description

arnica.phys.thermodyn_properties.h_kader(t_wall, rho_wall, y_wall, u_2, t_2, temp_adiab)

compute h at the wall as in kader names taken equalt to loglaw_cwm.f90 AVBP

Args:

t_wall (TYPE): Description rho_wall (TYPE): Description y_wall (TYPE): Description u_2 (TYPE): Description t_2 (TYPE): Description temp_adiab (TYPE): Description

Returns:

TYPE: Description

arnica.phys.thermodyn_properties.lambda_cp_visco_fluid(temperature)

compute Fluid properties lambda , cp, visco

Args:

temperature (TYPE): Description

Returns:

TYPE: Description

arnica.phys.thermodyn_properties.thermal_constants()

Generate a dictionnary of thermal constants

Returns:

TYPE: Description

arnica.phys.thermodyn_properties.viscosity_sutherland(temp)

compute visocity as in sutherland

Args:

temp (TYPE): Description

Returns:

TYPE: Description

arnica.phys.wall_thermal_equilibrium module

module to compute wall equilibrium

arnica.phys.wall_thermal_equilibrium.compute_equilibrium(hot_t_ad, cold_t_ad, hot_h, cold_h, metal, ceram, ep_metal, ep_ceram)

compute the wall equilibrium

    - - - - - - - >
    HOT SIDE  hot_h, hot_t_ad

 ^ phi
_|___________________  t_ceram_hot
 |       Layer 2
_|___________________ t_eq
 |       Layer 1
_|___________________ t_metal_hot
 |
    COLD SIDE cold_h, cold_t_ad
    - - - - >

arnica.phys.yk_from_phi module

This script calculate mass_fraction of species from a Phi

arnica.phys.yk_from_phi.phi_from_far(far, c_x, h_y)

Return phi coefficient with the fuel air ratior coeff + fuel composition.

Parameters:

  • far (float) – the air-fuel ratio:

  • c_x (float) – stoechio coeff of Carbone

  • h_y (float) – stoechio coeff of hydrogene

arnica.phys.yk_from_phi.yk_from_phi(phi, c_x, h_y)

Return the mass fraction of elements from a fuel aspect ratio and stoechio element coeff.

Parameters:

  • phi (float) – the air-fuel aspect ratio

  • c_x (float) – stoechio coeff of Carbone

  • h_y (float) – stoechio coeff of hydrogene