This page is an introduction/reminder on the types of post-processing available in TrioCFD/TRUST and the various variables accessible for visualizing TrioCFD multiphase calculations.

Types of post-processing

Depending on the case under study and the variables of interest, TRUST offers a range of post-processing options:

individual points of interest (Point keyword),
distributed points along a linear path (Segment keyword),
points arranged according to a predefined layout (Plan keyword),
points arranged within a parallelepiped structure (Volume keyword),
fields across the entire domain (Fields keyword — requires the field's location on the mesh (faces, elements or vertices), name, post-processing time and a backup file),
statistical measurements applied to fields to compute the mean value, standard deviation or correlation between two fields (Statistics keyword — requires a time window, time step and the desired statistical methods).

Variables easily accessible

To ease post-processing, some variables are already accessible with keywords, summarised below.

Mesh-related keywords

Name	Notation	Keyword	Unit
Cell volumes	\(V_{cell}\)	Volume_maille	\(m^3\)
Stability time steps	\(\Delta t\)	Pas_de_temps	\(s\)
Volumetric porosity	\(\epsilon\)	Porosite_volumique
Distance to the wall	\(y_w\)	Distance_Paroi	\(m\)
Cell Courant number (VDF only)	\(C_o=\frac{u\Delta t}{\Delta x}\)	Courant_maille
Cell Reynolds number (VDF only)	\(Re=\frac{u\Delta x}{\nu}\)	Reynolds_maille

Mass keywords

Name	Notation	Keyword	Unit
Density	\(\rho\)	masse_volumique	\(kg.m^{-3}\)
Void fraction	\(\alpha\)	Alpha	dimensionless
Mass balance on each cell	\(\nabla \cdot u\)	Divergence_U	\(m^3.s^{-1}\)

Momentum equation keywords

Name	Notation	Keyword	Unit
Velocity	\(u\)	Vitesse / Velocity	\(m.s^{-1}\)
Velocity residual	\(u_{res}\)	Vitesse_residu	\(m.s^{-2}\)
Kinetic energy per element	\(\frac{1}{2}\rho u^2\)	Energie_cinetique_elem	\(kg.m^{-1}.s^{-2}\)
Total kinetic energy	\(\frac{1}{2}\rho u^2\)	Energie_cinetique_totale	\(kg.m^{-1}.s^{-2}\)
Vorticity	\(w=\mathrm{rot}\,u\)	Vorticite	\(s^{-1}\)
Pressure (incompressible)	\(\frac{P}{\rho}+gz\)	Pression	\(Pa.m^3.kg^{-1}\)
Pressure (incompressible)	\(P+\rho gz\)	Pression_pa / Pressure	\(Pa\)
Pressure (compressible)	\(P\)	Pression	\(Pa\)
Hydrostatic pressure	\(\rho gz\)	Pression_hydrostatique	\(Pa\)
Total pressure	\(P_{tot}\)	Pression_tot	\(Pa\)
Pressure gradient	\(\nabla(\frac{P}{\rho}+gz)\)	Gradient_pression	\(m.s^{-2}\)
Velocity gradient	\(\nabla u\)	gradient_vitesse	\(s^{-1}\)
Local shear strain rate	\(\sqrt{2S_{ij}S_{ij}}\)	Taux_cisaillement	\(s^{-1}\)
Viscous / pressure / total force		Viscous_force, Pressure_force, Total_force (and _x/_y/_z)	\(kg.m^2.s^{-1}\)
Component velocity	\(u_X\), \(u_Y\), \(u_Z\)	VitesseX, VitesseY, VitesseZ	\(m.s^{-1}\)
Source term in non-Galilean reference frame	\(a\)	Acceleration_terme_source	\(m.s^{-2}\)

Energy equation keywords

Name	Notation	Keyword	Unit
Temperature	\(T\)	Temperature	\(K\)
Temperature residual	\(T_{res}\)	Temperature_residu	\(K.s^{-1}\)
Temperature variance	\(Var(T)\)	Variance_Temperature	\(K^{2}\)
Temperature dissipation rate		Taux_Dissipation_Temperature	\(K^2.s^{-1}\)
Temperature gradient	\(\nabla T\)	Gradient_temperature	\(K.m^{-1}\)
Heat exchange coefficient	\(h\)	H_echange_Tref	\(W.m^{-2}.K^{-1}\)
Internal energy	\(U\)	energie_interne	\(J\)
Enthalpy	\(H\)	enthalpie	\(J\)
Irradiancy	\(I\)	Irradiance	\(W.m^{-2}\)
Volumic thermal power	\(P_w\)	Puissance_volumique	\(W.m^{-3}\)

Turbulence equations keywords

Name	Notation	Keyword	Unit
Turbulent viscosity	\(\nu_t\)	Viscosite_turbulente	\(m^2.s^{-1}\)
Turbulent dynamic viscosity	\(\mu_t\)	Viscosite_dynamique_turbulente	\(kg.m.s^{-1}\)
Turbulent kinetic energy	\(\rho k\)	Energy	\(kg.m^2.s^{-2}\)
Turbulent dissipation rate	\(\varepsilon\)	Eps	\(m^2.s^{-3}\)
Specific dissipation rate	\(\omega\)	omega	\(s^{-1}\)
Specific dissipation time scale	\(\tau\)	tau	\(s\)
Q-criterion	\(Q\)	Critere_Q	\(s^{-1}\)
Distance to the wall	\(y^+\)	Y_plus
Friction velocity	\(u^*\)	U_star	\(m.s^{-1}\)
Turbulent heat flux		Flux_Chaleur_Turbulente	\(m.K.s^{-1}\)

Two-phase models keywords

Name	Notation	Keyword	Unit
Drag force	\(F_D\)	Drag	\(N.m^{-3}\)
Lift force	\(F_L\)	Lift	\(N.m^{-3}\)
Dispersion force	\(F_{Disp}\)	Disp	\(N.m^{-3}\)
Lubrication force	\(F_{Lub}\)	Lub	\(N.m^{-3}\)
Bubble diameter	\(d_b\)	d_bulles	\(m\)

Physical properties (conductivity, diffusivity, etc.) can also be post-processed. Furthermore, the Definitionchamps keyword can be used to create new or more complex fields for advanced post-processing.