Definitions
Conductivity—W/(m-K) is a thermal transport property of the fluid or solid, relating the heat flux (W/m2) to the temperature gradient according to Fourier's Law
q=– k▽T
Conjugate Wall—Interface between materials with different thermal properties, such as solid-liquid interfaces and solid-solid interfaces between different solid materials.
Internal Energy (u)—Thermodynamic specific internal energy (J/kg) of the fluid or solid.
Enthalpy (h)—Measure of the energy (J/kg) of a thermodynamic system as defined below:
Enthalpy
where,
h
enthalpy
u
internal energy
P
v
specific volume
Temperature—Absolute temperature Kelvin (K) in flow analysis or the driving potential for energy transfer as heat in thermodynamic properties.
Energy Avg T—Average temperature determined by integrating and averaging the energy and then converting to temperature. The energy avg T calculation assumes that the specific heat is constant.
Flux per Area—Average wattage per area (W/m2) of heat crossing a selected boundary or interface.
Heat Capacity—(J/(kg-K)) thermal property of the fluid or solid, relating the rate of change of enthalpy with respect to temperature.
Heat Capacity
Constant Capacity—Option for computing the relationship between temperature (T) and interfaces (h) based on a constant specific heat.
Heat Capacity
Mass Avg. Enthalpy—Average enthalpy in a selected volume based on a mass average, not volume average.
Total Enthalpy or Stagnation Enthalpy—Related to static enthalpy h as follows:
Total Enthalpy
where,
htotal
total enthalpy (J/kg)
h
static enthalpy (J/kg)
V
velocity (m/s)
Mass Avg. Tot. Enthalpy—Average total enthalpy in a selected volume based on a mass average, not volume average.
Mass Avg. Internal Energy—Average internal energy in a selected volume based on a mass average, not volume average.
Tot. Internal Energy (utotal—Internal energy at stagnation (J/kg) of the fluid or solid.
Total Internal Energy
where,
utotal
total internal energy (J/kg)
u
internal energy (J/kg)
V
velocity (m/s)
Mass Avg. Tot. Internal Energy—Average total internal energy in a selected volume based on a mass average (as opposed to a volume average).
Prandtl Number—Ratio of momentum diffusivity (kinematic viscosity) to thermal diffusivity.
Total Flux—Total wattage (W) of heat crossing a selected boundary or interface.
Total Temperature or Stagnation Temperature—Related to the static temperature (T) as follows:
Total Temperature
Ttotal
total temperature (K)
T
static temperature (K)
Cp
specific heat
V
velocity (m/s)