Theory

The ambient temperature enters the heat-loss condition as $T_a$ (Ta), in the convective and radiative fluxes and in the film temperature of the outer correlations (Outer environment). The Material step sets the gas temperature and the ambient pressure but no ambient temperature, so auto uses a fixed 20 °C. Enter a value for a hot engine bay or a cold climate.

Equations

T_a = 20 + 273.15\ \text{K (auto)}, \qquad T_f = \frac{T_s + T_a}{2}

(1)

where	meaning	unit
$T_a$	Ambient temperature	K
$T_s$	Outer surface temperature	K
$T_f$	Film temperature of the outer air properties	K

Default and rule

Default: auto: 20 °CComputed by the program
Rule: Auto: 20 °C.
Source: The auto value of 20 °C is the program's default; it is not derived from a published source. The radiated-noise panel has its own ambient temperature, independent of this one.

Valid range above −273.15 °C

Units

Degrees Celsius.

One value

The same temperature applies to convection and radiation; surroundings hotter than the air (an engine, exhaust parts) are not modelled.

Theory

Equations

Default and rule

Valid range above −273.15 °C

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