Description
Calculate the virtual temperature Tv(K) from temperature T(C), pressure P(mb) and relative humidity rh(%).
Pws(t,p) is the saturation vapor pressure with respect to water.
This virtual temperature equation was used in Aspen through V3.4.4, when it was replaced by a newer equation.
Formula
$$
w = P_{ws}(t+273.15, P) * 0.01 rh \\
T_v = (T + 273.15)(1.0 + 0.609w)
$$
Source
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