Correction for Upstream Temperature

Isentropic Exponent and ISO TR 9464 methods for correcting the temperature at downstream/recovery point to upstream temperature

This standard calculates the upstream temperature from the downstream or recovery point temperature.


Upstream Temperature Calculation Method - Isentropic Exponent


When Temperature Exponent Method - 'User Entered' is selected the user inputted value for temperature exponent is used in the place of '1-Y/Y'

Upstream Temperature

Symbol Description Units
t1 Upstream temperature °C
t3 Temperature at the fully recovered pressure position °C
p1 Upstream pressure bar a
p3 Fully recovered downstream pressure bar a
Y Isentropic exponent -

Upstream Temperature Calculation Method - ISO TR 9464


When 'Downstream' is selected differential pressure(Δp) is used in the place of permanent pressure loss(Δω).

Upstream Temperature1

Symbol Description Units
t1 Upstream temperature °C
t3 Temperature at the fully recovered pressure position °C
Δt Difference in temperature °C
Δω Permanent pressure loss bar a
p1 Upstream pressure bar a