[TRNSYS-users] Equation and Amplitude of Type 501 Ground Temperature Profile

[Julian Röder]

I use the type 501 to calculate the soil temperature in a deep of 1.5
meter. The duration of the simulation is one year.

1.	Have anyone experience with Tess Model Type 501 and can acknowledge
that in the mathematical reference the equation is incorrect? I think the
alpha “Thermal diffusivity of ground” in the equation must standing under
the slash, the Time value tnow and tshift is using in the unit hr and the
365 in the equation must be written in 8760 hr.

Then you have results for T in the right unit and the results are
conforming to the type output. (Compare German “VDI 4640”, Part 4,
Equation 8)

2.	Is the Parameter 3 “Amplitude of surface temperature” the difference
between the annual average air temperature and the maximal average air
temperature of the months? For example: Tmean=8.8°C;  TJune=19.3°C; 
TJanuary =1.3°C than is the Amplitude Tamp=19.3°C-8.8°C=10.5°C
In this way the result make more sense as when the amplitude is calculate
with the amplitude of the maximum daily temperature Tmin= -12.3°C and
Tmax=31.7°C .


I hope to get answers.

Best regards


Julian Röder