Hi Joe,
I'm sorry I let this question slip by without an answer.
For the power tower models with a circular field, when you run the
optimization wizard
from the Heliostat Field page, SAM runs PTGen, which is an implementation of the DELSOL3 code.
The optimization wizard (PTGen/DELSOL3) calculates optimal values for the receiver diameter and height, tower height, and the field layout values (radial step size for layout, total reflective area, number of heliostats, and number of heliostats per radial zone.)
After you run the optimization wizard, you can adjust those values on the Heliostat Field page if you want to, and then run simulations to calculate the power tower system's electrical output.
In terms of the TRNSYS modules, their interaction is described in detail in Wagner 2008, which you can download from the
Performance Models
page. PTGen calculates plant geometry data, which the central receiver model (Type 222) and heliostat model (Type 221) use to model the system's hourly performance based on solar resource and ambient weather data from the weather file.
Best regards,
Paul.
