nmass

N-DOF thermal model of connected nodes

Functions

nmass.calc_model(pars, states, times, T0s, msids, dt=328.0, max_dwell_ksec=200, cache=False, state_only=False)

Calculate temperatures for given states and initial temperatures T0s, and model parameters U, Ue, P.

The states input must be an iterable list with the following keys::

tstart tstop pitch

Solve for dT/dt = A T + B where T is a vector, A is a tri-diagonal matrix and B is vector.

For reference the 2-dof model calculates:

dT0_dt = U01 * T1(t) + P0(t) + U0e * Te - (U01 + U0e) * T0(t)
       = U01 * (T1 - T0) + P0 + U0e * (Te - T0)
       = U01 * (T1 - T0) + (P0 + U0e * Te) - U0e * T0
where T1 is the coupled node temperature and U0e is the external coupling.

Looking at the last equation there is a degeneracy with P0(pitch) and U0e * Te. So T_e is actually always frozen at 0.0 and U0e * Te gets slurped into P0:

dT0_dt = U01 * (T1 - T0) + P0 - U0e * T0

To add an internal power term (e.g. for ACIS modeling):

dT0_dt = U01 * (T1 - T0) + P0(pitch) + C0 * P_int(state)  - U0e * T0