Suggestion of an update of the equilibrium tide model
#506 opened on Feb 7, 2025
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Description
The current method for incorporating the effects of the equilibrium tides on small convective regions near the stellar surface relies on an approximate calculation of the eddy turnover timescale, adapted from Hurley et al. (2002), based on Rasio et al. (1996) (Eq. (7) of the Posydon v1 paper).
I am concerned about the applicability of this approximation for very small convective zones. Indeed, in the limit Mconv.reg → 0 (which also implies R_t,conv.reg − R_b,conv.reg → 0), the formula yields a zero turnover timescale, leading to a null synchronization timescale.
A more self-consistent alternative could be to use the local value of the turnover timescale (maybe an average over the considered convective region), which can be obtained directly from the structure in the mixing-length framework.
Luca Sciarini