Calibrating the Mixing‐Length Parameter for a Red Giant Envelope

Abstract

Two-dimensional hydrodynamical simulations were made to calibrate the mixing-length parameter for modeling red giants' convective envelopes. As was briefly reported in a recent paper by Asida & Tuchman, a comparison of simulations starting with models integrated with different values of the mixing-length parameter has been made. In this paper more results are presented, including tests of the spatial resolution and large-eddy simulation terms used by the numerical code. The consistent value of the mixing-length parameter was found to be 1.4 for a red giant of mass 1.2 M_☉, core mass 0.96 M_☉, luminosity 200 L_☉, and metallicity Z = 0.001.