  Internal gravity waves (IGWs) can cause mixing in the radiative interiors of
stars. We study this mixing by introducing tracer particles into two -
dimensional (2D) hydrodynamic simulations. Following the work of Rogers &
McElwaine (2017), arXiv:1709.04920, we extend our study to different masses (3
M$_{\odot}$, 7 M$_{\odot}$ and 20 M$_{\odot}$) and ages (ZAMS, midMS and TAMS).
The diffusion profiles of these models are influenced by various parameters
such as the Brunt-V\"ais\"al\"a frequency, density, thermal damping, the
geometric effect and the frequencies of waves contributing to these mixing
profiles. We find that the mixing profile changes dramatically across age. In
younger stars, we noted that the diffusion coefficient increases towards the
surface, whereas in older stars the initial increase in the diffusion profile
is followed by a decreasing trend. We also find that mixing is stronger in more
massive stars. Hence, future stellar evolution models should include this
variation. In order to aid the inclusion of this mixing in one-dimensional (1D)
stellar evolution models, we determine the dominant waves contributing to these
mixing profiles and present a prescription that can be included in 1D models.
