  Arkenstone is a new model for multiphase, stellar feedback driven galactic
winds designed for inclusion in coarse resolution cosmological simulations. In
this first paper of a series, we describe the features that allow Arkenstone to
properly treat high specific energy wind components and demonstrate them using
idealised non-cosmological simulations of a galaxy with a realistic CGM, using
the Arepo code. Hot, fast gas phases with low mass loadings are predicted to
dominate the energy content of multiphase outflows. In order to treat the huge
dynamic range of spatial scales involved in cosmological galaxy formation at
feasible computational expense, cosmological volume simulations typically
employ a Lagrangian code or else use adaptive mesh refinement with a
quasi-Lagrangian refinement strategy. However, it is difficult to inject a high
specific energy wind in a Lagrangian scheme without incurring artificial
burstiness. Additionally, the low densities inherent to this type of flow
result in poor spatial resolution. Arkenstone addresses these issues with a
novel scheme for coupling energy into the ISM/CGM transition region which also
provides the necessary level of refinement at the base of the wind. In the
absence of our improvements, we show that poor spatial resolution near the
sonic point of a hot, fast outflow leads to an underestimation of gas
acceleration as the wind propagates. We explore the different mechanisms by
which low and high specific energy winds can regulate the SFR of galaxies. In
future work, we will demonstrate other aspects of the Arkenstone model.
