  Turbulent Radiative Mixing Layers (TRMLs) form at the interface of cold,
dense gas and hot, diffuse gas in motion with each other. TRMLs are ubiquitous
in and around galaxies on a variety of scales, including galactic winds and the
circumgalactic medium. They host the intermediate temperature gases that are
efficient in radiative cooling, thus play a crucial role in controlling the
cold gas supply, phase structure, and spectral features of galaxies. In this
work, we develop an intuitive analytic 1.5 dimensional model for TRMLs that
includes a simple parameterization of the effective turbulent conductivity and
viscosity and a piece-wise power-law cooling curve. Our analytic model
reproduces the mass flux, total cooling, and phase structure of 3D simulations
of TRMLs at a fraction of the computational cost. It also reveals essential
insights into the physics of TRMLs, particularly the importance of the viscous
dissipation of relative kinetic energy in balancing radiative cooling as the
shear Mach number approaches unity. This dissipation takes place both in the
intermediate temperature phase, which reduces the enthalpy flux from the hot
phase, and in the cold phase, which enhances radiative cooling. Additionally,
our model provides a fast and easy way of computing the column density and
surface brightness of TRMLs, which can be directly linked to observations.
