Physics-Based Modeling of Contrails Formation and the Interaction with a Turbulent Atmosphere

It is well-known that contrails form when hot exhaust from aircraft interacts with cold atmosphere, but the detailed hydro-thermodynamics of the process is still not well understood. The Schmidt‐Appleman criterion provides a means of determining the threshold under which contrails will form. However, the developments leading to this result are based on empiricism for the most part. In our work, a model is proposed for modeling air vehicle jet exhaust using a physics-based approach. Thus, if the jet phase is properly resolved as herein proposed, the dependence on parametrization will be obviated, leading to a more accurate and versatile simulation of the vortex phase of the problem. We numerically solve the flow field, defined by the relative difference between the high-speed exhaust jet and the ambient air, using a high-order Navier-Stokes solver. At the moment, the large-eddy simulation approach is followed, with a plan to explore solving with the Reynolds-averaged and direct simulation methods. The ice particles that are formed because of the condensation process are tracked in the Lagrangian fashion. Results on the trailing vortices and the structure of the contrails will be presented, as will the evolutions of temperature and water vapor mixing ratio and other important fields of the problem.