In order to increase the applicability of Cart3D to subsonic and transonic applications, we are developing an interactive boundary-layer method that provides a viscous model to Cart3D's Euler solver. The implementation subscribes to the philosophy of automation and efficiency of Cart3D's original Euler method.

The IBL plug-in improves accuracy by offering three boundary-layer solvers to address different types of geometry components, including wings and fuselages. A quasi-simultaneous coupling algorithm promotes speedy convergence and robustness. An advanced elliptic solver propagates the boundary-layer solution between 2-D boundary-layer strips and exhibits improved accuracy over traditional solvers. The IBL offers accuracy approaching that of Navier-Stokes analysis for many airfoils, wings and full configurations, while maintaining Cart3D's automation, robustness and speed. This feature is coming soon.

We will soon introduce a new version of Cart3D that is capable of adjoint-driven, mesh adaptation. Users will be able to obtain the best possible steady-state, invisicid solution with respect to a user-provided metric such as lift, drag, etc. Once the user has specified a target metric and a target accuracy for the metric, the adjoint module for Cart3D will be able to adaptively refine the mesh to meet those targets. The adjoint module improves efficiency; the mesh remains coarse in regions that do not have to be refined to obtain the desired accuracy for the specified metric and the user no longer needs to perform mesh refinement studies to obtain a quality solution. Also, the adjoint module improves accuracy, often necessarily refining the mesh in areas that even experienced CFD specialists may not consider important. Indeed, the adjoint-driven mesh adaptation process will revolutionize the way engineers obtain quality, inviscid solutions.

We recently released our first beta graphical user interface for Cart3D. The interface allows users to visually stage and transform geometry components. The GUI performs geometry tests and notifies users if they have staged invalid geometry. The flow solving interface plots residuals and forces on the configuration. A post-processer can quickly plot data contours on the surface geometry. It also calculates and displays force and moment coefficients. The interface allows the user to run Cart3D locally, or remotely.