zCFD is a GPU-accelerated high-performance computational fluid dynamics (CFD) solver bridging the gap between commercial and open source.

zCFD is designed to make highly effective use of modern computer architectures. zCFD will run on unstructured meshes from a variety of sources, and will export data in many common formats. zCFD offers an easier route to coupling multi-disciplinary capabilities and integrating third-party data sources.

Features include both finite-volume and finite-element (high order DG) formulations, overset capability and fluid-structure interaction (FSI) running on both CPUs and GPUs, and allowing steady-state or time-dependent, turbulent flow simulation. The numerical scheme has been selected for accuracy and robustness. The code provides automatic scaling of turbulent wall functions; automatic determination of inflow / outflow conditions and automatic pre-conditioning to allow for low and high Mach number flow.

zCFD makes use of the MPI protocol to manage execution over a set of compute nodes. The execution process is completely parallel from the start to finish including all the Input/Output (IO) functionality. To support this scalable implementation the mesh input is provided in hdf5 format which is portable and self describing. Filters are provided to convert the most frequently used formats to this internal format.

zCFD uses a single control dictionary to specify all the parameters. This is a Python file containing a python dictionary with certain mandatory keys. The use of Python for the control dictionary enables the user to add custom functions that populate the dictionary at runtime.

The zCFD distribution includes a GPU-accelerated high performance Computational Aero-Acoustics solver (CAA), primarily aimed at broadband, aerodynamically generated noise. This is based on the high order Discontinuous Galerkin (DG) method which solves the Acoustic Perturbation Equations (APE) to predict noise based on aerodynamic sources. zCFD is a time domain solver therefore noise signals can be post-processed to provide narrowband and broadband spectra.

In order to generate aeroacoustic noise predictions, acoustic sources can be specified using a stochastic noise generation technique based on the Fast Random Particle Mesh (FRPM) method, alternatively, acoustic sources from high fidelity CFD simulations can be used.

To improve ease of use, the zCAAMesh mesh generator (included) will generate appropriate acoustics meshes, permitting optimum time steps, using the CFD surface mesh, thus eliminating further CAD cleanup and meshing effort by the user.

zCFD is a hybrid of an open-source (freely available without restriction) front-end (“zCFD Driver”) and proprietary (closed-source) back-end (“zCFD Core”). Anyone can develop “zCFD Driver” for their own purposes including commercial exploitation.