COSA code

The CFD Optimized Structured multi-block Algorithm (COSA) code is a two- and three-dimensional Eiler/Navier-Stokes finite volume Computational Fluid Dynamics code developed and maintained by Dr. Campobasso and his research group. COSA and its pre- and postprocessing interfaces are being designed with a particular emphasis on open rotor and other fluid machinery unsteady aero- and hydrodynamics. Applications for which the code is particularly well suited and is being intensively used include horizontal and vertical axis wind and tidal turbines, and oscillating wings for tidal power generation. The code is also used for external wing aerodynamics; for example, it has been recently used for analyzing the impact of vortex generators on the performance of fixed wings in a Master project. COSA is under continuous development and with no or minor extensions it can also be already used for helicopter rotor, gas and hydraulic turbomachinery analysis and, ultimately, design.

One of the strongest points of COSA is an extremely efficient distributed-memory parallelization of both its computing core and its input/output functionalities. This enables highly accurate analyses of formidably complex unsteady flows in turnaround times of less than 24 hours even when using computational grids with 50 million cells and over. Other crucial features of COSA enabling a wide range of its application include an effective harmonic balance solver for the rapid solution of highly nonlinear periodic flow problems, and a robust low-speed preconditioner enabling the solution of both high-speed flows and low-speed, incompressible and mixed-speed flow problems.

A significant part of the recent research work of Dr. Campobasso and his group is based on COSA, and the code is also being increasingly used by national and international collaborators. The material below summarizes the main algorithmic and modelling features of COSA, and the main characteristics of its parallelization, and provides a sample of validation test cases used during its development.

Numerical method

Harmonic balance solver

Low-speed preconditioning


Sample validation

Interested in COSA? Researchers and engineers interested in using COSA can contact Dr. Campobasso for discussing the use of this software.