CFDShip-Iowa is general-purpose computational fluid dynamics (CFD) simulation software developed at the University of Iowa’s IIHR—Hydroscience & Engineering. CFDShip-Iowa represents, in part, deliverables for sponsored research funding from the Office of Naval Research.

The program solves the incompressible Reynolds-averaged Navier-Stokes (RANS) and continuity equations with a variety of turbulence models, and a single-phase level set method to accommodate free surface problems. It is based upon structured grids and higher-order finite differencing and has both patched-grid and ghost-cell block-to-block communication. Complex geometries are treated using overset grids, by interfacing with the overset interpolation codes Pegasus (NASA) or Suggar (PET-ARL). Motions are possible by using dynamic overset grids through Suggar. The code is parallel and runs under MPI.

CFDShip-Iowa is fully general and has been applied to a range of external flow problems. Boundary conditions, input parameters, and grid dimensions are set external to the code. Since it has been specifically developed for surface-ship and marine-propulsor flow problems, it has an array of ship hydrodynamic specific subroutines and post-processors. Typical applications in naval hydrodynamics include Resistance (friction and pressure drag), Wave Profiles (including breaking waves), Seakeeping (the code is 6DOF capable), and Maneuvering (a mix of imposed and predicted degrees of freedom is possible). Additional capabilities include propeller models; multi-object interaction; and regular and irregular waves.