Numerical simulation method for flows about a semi-planing boat with a transom stern

A new simulation method based on computational fluid dynamics (CFD) is deve loped for a semi-planing boat with a transom stern in unsteady motion. The time-dependent Reynolds-averaged Navier-Stokes (RANS) equation is discretiz ed by the finite-volume method and solved by the MAC-type solution algorith m. The free-surface treatment in this study is based on the density-functio n method. The motion of the boat is simultaneously solved by combining the equation of the motion of the boat with the flow computation, and the effec t of the boat motion is implemented by the moving grid method in the flow c omputation. Simulations for two types of practical high-speed boats are per formed in the Froude number range from 0.5 to 1.0 and the results are compa red with experimental ones. It is demonstrated that this method can simulat e both the flow about the boat and the running attitude in free-to-run cond ition with a sufficient degree of accuracy and that it can be used as an ef fective tool for the development of hull form of practical high-speed boats .