Investigations of 3D turbulent flow inside and around a water-jet intake duct under different operating conditions

In this paper the flow field in the intake duct of a model water-jet unit i s studied by using a commercial 3D CFD code. In order to model the intake d uct/hull interaction, the computational domain includes a large section of the hull in the vicinity of the intake duct opening. Appropriate boundary c onditions are used on the far upstream and downstream of the duct inlet in order to minimize the effect of the domain boundaries on the flow field in the vicinity of the intake duct. Computations are performed for different b oat speeds and flowrates. In addition, the effects of the impeller shaft, s haft rotation, boat trim as well as the traverse flow across the hull are i nvestigated. The results of the computations are compared with some prelimi nary experimental results obtained from model self-propulsion tests in a to wing tank. Good correlation is obtained between the predictions and the exp erimental results.