Qualitative Investigation of Transom Stern Flow Ventilation

The transom stern is a popular design choice found in all types of marine vessels. The truncated shape is very popular with naval combatants, is found on high speed commercial ferries, and is wide spread in the recreational market for planing boats. Several advantages of this design feature include weight savings, manufacturing efficiency, and possible resistance reduction in the speed range of vessel operation. The presence of the transom stern while providing operational benefits, introduces new challenges for the designer to predict performance characteristics. The stream wise discontinuity in the hull geometry either creates a viscous “dead-water region”, or with sufficient speed, allows for clean separation of the flow. Present numerical methods can provide useful results when a judgment of the condition of the flow behind the transom is made before the calculation begins. The purpose of this work is to begin a study into the nature of transom ventilation including its inception.