Flow Characteristics of air-caps for tank ventilation in ships

Ergin S.

11th International Congress of the International-Maritime-Association-of-the-Mediterranean (IMAM 2005), Lisbon, Portugal, 26 - 30 September 2005, pp.643-650 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • City: Lisbon
  • Country: Portugal
  • Page Numbers: pp.643-650
  • Istanbul Technical University Affiliated: Yes


Air-caps or tank vent check valves are employed in ships to allow tanks to breath during filling, draining and volume variations caused by thermal changes. A numerical study of flow in such a tank venting air-cap is performed to investigate turbulent flow and pressure drop characteristics. The method is based on the fully conserved control-volume representation of fully elliptic Navier-Stokes equations. The computational grid is established by employing the non-orthogonal body-fitted coordinate system and associating them with the multi-block to handle the complex geometry. Turbulence is simulated via two equation (k-epsilon) model. The study comprises computed velocity, the kinetic energy of turbulence and pressure drop distributions for three different sizes of air-caps. For each of these cases, the Reynolds number of the air-cap was varied from about 10(4) to 4.0 X 10(6).