Animal Representation Deck Representation

5.1 Animal Representation

The representation of animals within the computer models incorporates the following physical effects: Fluid blockage blockage to the deck air flows by the animal’s presence Energy source from skin Energy source from breath Moisture mass source from skin Moisture mass source from breath Momentum source from breath action at the mouth Geometrically, each animal is represented as a prismatic object located some distance above the deck floor. Key dimensions were chosen to be representative of typical real animals ie. height, length, overall surface area. Using such simplified prismatic bodies enables a more efficient meshing discretisation of the computational domain. One major issue for consideration was the space and proximity of adjacent animals. In most instances meshing would have proved much more difficult, if not impossible, if more curvilinear or ‘organic’ animal geometries had been implemented. Numerous such geometric animal models are positioned on each modular deck tier. Packing orientation and density for the initial runs has been chosen to be representative of typical conditions. Animal breath is simulated by drawing in ambient air at the side of the head, heating it, adding moisture, and then emitting it as a steady continuous air jet from the mouth. Typical thermodynamic data to be used in the modelling of the animals has been collected from numerous sources and rationalised to be self consistent.

5.2 Deck Representation

Each deck tier itself is modelled as a floor and roof only no side rails but includes provision for horizontal supply jets at each end. Roof beams are modelled as 2D blockages projecting down from the ceiling. A half-aisle has also been included to enable repetition of the same deck module across the width of the ship. Periodic boundary conditions used on each deck module will enable taller and wider model assemblies to be readily meshed and run. A variety of detailed ship drawings have been reviewed to determine the generic deck geometry used.

5.3 Summary of CFD Results