A method to compute ship exhaust plumes with waves and wind

作者：Huang Juntao; Carrica Pablo M; Stern Frederick^*

来源：International Journal for Numerical Methods in Fluids, 2012, 68(2): 160-180.

DOI：10.1002/fld.2499

• exhaust plume
• thermal and solution transfer
• free surface flow
• ship hydrodynamics and aerodynamics
• waves and winds

Thermal and concentration transport models are implemented in CFDShip-Iowa version 4.5, a semi-coupled solver for air/water free surface flow (Int. J. Numer. Meth. Fluids 2008; 58(6):591624), to investigate the exhaust plume around ship superstructures. An incompressible, variable density approximation is implemented where the density can change in all governing equations due to temperature variations only. The thermal and concentration models are tested for the cases of steady and unsteady flow with thermal and solution transport in a 2D square cavity, and for a 3D thermal plume in an open environment, showing good agreement between computational results and experimental data. To test the method in an extreme motions condition, the exhaust plume of the ONR Tumblehome model DTMB 5613 is studied, showing complicated vortical structures in air including a pair of counter-rotating vortices downstream of the stack for cross-flow, and bended bird-plume shape in the symmetry plane and varying arc-shape in axial sections both for temperature and NOx concentration fields. Effects of smoke exhaust speed and wind speed on the temperature and concentration distributions are studied. Finally, a smoke downwash computation is performed for a ship free to move in 6 degrees of freedom in a sea state 8 condition.

• 出版日期2012-1-20