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Propeller Tunnel

MaritimeThis functionality requires the Maritime add-on to be enabled. 5.4.0This functionality requires CAESES version 5.4.0 or later.

The Propeller Tunnel component is part of the Ship Modeling Workflow and is accessible via the Maritime tab (MaritimeThis functionality requires the Maritime add-on to be enabled.) in the Model workspace. It belongs to the modeling workflow for the ship type Hard Chine Boat. This component represents the addition of a single or a twin propeller tunnel to the hard chine hull geometry.

Model Structure​

This model is divided into three main scopes:

  • 00_parameters: Contains all Design Variables and the Parameters define the geometry of the spray rails relative to the main boat dimensions.
  • 01_geometryCurves: Contains all Curves needed for the propeller tunnel generation.
  • 02_surfaces: Contains all Surfaces needed for the propeller tunnel generation.
  • 03_brep: Contains the negative volume of the BRep This will trim the hull and will create the huill geometry with the propeller tunnel.

All design variables are located in the scope where they are first used. Their names are chosen to clearly describe their functionality, and their bounds are tested to ensure model robustness. The Hard Chine Boat workflow allows users to modify values, object types, and even the overall model structure for maximum flexibility.

Hull with Propeller Tunnel

Inputs Taken from Hard Chine Boat​

The following inputs are automatically taken from the Bare Hull and Hull Parameters components:

Propeller Tunnel Input

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Both the Bare Hull and Hull Parameters components are required in order to create the Propeller Tunnel component.

Single or Twin Propeller Tunnel​

The parameter N defines the number of propeller tunnels created within the component. Two options are available during creation: a single propeller tunnel (N = 1) or twin propeller tunnels (N = 2), as shown below.

Propeller Tunnel Options

The geometric differences between these two options are illustrated below.

Single & Twin Propeller Tunnel

Parameters​

The 00_parameters scope is divided into three sub-scopes:

  • 00_absoluteDimensions
  • 01_relativeDimensions
  • 02_derivedDimensions

The Design Variables placed within these sub-scopes control the geometry of the Propeller Tunnel component and are shown below.

Parameters of Propeller Tunnel

All design variables are continuous, except for roundedInlet, which is a Boolean variable taking the values True (1) or False (0). Its effect is illustrated below.

Rounded Inlet Effect

Geometry Curves​

The two main Geometry Curves used for generating the negative BRep volume (later applied to trim the hull geometry) are ProfileStart and ProfileEnd. These curves lie on the transom and on the bottom of the hull, respectively.

Geometry Curves of Propeller Tunnel

Surfaces​

The Surfaces used to generate the negative BRep volume for trimming the hull geometry are shown below. These surfaces are created using the Geometry Curves defined in the previous scope.

Surfaces of Propeller Tunnel

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To achieve a clean cut with the hull, the surfaces are extended slightly outward from the transom and downward from the bottom of the hull.

BRep​

The final negative BRep for the propeller tunnel, named tunnel_negativeVolume, can be found in the 02_brep scope. It is generated from the surfaces in the previous scope. After trimming the hard-chine hull with this BRep, the final tunnel geometry is obtained.

Hull with Propeller Tunnel