The potential effects of propeller-induced velocities (propeller wash or propwash) on the erosion, transport, and re-suspension of contaminated sediments can be significant. EEMS uses an integrated propeller wash sub-module that can utilize the automated information system (AIS) telemetry from vessels regarding their position and orientation every few minutes or any user defined ship track information.
Propeller Wash Setting in EE Forms.
The Propeller Wash module has been developed to simulate the impact of ship propeller jet on bed erosion and suspended solids. It is an important element in the development of plans for improvement and optimum utilization of waterways.
To activate this module, RMC on Modules from the Model Control form, then check on the box of Propeller Wash as shown in the Figure 1.
Figure 1. Activate Propeller Wash module.
RMC on the Propeller Wash module under the Modules option in the Model Control as shown in the Figure 2. The Propeller Wash form will be displayed as shown in the Figure 3. This shows the total number of ships and the number of tracks.
Figure 2. Edit Propeller Wash module.
The Propeller Wash form has three tabs consisting of: General, Ships, and Tracks tabs.
The General tab consists of General Settings, Mesh Settings and Model Parameters frames as shown in Figure 3. The Add Propwash Velocities option allows the user to add propeller efflux momentum to the ambient flow field.
Figure 3. Propeller Wash form: General tab.
When first opening the form to create a new model the Ships tab will be empty as shown in Figure 4. The user must fill in the information fields for the ships from Ship Info and Propeller Info sub-tabs. The MMSI Code and Ship Name fields are required to be filled first because those fields are essential indices. Click the Add Ship button and the ship is added to the List of Ships fame as shown in Figure 5. A new ship can be added by selecting Add New Ship from RMC's options as shown in Figure 6. Ships are distinguished by MMSI Code. If a user imports multiple files having the same MMSI, the points are simply appended to the existing ship track specified by the given MMSI.
Figure 4. Propeller Wash Form: Ships tab.
Figure 5. Propeller Wash Form: Add New Ship (1).
Figure 6. Propeller Wash Form: Add New Ship (2).
When the user clicks on the Ships tab, ships names will be displayed in the List of Ships. If the ship name is missing, the MMSI code will be displayed. After selecting a ship, the information for the selected ship will be presented in the Ship Info, Propeller Info, Tracks Info and Ship Management sub-tabs as shown in Figure 7.
Figure 7. Propeller Wash Form: Ships sub-tabs.
Figure 8 and Figure 9 illustrate terminologies and dimensions which relate to the propeller of a ship. These dimensions are used in EE forms shown in Figure 10 and Figure 11.
Figure 8. Propellers with Side view of a tugboat.
Figure 9. Propellers with back view of a tugboat.
Figure 10 displays general information for the selected ship such as MSSI Code, ship name, ship dimensions, number of tracks, etc.
Figure 10. Ships tab: Ship Info.
Figure 11 displays propeller information for the selected ship such as the number of propellers, number of propeller blades, propeller diameter, etc.
Figure 11. Ships tab: Propeller Info.
Figure 12 displays track information for the selected ship such as number of tracks, track begin and track end time in Julian days, number of points in each track, etc. The Delete Current Track will remove the current track.
Fill Missing Data frame:
Interpolate Missing Data
Compute Heading, Course & Speed
Extrapolation
Overwrite All Values
Set Value
Figure 12. Ships tab: Tracks Info.
Figure 13 displays ship management for all ships listed. The user can select ships based on criteria in the Ship Selection frame by selecting a parameter from the drop-down list then select Comparison and Target Value. The criteria will be applied for the Select From and Select Options below, then click the Select button to proceed. The result is that ships that meet the selection criteria will be highlighted on the List of Ships.
Number of Selected Ships: for the ships selected from the List of Ships, the number for selected ships will be displayed (e.g. 3). For these ships, the user can assign a value for each field from the drop-down list using the Assign button. In addition, the missing fields can be filled by using online data using the option of downloading data from Vessel Finder or Marine Traffic sites. The online downloading process will apply to each ship in a step-wise manner.
Figure 13. Ships tab: Ship Management.
Figure 14 displays three options for editing ship information including Add Ship, Delete Ship, and Update Ship. The Add Ship allows the adding of a new ship to the ships list, while Update Ship is used for saving the information of ships when the user changes or update fields in the Ship Info sub-tab. Delete Ship is used to remove ships from the ships list.
Figure 14. Ships tab: Add, delete, update options.
When you select a ship from the List of Ships then RMC, a number of options will be displayed as shown in the Figure 15, including the following options:
Remove Selected Ship(s): will delete the selected ship
Remove All Ships: will delete all existing ships in the list
Move Up: move the selected ship up
Move Down: move the selected ship down
Order Name by Ascending: will sort the ships list with the lower ID numbers will be at the top of the list and letters sorted is alphabetically from A to Z.
Order Name by Descending: will sort the ships list with the larger ID numbers will be at the top of the list and letters sorted is alphabetically from Z to A.
Add New Ship: add a new ship to the list. Once this option is selected, a duplicate ship will be added to the bottom list of ships as shown in Figure 16. The user should LMC on another ship then LMC back on the duplicate ship and then enter information for the new ship including propeller information. Click the Update button when after completing filling this information, then click the OK button to save the information of the new ship.
Figure 15. Ships tab: Right Mouse Click options.
Figure 16. Ships tab: Add New Ship.
Figure 17 shows the All Tracks tab, this tab can be used for filling missing data of tracks, split tracks and delete tracks.