Required for all elements having geometric properties.
2 5 7 11 16 21 31 41
- --- -- ---- ----- ----- --------- --------- --------
|X| | | |XXXXX| | | | ...
- --- -- ---- ----- ----- --------- --------- --------
| | | | | | |
| | | | |-----------------------
| | | | |
| | | | |_(3)6 Geometric parameters (6F10.0)
| | | |
| | | |
| | | |_(2)Geometric Group Number(I5)
| | |
| | |_(1)ELEMENT Type(A4)
| |
| |_Optional User Identifier(A2)
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|_Compulsory END on last data record in data category (A3)Continuation Data Record - Only required for Morison elements. It may be omitted if the appropriate default values are required (see (4) and (5) below).
2 5 21 31
- --- -- ---- ---------- ---------- ---------
|X| | |CONT|XXXXXXXXXX| | |
- --- -- ---- ---------- ---------- ---------
| | | | |
| | | | (5)Added Mass Coefficient(F10.0)
| | | |
| | | (4)Viscous Drag Coefficient(F10.0)
| | |
| | |_Indicates Continuation of above Data Record(A4)
| |
| |_Optional User Identifier(A2)
|
|_Compulsory END on last daa record in data category (A3)
(1) The Element Type (always four characters) provides the classification for a particular element. This must correspond to the element type which references the geometric group number on the Element Topology Data Record in Data Category 2. Valid codes for element types in this data category are TUBE, STUB, DISC and PMAS.
Note: QPPL, TPPL and PBOY do not have any geometric properties.
(2) Geometric group number - This number is referred to in the Element Topology Data Record (Data Category 2) and is the index to the values given in columns 21-70 (2).
(3) Geometric parameters - Any element on any structure whose geometric group number corresponds to that given in columns 16-20 (2) has up to 6 of these values associated with it. A summary of the properties appropriate to each element is shown below. (Units are consistent with the physical quantity defined by each parameter.)
(4)/(5) Viscous drag/added mass coefficient associated with elements having hydrodynamic properties in the Morison regime. If the continuation data record is omitted, or if either field is left blank, or if zero value is input, default values are used for the appropriate element type. These values are shown below in Columns 7 and 8.
| Element Type | Basic Data Record | Continuation | ||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| TUBE | Diameter | Thickness |
0. Sealed 1. Open | Cut 1 | Cut 2 | X-direction drag coefficient Cd X (4) | Translational drag coefficient Cd (4) | Translational added mass coefficient Ca (4) |
| STUB | Effective diameter normal to Y-direction (2) | Effective diameter normal to Z-direction (1,2) | Area | Y-direction drag coefficient Cd Y (2,4) | Y-direction added mass coefficient Ca Y (4) | X-direction drag coefficient Cd X (4) | Z-direction drag coefficient Cd Z (2) | Z-direction added mass coefficient Ca Z (4) |
| PMAS | Ixx | Ixy | Ixz | Iyy | Iyz | Izz | ||
| DISC | Diameter | Cd (3,4) | Ca (3,4) | |||||
If omitted or set to zero, defaults to value 1 (effective diameter normal to Y-direction).
The Z-direction is defined by the third node in the element definition (data category 2).
The following figure describes the geometry for the slender tube element:
See Properties of Typical Morison Elements in the Aqwa Theory Manual to see how these coefficients are used within the program.
If omitted, the default values of the coefficients of the Morison elements are as below:
TUBE Cd X = 0.016 Cd = 0.75 Ca = 1.0 STUB Cd X = 0.016 DISC Cd = 1.14 Ca = 1.0 The slender tube’s default values are estimated based on the tube’s geometry, Cd Z = Cd Y and Ca Z = Ca Y.