|
The models here represent
a collection of the vessels we have worked with over the years. While
some of the models are quite detailed, assembled with the benefit
of lines, plans and compartment descriptions, most of the models are
not so sophisticated. Each time we come across a vessel we
do not have, we add it to the library. However, we never include
models or information if it is known to be proprietary.
Most of the vessels you can use have an option to use either
strip theory or 3d diffraction when computing sea pressures.
By default, strip theory will be used. If, however, you put
the command:
&set diftype = 3ddif
before you "insert" the model, then 3d diffraction will
be used.
By default no wind or drag attractors are included in
these models. You can, however, add they by using the
variables V_CUR or V_WIN.
If V_CUR exists, then the option
-CS_CURR .2*%V_CUR %V_CUR %V_CUR
will be added to the piece definition. Likewise
if V_WIN exists, then the option
-CS_WIND %V_WIN %V_WIN %V_WIN
will be added to the piece definition.
Please feel free to use these models as you see fit.
We make no claims as to the accuracy of them,
and provide these for the general benefit of everyone.
We solicit your comments and contributions to this library.
To use one of the true models in this library, you simply include
the command:
USE_VES "NAME"
in your data.
Here, NAME is the name of the file containing the vessel model.
This command will automatically load the model and in many cases
this is your entire root.dat file.
Select one of the following to see what is available.
Here is a list of some marine operators:
Adding Models:
The vessel library system is structured so that you can add your
own models to it. To do so, however, you need to follow a few
rules. Once you have prepared a model you should store it in the
directory pgmpat/data/local, where pgmpat is the path to
the directory where the Ultramarine software is stored. Models in
our library have more structure than a typical MOSES model. By doing
so, we can use them with the automated tanker analysis and jacket
installation macros.
One thing to remember here is that you are building a model which may
be used in many different contexts. You will be setting variables which
will be used later, so that you cannot simply set them in any set of
units you wish. The top of each of our models contains the lines:
&if &info(bl) .ne. 'feet' &then
&set bigl = &number(real 1./3.28)
&set litl = 25.4
&else
&set bigl = 1.
&set litl = 1.
&endif
&dimen -save -dimen feet kips
&model_def -save
The purpose of these commands is to set the variables bigl and litl.
These server as conversion factors between the "user selected" units
and those which you will use. The last line instructs MOSES to
"save" the user selected units and to set feet and kips as the
units which will be used to define the model. If you are going to
define the model in SI units, your definition should be:
&if &info(bl) .ne. 'meters' &then
&set bigl = &number(real 3.28)
&set litl = &number(real 1./25.4)
&else
&set bigl = 1.
&set litl = 1.
&endif
&dimen -save -dimen meters m-tons
&model_def -save
The last commands in your model should be
&dimen -remember
&model_def -remember
which switches the units and defaults back to what they were at the
beginning.
Variables:
The next part of the model is to set some basic variables that other
tools will use:
&set vname = VNAME
&set ves_type = barge
&set lwa_ok = .false.
&set cmp_ok = .false.
&set flex_ok = .false.
&set v_npref = *b@
&set vdepth = &number(real %bigl%*DD)
&set vbeam = &number(real %bigl%*BB)
&set vlength = &number(real %bigl%*LLL)
The first of these defines a name for the vessel. The next one defines
the type of vessel, e.g. barge, tanker, crane, etc. The next three
describe the detail of the model you are defining. The variable
lwa_ok is set to .true. if you will define launch ways, otherwise,
it is set to .false. The variable cmp_ok is set to .true. if you
will define a compartmentation model, otherwise set it to .false.
The variable flex_ok is set to .true. if you will provide a
structural model of the vessel, otherwise it is set to .false.
The variable v_npref defined the prefix for all nodes in the
structural model. You should define at least one point with this
prefix even if you have no structural model.
The last three
variables vdepth, vbeam, and vlength define the length, beam, and
depth of the vessel in "user selected" units.
Light Ship Weight and Hydrostatics:
Next you should define the lightship weight of the
vessel with a command:
#WEIGHT LSHP 0.32*BB 0.29*LLL 0.29*LLL -CEN XXX YYY ZZZ -cat l_ship
Then you can define a "normal" MOSES model for the exterior and
perhaps compartments. As stated above, there must be one point defined,
but there is no limit to the structural model you may define.
Launch Ways:
If, and only if, you are defining a launch barge, you need to
define the geometry of the launch ways. These are defined by the
variables:
&set BLWAY = &number(real %bigl%*0)
&set TPRIHEI = &number(real %bigl%*8)
&set TSECHEI = &number(real %bigl%*0)
&set TSDIST = &number(real %bigl%*0)
&set XTPIN = &number(real %bigl%*332)
&set TBLENp = &number(real %bigl%*50)
&set TBLENs = &number(real %bigl%*50)
&set DEPSKD = &number(real %litl%*48)
&set HEISKD = &number(real %bigl%*(20+48/12))
&set maxasubm = &number(real %bigl%*31)
&set blwn_p =
&set blwn_s =
Here,
- blway defines the beginning of launch way,
- tprihei defines the tilt beam depth at pin,
- tsechei defines the secondary tilt beam depth,
- tsdist defines the distance from primary pin to secondary one,
- xtpin defines the distance from bow to the primary tilt pin,
- tblenp defines the length of the primary tilt beam,
- tblens defines the length of the secondary tilt beam,
- depskd defines the depth of skid beam (in inches or mm),
- heiskd defines the height of top of skid above the keel,
- maxasubm defines the maximum allowable keel submergence.
- blwn_p and blwn_s define selectors for the nodes which connect
to the port and starboard launch ways
Finally for a launch barge, one needs to include the two commands:
&describe load launch
&apply -percent launch 0
#amass DISP 0.06 0.10 3.50 32 200 55 -CEN X Y Z
#drag DISP .01 .2 1.7 3 1.7*LENG/3.46 .2*LENG/3.46 -CEN X Y Z
&describe load %vname
These are used for added mass and damping of the barge during a
launch. Here, the number DISP is the nominal displacement of the
barge at the beginning of the launch, L is the length of the
barge, and X, Y, and Z are the coordinates of the CB. you can
click here to look at a copy of the sample.
Use "save as" to save a copy.
Ultramarine, Inc. | Suite 325 | 3100 S. Gessner | Houston, Texas 77063 | (713)975-8146
Site Map
Copyright(C) 1996-2008 Ultramarine,Inc.
|
|
