How come some surfaces are not appearing in the boundary surfaces list?
In Maxsurf set the Surface Use to "Internal Structure" in case you want to use it as an tank boundary.
Tip: if you want to display your internal structure
surfaces in Hydromax, you can switch on the Internal edges in the
Visibility dialog from the Display menu.
Some of my tanks appear not to form correctly. What could be wrong?
What can be the case is that the tank is actually formed correctly, but in some situations the display of tank edges may not give a complete display of the shape of the tank. To check whether your tank is formed correctly, ensure you check the shape of your tanks by turning on the display of tank sections.
Is skin thickness included for Internal structure surfaces?
Skin thickness applied to internal structure surfaces is not taken into account when calculating the volume of Tanks and Compartments that use internal structure surfaces as boundaries. If you want to include the effect of the tank boundary surface's skin thickness, you have to model the surface to the inside of the tank.
The thickness of hull surfaces is taken into account. Remember to check the direction of the outside arrows when applying skin thickness.
My criteria dialog does not look good anymore, how can I fix that?
Holding down the shift key while firing up the criteria dialog, will resize the dialog to its original settings. You can then resize the dialog and change the division of the individual areas as described in Resizing the criteria dialog in the Hydromax manual (best viewed in Internet Explorer).
My tank calibration results read zero or 100% full for most of the intervals
Check your sounding pipes in the sounding pipes table. When your sounding pipes are set to User Defined and you move your tanks, the sounding pipe can become located outside of your tank. This will produce incorrect tank calibration results.
You can make sure your sounding pipes are in the correct location and of the correct length by setting them back to automatic in the Sounding pipes table:
I am getting a Criteria analysis error message when I run an analysis. What could be wrong?
The following criteria analysis errors can occur:
1: Severe wind and rolling
Make
sure your heeling range starts at -20 degrees or less. The roll back
angle to windward often requires the heeling range to start at a
negative angle.
2: MAX GZ in a range
Make
sure your upper limit of your heeling arm is set to > 90 degrees,
and check whether your MaxGZ value does not occur at an angle <30
degrees (the lower range bound).
There is no direct method of bonjean calculation in Hydromax.
However it is possible to get sectional area data at selected draughts:
Run an upright Hydrostatics calculation at the required draught and trim.
Go to the results table.
Select each draught in turn and choose "Display | Select view from Data"
Then go to "Window | Graph | Curve of Areas" -- this will bring the curve of areas to the front instead of the upright hydrostatics data, and is only required the first time.
Double click anywhere in the graph window to get the data table.
Copy and paste the first two columns into a spreadsheet.
Then close the dialog, go back to the results table, select the next draught, select "Display | Select view from Data", go back to the graph, double click, select, copy and paste the data -- repeat for each draught.
Tip:
If the windows are not maximised, you'll find it easier to switch between the results table and sectional area graph.
There are two different versions of Hydromax, which vary in price and capabilities, allowing you to select a product that suits your needs and budget.
Hydromax Pro is a powerful intact and damage stability analysis program with an extensive range of customisable stability criteria. It includes a built in weight and balance spreadsheet, tank calibrations, damage conditions and a range of hydrostatic analyses: o Upright Hydrostatics, o Large Angle Stability (GZ curve) o Equilibrium and Specified condition, o Cross curves of stability (KN), o Limiting KG, o Floodable length, and o longitudinal strength. Several analysis modifiers may be included such as a longitudinal wave form and grounding.
Hydromax has batch processing capabilities and a number of output options. In addition a VBA/COM interface is provided so that you can generate custom macros in (for example) Microsoft Excel which will perform an analysis and extract the results.
Hydromax/S is a simplified version of Hydromax providing only intact hydrostatics and stability functions: o Upright Hydrostatics, o Large Angle Stability (GZ curve calculation) and o Equilibrium analysis. Stability criteria cannot be evaluated and grounding is not included. There is no batch analysis mode either.
Please note that Formation Design Systems offers upgrades from Hydromax/S to Hydromax Pro for the difference in the current list price. This means that if you are using Hydromax/S and wish to upgrade to Hydromax Pro, we can email you the access code for Hydromax Pro and all you will be paying is the difference between Hydromax/S and Hydromax Pro.
Yes you can. When you save a loadcase you can specify the name of the loadcase. After you have saved the loadcase, you will see that the name of the loadcase appears at the top of the loadcase window as well as on the tab at the bottom of the loadcase window.
After a longitudinal strength analysis I get a graph, but my results table is empty. How do I get the results data?
The longitudinal strength analysis values in the results table are calculated at the design sections. Make sure you have defined sections in your model in Maxsurf. Without this, the longitudinal strength table will
be empty.
Note: you can also get the graph data values by double clicking on the curve and then copying and pasting the tabular data that appears into Excel. This can be done from any graph in the Maxsurf suite.
When I open my Maxsurf model in Hydromax, some sections are wrong. What should I do to fix that?
Remember that for Hydromax to work it must be able to form sections through the model. Any extra surfaces (or missing surfaces) that cause ambiguity will give Hydromax problems and may lead to Hydromax interpreting the model incorrectly.
The 4 key rules are:
At any longitudinal position, you must have non-intersecting, closed contours.
For a given longitudinal position, you can have a maximum of one opening and this will be closed by a straight line -- i.e. for a monohull its generally OK to leave the deck off.
You cannot have a contour completely inside another contour -- this type of feature (e.g. waterjet duct) needs to be modelled with a non-buoyant volume.
Surfaces which form vertical transverse planes are generally best avoided since a section at precisely the longitudinal position of the surface is undefined (it contains the whole surface not just a simple contour).
Hydromax can be used to analyse submarines. However, some analyses
require that the centre of buoyancy (CoB) and centre of gravity (CoG)
be balanced (Equilibrium and Stability analyses plus other analyses
that use these as a basis: Longitudinal strength, Cross curves and
Limiting KG). For these analyses Hydromax can be used provided that the
submarine is not fully submerged. These analyses require a waterplane
so that the CoB/CoG balance can be performed. As soon as the waterplane
area becomes very small or zero, Hydromax (and any other Hydrostatic analysis program that works on this principle) may have difficulty in
converging and the trim and heel cannot be determined. Upright
hydrostatics and some Specified condition analyses can be performed for
the fully submerged submarine.
In order to model the submarine, any volumes that are
free-flooding should be modelled as non-buoyant volumes, whilst ballast
tanks should be modelled as normal tanks.
Classification societies do not certify software that is used for design, analysis and production of stability booklets. In a design office you can use Hydromax without certification. It is the produced stability book that gets certified. See our Launchings pages for some examples of projects that have been successfully completed using Hydromax.
Classification societies only require software that is used on-board of a ship to be certified and then only the installation that gets installed on-board of that one particular ship (with one fixed hull form and compartment definition etcetera). Hydromax is quite suitable to be used for that purpose as well. If you are interested in us doing custom development for you, please contact us.
How can I calculate the TCB in Hydromax at different angles of heel?
This cannot be done directly in Hydromax, but attached is a spreadsheet
which will extract the data from a LAS analysis once completed using
the Hydromax COM interface.
Click the GetResults button in the
spreadsheet and it should populate the spreadsheet with data.
Have a look at the macro to get similar results from other analyses or for additional data.
Note
that there are two coordinate systems -- one is fixed in the ship
reference frame, the other is in a World coordinate system with
longitudinal and transverse parallel to the waterline.
It is possible to analyse certain hydrostatic properties of submarines using Hydromax. This is described in the Tips&Tricks section of this knowledge base which is accessible to Maxsurf users with current subscription.
The negative linked compartments are created by Hydromax automatically at the intersecting volumes of tanks and compartments. You do not need to worry about them at all; they are displayed for reference purposes only because in older versions users had to define these linked negative compartments manually. The linked negative compartments are used by Hydromax internally to deduct tank volumes from a compartments' volume when flooded, but again: you do not need to worry about them.
What restrictions does the demonstration version of Hydromax have?
The demonstration version of Hydromax only allows analysis on the one sample design that is opened automatically when you select the File |Open command. This model already contains a number of tanks and compartment as well as predefined damage cases, but feel free to add more and run some analyses.
Additionally, the demonstration version of Hydromax does not allow saving of reports or copying graph or table objects.
What Quality Assurance Processes are used to ensure that Hydromax produces reliable and accurate results.
Many Hydromax users ask us how we know that Hydromax produces
the correct results.The following
explains how FORMSYS has verified that Hydromax gives accurate
results and what steps we take to make sure that each version of the software
we ship is as reliable as possible.
Quality Principles While it is impossible to ensure that any software product
is completely free of bugs, we follow a series of engineering and testing
principles and procedures to ensure that Hydromax will produce results which
are consistent with the level of accuracy and thoroughness a professional
engineer applies to design work.To this
end we follow a development and testing path which includes use of structured
programming techniques, verification of the underlying algorithms, testing of
the computer implementation of those algorithms, testing of real world problems
in-house and beta testing in the field at Hydromax user sites.
Structured
Programming The best defence against bugs in software is to use
structured programming techniques that have been proven to improve software
reliability.Without going into the
technical details of our software development methodology, we summarize by
saying that we utilize structured code, object oriented design, data hiding and
encapsulation and fault tolerant programming practices to enhance our
software's reliability. Hydromax is a complex software system of over 400,000
lines of code and we believe our history of reliability reflects the effort we
have put into using reliable coding practices.
Verification of
Algorithms When new design or analysis algorithms are introduced into
Hydromax, we first carry out testing on the algorithms on Reference Designs –
these are proven test cases with known analytical solutions.
Reference Designs A folder of reference hull shapes is included with Maxsurf
and Hydromax. These designs are of simple geometric shapes and can be used to
validate calculations performed by Hydromax. Below is a table of results
derived analytically from these shapes compared with results obtained from
Maxsurf and Hydromax at different precisions.
Testing of
Implementation Once the basic algorithms have been proven correct,
testing is then carried out on more complex sample problems to which a solution
has already been established using a proven analysis program.These results may either come from Naval
Architecture and Marine Engineering texts such as well as from other results
carried out by Formation Design Systems or other engineers using other software
products such as NAPA,
AutoShip etc.
Testing of Upgrades As each new version of Hydromax is released we perform a
series of tests to ensure it functions correctly.At each release the results from these tests
are compared with the results from the previous release to ensure conformance
with answers which have been established as being correct.
Beta Testing Immediately prior to the release of each new version of
Hydromax, we conduct a beta test of the software.This involves sending the software to
practicing engineers and having them use it on design work in progress to
determine its reliability for actual design use.These beta testers provide us with feedback
on the reliability and accuracy of the program as well as its useability and
suitability for everyday work.Once the
beta test program is completed and all testers are happy with the program, we
begin shipping the commercial version.
Version Control Each new version of Hydromax displays a version number
indicating the version and the date the software was first shipped.If the version is a development, alpha test
or beta test release, the version number may also include a letter and number suffix
indicating the type and number of the release.A development version is usually only for internal use and is a very
early demonstration of a possible new product or feature.It is highly experimental and not reliable.
An alpha release is a first public release of a program for initial testing and
comment, it is not reliable.A beta
release is a final test version of the program released for field testing prior
to commercial release. It is mostly reliable but may contain some bugs.A commercial release is a completed, debugged
program reliable and ready for professional use. For example 1.0d1The
first development release of version 1.0 1.5a2The
second alpha test release of version 1.5 1.6b2The
second beta test release of version 1.6 1.64A
commercial release of version 1.64
But we're not
Perfect We make every effort to ensure that our software will meet
our users' needs and perform accurately.However, as with all complex software systems, it is possible for errors
to occur.If you suspect a problem with
Hydromax, please contact our technical support staff by email at
support@formsys.com and explain what you believe the problem to be.In the unlikely event of a problem being
found, we will correct it as soon as practicable, and send you a new corrected
version of the program.
To get accurate results from Hydromax, it is necessary for
you to model the problem correctly and to correctly interpret the results
produced. It is the users' responsibility to correctly model the structure and
assume responsibility for the results.
