New capabilities for fast craft analysis with ... - Hydrocomp Inc.

HydroComp, Inc.
September 30, 2013
HydroComp NavCad ® Released
Nearly three years of development in this latest NavCad upgrade
HydroComp NavCad is software for resistance and propulsion that can be found in the
toolbox of naval architects and marine professions from around the world. First
introduced in 1988, NavCad has undergone numerous upgrades in its 25-year history. But
none of the previous upgrades are more significant and exciting than those found in this
newly released version of NavCad.
More than just an upgrade for current users, the new NavCad 2013 establishes a
framework for ongoing feature development and improvements in the user experience.
The design for this framework was first sketched out in early 2010. The mandate from
HydroComp’s management was simple: to add capabilities and reliability, but in a way
that simplifies the process and increases user confidence. After nearly three years of
development and user testing, the new NavCad fulfills that mandate.
New technical capabilities
HydroComp has an active internal research and development program with the objective
of delivering new capabilities for NavCad and HydroComp’s other software products.
Many of the R&D projects are in direct response to end-user requests or HydroComp’s
own assessment of new industry requirements. Some of the projects are subtle, and
improve existing calculations. Others are profound and offer new capabilities where none
have existed before.
Substantial effort has focused on new tools for planing hull prediction. Built upon a
steady-state equilibrium of forces and moments, NavCad’s planing hull analysis now
provides for the definition of hull warp, influence of propulsor lift, as well as improved
trim tab contributions plus new support for interceptors.
Figure 1 – Planing hull developments
Resistance prediction is more than just bare-hull drag, of course, so new capabilities for
added drag prediction can be found in NavCad. A few examples include extended
definition and drag prediction for appendages, addition of spray drag for both planing and
fast displacement hulls, and a new “Workboat” added seas drag prediction.
The first of a number of “supplemental” prediction methods have been added for NavCad
2013. The first of these is support for submarines and SWATH vessels.

The biggest additions to NavCad for propulsion analysis are the new system prediction
for contra-rotating propellers (CRP), support for non-standard nozzle geometry, and new
prediction for high-performance propellers. This is supplemented by improvements in
propeller sizing and alignment to propeller model tests.
Increasing user confidence
Forecasting vessel resistance and propulsion performance is a lot like forecasting the
weather. In the absence of direct past experience, engineers will apply margins that may –
or may not – be appropriate and necessary. Unnecessary margins can reduce the overall
effectiveness of a design to meet its mission. So, NavCad now provides new utilities to
build user confidence in the predictions.
Users can define “benchmark” vessels for graphical comparison on NavCad’s new
“Confidence” plots for resistance, power, and propulsor efficiency. On these plots, vessel
category “confidence lines” set down historical “best case” minimum drag and power
limits. This feedback can be very useful to confirm that the entire system analysis is
proper and reasonable.
Figure 2 – “Confidence: PBTOTAL” plot
Updated interface and enhanced user experience
NavCad now has an improved interface, offering procedural directives and guidance. The
arrangement of the principal data entry and display groups will be easily recognized by
NavCad users. Leveraging its current layout, NavCad adds a more attractive tableoriented
data entry, as well as optional color themes to clarify data grouping.
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A new common file format was developed for all HydroComp products for 2013. It is a
text file based on the JavaScript Object Notation (JSON) syntax. Of course, full export
and import is supported for legacy NavCad files, as well as for data from other sources.
Figure 3 – HydroComp NavCad interface
About HydroComp
Celebrating its 29th year of operation in 2013, HydroComp provides software and
services for the performance analysis and design of marine vehicles to industry, research,
academic, and government clients. The company is proud to have served over 700
customers from more than 60 countries.
For more information, please contact:
Donald MacPherson, Technical Director
HydroComp, Inc.
13 Jenkins Ct, Suite 200
Durham, NH 03824 USA
Tel (603)868-3344
Fax (603)868-3366
dm@hydrocompinc.com
www.hydrocompinc.com
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