HydroComp Inc., of Durham, NH USA, is pleased to announce the release of NavCad™ to ver. 3.72. NavCad™ is a software product from HydroComp, Inc. for the prediction and analysis of speed/power performance. Widely used by the industry's professional design community, the development goals for this release were to strengthen its analytical capabilities for high performance vessels.
Resistance Prediction
A new resistance prediction method for high-speed transom stern vessels has been added. The HSTS method has proven to be a very capable method for semi-displacement hull forms in our own in-house use and testing.

Data Checking
Two important data checking enhancements have been made to NavCad™. First, an additional range check for the NavSea added seas drag method was developed and implemented. This helps insure against prediction problems associated with scale effect. Second, an additional range check parameter was developed and added for the Holtrop method. Anecdotal experience and testing by HydroComp have identified combinations of hull parameters that produce significant errors with the Holtrop method. This parameter has proven to be an indicator of these potential errors.

Minimum Drag Analysis for Planing Hulls
NavCad's parametric Minimum Drag Analysis has been extended to planing hulls. You can set up a matrix and investigate important planing hull parameters, such as chine beam, angle of deadrise, LCG, shaft angle and flap deflection.

Vessel Acceleration
Perhaps the most exciting new feature for this build is the analysis of vessel acceleration. For each entered speed, this new routine calculates the acceleration (in G's) and the time-to-speed (in seconds). This is not a simplistic evaluation, but is a first-principles iterative time-step approach which incorporates vessel added mass and the engine's torque curve, as well as engine RPM acceleration limits (i.e., slew rate), to accurately model real engine behavior and vessel performance. (This feature is available only in the Full version of NavCad. It is not available for the Small Ship version.)

HydroComp, Inc. provides software products and consultancy services for the performance analysis and design of marine vehicles to industry, research and government clients. Currently over 330 marine professionals in 34 countries worldwide are using HydroComp software.

For more information, please contact:

Nick Danese
Design Systems & Technologies
Tel +33 (0)4 92 91 13 24
Fax +33 (0)4 92 91 13 38
ds-t@ds-t.com
www.ds-t.com