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TRANSCRIPT
Scana Propulsion has utilized its long
experience and know-how in propeller
design and documented well the
performance of Scana Propulsion High
Efficiency nozzle (Scana HE nozzle).
The characteristics of the
Scana HE nozzle gives best
performance in bollard condition
and at higher speeds.
PROPULSION
CREATING PROGRESS
INCREASED THRUSTLOWER NOISE REDUCED SIZE
Scana Propeller Nozzles Optimizing propulsion efficiency by applying the best nozzle profile
Scana Propulsion AS // Scana Propeller Nozzles // [email protected] // www.scana.no // Rev 2 // 150415
UP TO 30% HIGHER
THRUST AT LOW SPEED COMPARED TO AN OPEN PROPELLER
Tailor-made propulsion for your vessel Optimizing the propeller for each individual vessel
Left: Typical example of propeller thrust with and
without nozzle at 100% MCR.
What does a nozzle do?
A nozzle increases the thrust at low speed. This is
essential for tugs, trawlers and anchor handlers. At
low speed, the thrust may be increased by up to
30% by using a nozzle propeller. A nozzle will also
give higher thrust to a vessel with blunt hull lines
and high wake.
Scana Propulsion AS // Scana Propeller NozzlesPage 2
Scana has utilized its vast experience in
evaluating the performance of the Scana
Propulsion High Efficiency nozzle compared
to the 19A nozzle which is considered to be
the market standard.
Bollard Pull
The Scana HE nozzle shows up to 5%
higher performance in bollard pull conditions
compared to the 19A nozzle. The reason for
this is that the profile of the Scana HE nozzle
has a bigger outer diameter than 19A nozzle
at the same propeller diameter.
Trawling
The performance of the Scana HE nozzle is
slightly better than the 19A nozzle in trawling
condition.
Low Transit Speed
At lower transit speed the 19A nozzle shows
higher performance than the Scana HE
nozzle. However, with increasing speed the
Scana HE nozzle improve its performance.
Additional in-depth information is available
for customers.
The Scana HE nozzle is specifically designed to increase the thrust from the propeller in bollard pull conditions
[email protected] // www.scana.no Page 3
37 nozzle profileThe 37 nozzle is recommended for vessels with high priority to astern performance. The forward bollard pull will be at the same level as for the 19A nozzle, but at higher speed the performance is not competitive compared to the 19A nozzle.
Pay special attention to the red area with flow separation at exterior side near the leading edge and the vorticity formation and detachment at the trailing edge. The flow separation shown reduces the efficiency. The blunter trailing edge contribute into higher form resistance of this duct type.
19A nozzle profileThe 19A nozzle is recommended for many installations since it has a good overall performance in different running conditions.
Pay special attention to the red area with flow separation at exterior side near the leading edge. The flow separation shown reduces the efficiency.
Scana HE nozzle profileThe Scana HE nozzle is recommended for ships with high bollard pull requirement, and low propeller loading at higher speed. The Scana HE nozzle has also better astern performance than the 19A nozzle.
Pay special attention to the vorticity formation and detachment at the trailing edge. The blunter trailing edge contributes to higher form resistance of this duct type.
High Transit Speed
The below illustrations show the water velocity distribution around the three different nozzle profiles in high transit speed. The Scana
HE nozzle shows significantly better performance than the 19A and the 37 nozzles. Both the 19A and the 37 nozzles show higher flow
separation which reduces the efficiency, and in addition the blunter profile of the 37 nozzle leads to higher form resistance.
During the evaluation process of the Scana HE nozzle several CFD (Computational Fluid Dynamics) calculations were made in
investigation of characteristics of the nozzle profiles.
Vast experience and know-how Configurable nozzle designs with over 100 years of propulsion experience
The information in this brochure contains, or may be deemed to contain ‘forward-looking statements’. These statements might relate to future events or our future financial performance, including, but not limited to, strategic plans, potential growth, planned operational changes, expected capital expenditures, future cash sources and requirements, liquidity and cost savings that involve known and unknown risks, uncertainties and other factors that may cause Scana or its businesses actual results, levels of activity, performance or achievements to be materially different from those expressed or implied by any forward-looking state-ments. All forward-looking statements made in this brochure are based only on information presently available in relation to the information contained in this brochure and may not be current any longer. Scana assumes no obligation to update any forward-looking statements. Nothing in this brochure constitutes invest-ment advice and this brochure shall not constitute an offer to sell or the solicitation of an offer to buy securities or otherwise to engage in any investment activity.
Pictured above: Scana tailor-made propeller in a Scana HE nozzle installed on an Anchor Handling Tug Supply Vessel
Over the last few years, Scana Volda has invested a lot in
exploring the scalable effects of nozzle propellers. From 2013
until 2016 we have been part of the Propscale Research
Project at Marintek.
One of the primary focuses in this project is the scalable
effect on nozzle propellers in different speed regimes and with
different propeller blade designs.
Affiliates such as the Technical University of Hamburg and
China Scientific Research Centre are also participating in this
project alongside the Norwegian community.
Up to 30% higher thrust at low speed
PRIMARY ADVANTAGES
Lower vibration and noise level in the ship
Less speed reduction in head sea/wind
Better course stability
Reduced optimum propeller diameter
Reduced size of propeller hub
Propscale