Short Paper on improving the fuel efficiency of Ocean going vessels

1. Fuel
Optimization
for Ocean
going vessels
- generate the most accurate
Mathematical Model from source data
Capt. Oscar Rajendiran
+91 97907 31784
oscar_sarc@hotmail.com

2. Friction – detailed analysis
• Wind vector
• Ocean current
• Waves vector
• Swell vector
• Tidal current vector
• Wind current vector
• Water density*
• Water temperature*
• Hull friction*
oscar_sarc@hotmail.com

3. Data for generating CFD
Total number of data variables is 15 (5+2+2+3+3) *
Vessel
• Draft
• Trim
• List
• Heading
• Speed
Wind
• Direction
• Intensity
Current
• Direction
• Intensity
Wave
• Direction
• Height
• Length
Swell
• Direction
• Height
• Length
oscar_sarc@hotmail.com

4. oscar_sarc@hotmail.com

5. Typical Offshore DP Vessel Proposed for Ocean Vessels
All signal inputs go to onboard DP
Computer and Mathematica Model(MM)
is calculated on vessel.
Mathematical Model(MM) is
calculated ashore based on real-
time weather data and forecast.
MM is updated instantaneously as
and when signal feed is received.
MM is updated according to
frequency
of weather forecast. i.e. 2 / 4 /
6 hourly.
Works on the principle of minimum
thrust (as calculated) for
required station keeping.i.e.
stationary or moving.
Works on the principle of least
resistive path from point A to B.
Difference between expected vessel
position and actual position is
used back into the system as
‘Current Estimate’
and fed back into the MM as part
Difference between expected vessel
position and actual position is
relayed to shore team, this data
is used to
apply corrections to weather
oscar_sarc@hotmail.com

6. • Resistance Calculation
• This illustration is basis 3
directional possibilities (directions)
for every unit (leg).
• 9 possibilities to travel 3 legs.
• 9 Calculations.
• In reality the data variables are
15+
• And each data has it’s own data
range i.e. Vessel
 Draft: ballast ~ laden (20 pts)*
 Trim: head ~ stern (20 pts)*
 List: port ~ stbd (5 pts)*
 Heading: -10 ~ +10 (20 pts)*
 Speed: SSS ~ Full (10 pts)*
 TOTAL: ~75 pts*
• There is an exponential need for
heavy computing power to make
the difference from 3 to 74 pts.
• Then there are wind, current,
wave and swell with their own
variables and more pts to
calculate.
Vessel
1.Draft
2.Trim
3.List
4.Headi
ng
5.Speed
oscar_sarc@hotmail.com

7. Navigate – Least resistive path with least
water distance (minimal propeller slip)
Vessel travelling from A to B with 3
options for every unit (e.g. 100 NM)
Resultant path AFTER calculating
resistance along multiple legs/units and
multiple possibilities.
oscar_sarc@hotmail.com

8. At Present –
how are the
unusual
phenomena on
vessel
handled?
Master alters course and/or speed
It’s done on ad hoc basis
The degree of reaction varies from Master to Master / reaction is
totally unpredictable
Most cases (phenomenon) cannot be predicted and therefore
cannot avoid
In some cases – wrong action taken that could be detrimental in
terms of voyage length / fuel consumption / vessel damage etc.
In some cases – NO ACTION
oscar_sarc@hotmail.com

9. Interesting phenomenon that should be part of Virtual
Vessel Model that are very
-Vessel specific
-Draft/trim/speed/displacement specific (will be different
for the same vessel)
Pressure distribution along the hull
Vortex areas along shipside and conditions that cause it
Panting of vessel in specific sea conditions and how to mitigate it
Pounding of vessel in specific sea conditions and how to mitigate it
Synchronised rolling under specific conditions
All other unusual phenomenon that occur under specific
conditions of vessel and weather.
oscar_sarc@hotmail.com

10. Best case
1. Multiple PRS / DGPS
(accuracy up to
0.01m)
2. MRU installed
3. On board calculation
of MM with wind &
sea
4. Instant feedback on
position excursion for
corrective action
Present case
1. GPS (error up to
20m)
2. No MRU
3. Feedback every
24hrs
Proposal – short term
ZERO HARDWARE INVESTMENT
1. Torsional vibrational damper
data log
2. Heading log
3. Autopilot log
4. Drift test – calibrate#
5. Generate CFD / MM ashore
SMALL INVESTMENT
1. Digitize hull plans
2. Machine learning to
improve MM
3. Integrate all available PRS
with Kalman filter.
Proposal – long term
1. Independent PRS
(GPS/GLONASS/Galileo/BeiDou/
Regional systems)
2. Install MRU
3. Dual antenna GPS
4. Flow meter for fuel utilized
5. Digital vessel installed onboard

11. Present
Challeng
es that
can be
mitigate
d &
improved
Most vessels NOT operating at optimised
(at design) draft, trim or speed. Identify
the right combination for each specific
condition of laden / ballast, making minor
adjustments in draft and/or speed.
Fuel tables can be improved to maximize
accuracy.
oscar_sarc@hotmail.com

12. Potential
Future &
Commercial
aspect
Tankers and all other vessel types
Concept can include Alternate fuels for route
optimization
Can include all types of energy saving devices (ESD),
i.e., sails, rotors, kites retrofitted on vessels.
It is future proof – because the concept accounts for
every calorie and ANY fuel type.
oscar_sarc@hotmail.com

13. So, what’s the proposal?
Use existing technology to generate
Computerised Fluid Dynamics (CFD)
for vessels using minimal
investments and minimal time.
Use available data (yet not being
used) to generate more accurate
Virtual Vessel Models –
Mathematical Models.
Supplement the accuracy of data
prediction and machine learning
algorithms presently used.
FUN FACT - To generate 500 CFDs for
1 vessel using a high-end domestic
computer takes about 20 years.
oscar_sarc@hotmail.com

14. The missing
components to
generate accurate
data for MM
• Accurate 2D
vessel’s vector
interaction to
weather
• Accurate Position
Reference Systems
(PRS)
• Motion Reference
Unit (MRU)
How to compensate
without additional
hardware on vessels +
other Suggestions
• Torsional
vibrational damper
data log
• Rudder movement log
& Heading Log
• Auto-pilot setting
for the duration
• Calibration – drift
test
• Use Kalman Filter
on all available
PRS on board
• Digitalize hull
plans to enable
Capt. Oscar Rajendiran
+91 97907 31784
oscar_sarc@hotmail.com