Seminarium w Języku Obcym
(j. angielski)
Kierunek - M
Wydział Mechaniczny - 2016
Outline of the lecture No. 1
© Mirosław Gerigk
1. An implementation area of the innovative small ships and unmanned
maritime objects. An impact of the implementation area on a small ship
(unmanned object) basic parameters and hydromechanic characteristics.
2. The most important phenomena affecting a small ship (unmanned object) motion on the
water surface. An influence of the particular conditons on the small ship (unmanned
object) motion.
3. The principles of modelling of a small ship (unmanned object) motion.
4. A mathematical model of a small ship (unmanned object) motion in the real operational
conditions. The equations of flow. The equations of motion.
5. Some remarks on the computational models.
6. A methodology of design of the innovative small ships and unmanned maritime objects.
7. The applications.
ASSESSMENT OF PERFORMANCE
AND
SAFETY ASSESSMENT
OF
UNMANNED MARITIME VEHICLES
Mirosław K. Gerigk
Politechnika Gdańska
[email protected]
PRESENTATION OUTLINE
1. Introduction
2. Integrated muli-task navy system. Novel small multi-task ships
3. Novel surface/underwater vehicles (drones). Design challeges
4. Assessment of performance of an unmanned object moving in
two specific operational conditions
5. Risk assessment for an unmanned for a surface/underwater
vehicle
6. Conclusions
1. Introduction
Advanced manned vehicles:
- surface vehicles
- wing in ground vehicles
- underwater vehicles
Aron-7
Virgin Oceanic
Advanced unmanned vehicles (maritime drones, water drones):
- surface vehicles
- wing in ground vehicles
- underwater vehicles
- surface/underwater vehicles (water drones)
MIT
SeeByte
DARPA
What does it mean an advanced (novel vehicle ?...  V.Bertram, O. M. Faltinsen
1. Introduction
Problems:
Problem 1: development of multi-task ships (BSM, BSL)
-
The possible solutions:
mono-hull,
catamaran,
trimaran,
ACV, SES.
Problem 2: development of advanced (novel, autonomous - intelligent)
surface/underwater vehicles (ZBSM).
Problem 3: development of multi-task ships (platform) integrated with
advanced surface/underwater vehicles
1. Introduction
Background for the research and design: idea, solution (design), team
of specialists, decisions (risk), resources, advanced research and design
Approach to R&D: holistic, legislative
R&D of the objects:
1) Features of novel ships/vehicles:
- stealth,
- Performance,
- safety,
2) Parameters and characteristics (performance, design, hydrodynamics):
floability, stability,…, steering and control, sub-systems, safety.
2. Integrated muli-task navy system. Novel small multi-task ships
Project RP-NAVY:
Źródło: opracowanie własne
2. Integrated muli-task navy system. Novel small multi-task ships
Project TRIMARAN:
Trimaran:
- L: 16 / 24 m
- B: 8 / 12 m
- BT: 5 / 3 / 2,4 m
Project SEMI-SUB-STEALTH:
Stealth ship:
- L: 60 m,
- B: 8 m,
- v: 30 węzłów.
Źródło: opracowanie własne
3. Novel surface/underwater vehicles (drones). Design challeges
Unmanned vehicles (BSM):
- underwater vehicles (BSM-P),
- surface vehicles (BSM-N),
- advanced underwater/surface vehicles (ZBSM).
Displacement of UV (BSM):
•small: <1 t
•medium: 1-100 t
•large: 101-1000 t
•extra large: > 1000 t
Draught of UV (BSM):
•shallow: < 300 m
•medium: 301-999 m
•deep: 1000-5999 m
•extreme depth: > 6000 m
Źródło: opracowanie własne
3. Novel surface/underwater vehicles (drones). Design challeges
Project SUB-STONE:
L: 6,2 m
B: 2,4 m
H: 1,1 m
Project HYDRO-SUB:
L: 4,7 m
B: 2,7 m
BT: 1,6 m
Projekt HYDRO-CV (FIST-RP):
Źródło: opracowanie własne
3. Novel surface/underwater vehicles (drones). Design challeges
Project BHSOW:
L: 4.9 m
B: 5.2 m
BT: 2.4 m
M: 0.95 m
Project DELTA:
Źródło:
Źródło:opracowanie
opracowaniewłasne
własne.
3. Novel surface/underwater vehicles (drones). Design challeges
Project FIST-RP (ZBSM):
Źródło: opracowanie własne
3. Novel surface/underwater vehicles (drones). Design challeges
Źródło: opracowanie własne
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Methodology (I):
The main objective of the current research is to work out a functional model of
the advanced AUMO object which should be able to move on the water surface with
a different range of speed.
Assumptions: The advanced AUMO object could move above the water
surface for a short period of time. The flight height should be less than 5 meters.
The AUMO object should have a special power system supply enabling to work for at
least 30 minutes up to a few hours before the new energy supply.
The methodology of the research is based on the holistic approach. The
implementation of this approach to the design and to the construction and operation
of the AUMO object in the future is novel.
The research method combines the performance-oriented approach with the riskbased approach.
The research problems associated with development of a concept of the AUMO
object moving in two specific operational conditions are associated with four major
tasks: object definition, assessment of object performance, object steering and
control, safety assessment of the object.
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Methodology (II):
First of all the AUMO object performance should be assessed. This is connected
with estimation the floatability, stability, resistance and propulsion characteristics first
of all.
The performance characteristics are the base for assessment of the steering and
control of the object including the maneuverability and seakeeping.
The performance assessment is the base for the risk assessemnt as well. This
should be done for the data operational conditions and sequence of events under
consideration.
After that the safety assessment of the AUMO object may be done.
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Method:
Start
Safety objectives
Standard design objectives
Design requirements, criteria, limitations
Risk acceptance criteria
Limitations concerning the costs and benefits
Design/operation
Hull form
Ship/aircraft
Loading conditions
Natural
environment
Aircraft/ship and environment
definition
Wind
Waves
Accident categories
Hazard identification
Modification of design or
operational procedure
Arrangement of
internal spaces
Another
Hazard assessment
Stranding
Identification of accident scenarios
Risk
control
options:
-prevention
-reduction
-mitigation
Collision
Ranking the
hazards,
Risk acceptance
criteria
Estimation of the
probability of hazard
occurence Pi
Estimation of
accident
consequences Ci
Risk assessment:
Is risk tolerable?
No
Assessment of aircraft/ship
performance in:
- undamaged conditions
- damaged conditions
Risk estimation
Ri = Pi * Ci
Yes
Models of risk
Costs/benefits analysis
Yes
Are costs too high ?
No
Choice of optimal design or
operational procedure
Pi, Ci, Ri – concerns the
iterations in respect to
all the possible events
accident scenarios
System of making the decisions on the object
safety in undamaged/damaged conditions
End
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Method:
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
A concept of object operation:
The major assumptions concerning the advanced AUMO object have been defined
as follows:
- deployment from a helicopter or naval platform,
- take off from the water surface for a short distance flight, then land on the water
surface,
- submerge and transit underwater (an advanced version III),
- loiter for up to one hour fully submerged.
Basic requirements:
Crew
unmanned
-
Minimum flight range
15
miles
Maximum flight range
50
miles
Average flight height
3.5
meters
Take-off speed
40
knots
Maximum cruise speed
90
knots
Submerged transit
10
NM
Loiter
1
hour
Submerged speed
5
knots
Maximum operating depth
30
meters
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
The AUMO object definition: a hybrid mono-hull including the hull form and
arrangement of internal spaces,…
Analysis:
- object definition
- weight and centre of gravity estimation (materials, sub-systems, etc.)
- performance assessment
- steering and control
- risk assessment
- safety assessment
The problem of estimating the weight (initial investigations):
- weight of all the materials including the weight of skin plates and main frames,
- weight of the propulsion system,
- weight of all the sub-systems and equipment,
- weight of the payload.
The design drivers (sub-systems):
- air-jet propulsion sub-system,
- water-jet propulsion sub-system,
- power supply sub-system,
- ballast sub-system,
- air supply sub-system,
- hydraulic sub-system,
- steering sub-system,
- communication and navigation sub-system
- multi-task patrol sub-system or combat sub-system.
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Particular research and design problems:
The design drivers (sub-systems): air-jet propulsion sub-system, water-jet propulsion subsystem, power supply sub-system, ballast sub-system, air supply sub-system, hydraulic sub-system,
steering sub-system, communication and navigation sub-system, multi-task patrol sub-system or combat
sub-system.
Three variations of the object were developed offering a different arrangement
based on the same overall design concept.
The key features of the design concept were as follows:
- hold is a fully watertight pressure compartment,
- fuel tanks are incorporated into the hull space,
- ballast tanks are incorporated into the hull space,
- volume within the wing is floodable,
- fuel and ballast tanks incorporated into the wing is considered with the tanks containing a
membrane compensation system,
- twin turbofans provide the power for the surface operations,
- turbofan sealing is using the new torpedo door style hatches,
- an innovative float system is applied for take-off and landing operations,
- propulsion for the underwater operations is provided by a battery,
- ballast system is equipped with a pressure air system to blow the ballast tanks and floodable
areas.
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Object performance:
1) planning plate theory,
2) wing in ground theory,
3) computational fluid dynamics (CFD), finite element method (FEM),…
Seaworthiness of the AUMO object. It should be understand as a certain
maximum wave height for take-off, cruise and landing. From the practice point of
view the seaworthiness of the AUMO object should be defined by the take-off wave
height and the landing wave height, where the latter may be predicted higher. The
installed power should be determined by the maximum wave height at take-off. The
structural strength of the hull should be determined by the maximum landing wave
height where the highest sea loads occur.
Power mismatch. For the AUMO object the drag in the take-off run should be
much higher than the drag at the short cruise speed. Therefore the engines must
be sized for the take-off and run on a lower of about 30-40 % power in cruise. This
is difficult to use the extra power in cruise for increasing the cruise speed. There is
a maximum safe speed above which the AUMO object may be become unstable.
This may be undesirable to overpower the AUMO object.
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Take-off drag. The power mismatch may be solved by minimising the take-off drag.
The drag during the take-off consists of several contributions. The main players are
the hydrodynamic viscous and wave pattern drags. The viscous drag is due to the
friction between the wetted surface of the hull and the water. Wave pattern drag is
the energy that is lost due to formation of a wave pattern on the water surface. The
hump drag determines the installed power (see this in Figure). The theoretical
maximum speed that the AUMO object may reach is the point where the thrust and
drag lines meet (see the Figure).
D, T
T
D
vto
vmax
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Take-off speed. It is necessary to apply a sophisticated wing and flap design for
creating as much lift as possible at the take-off in order to reduce the take-off speed,
hydrodynamic loads and drag. It is possible to rotate the object so that the angle of
attack at the take-off is much higher than that in the cruise flight. It means that the lift
coefficient at the take-off may be up to 10 times higher than in the cruise flight. The
object cannot take full advantage of flaps. A new solution is proposed.
Minimising take-off power. The take-off power is determined by the take-off drag.
So the drag must be minimized. Since drag increases with the speed squared the
take-off speed should be minimized. But for a given aerodynamic configuration and
weight the minimum airborne speed is fixed.
Therefore the drag may only be decreased by optimizing the way the hull generates
its lift or introducing the other lift sources.
The two main ways to carry the loads are the hydrodynamic lift and aerostatic lift.
The hydrodynamic lift can be generated by the hull.
The aerostatic lift may be delivered by the air injection or a static air coushion.
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Hull design. It is important to look at the hull design as a source for improving the
take-off performance. Of course, the aerodynamic design still becomes very
important. A distinguished design of the hull enables to increase the hydrodynamic
L/D factor. It is possible to use the steps, chines and ventilation. The steps help to
decrease the wetted area and prevent the hull from "sticking" to the water. The
chines can be very helpful in suppressing the spray and thus spray drag. The friction
drag may be reduced by forcing the air into the step or even through small holes in
the hull bottom, this is called the ventilation or air lubrication.
It may be clear that hydrodynamic hull design is not a simple task. The
proposed AUMO object is just aerodynamically very sophisticated, but
aerodynamically still to be improved. This is the opposite way like the WIG designers
normally do.
Considering the aerodynamic characteristics of the AUMO object the following
problems should be taken into account:
- influence of the wing span dominated ground effect,
- influence of the wing chord dominated ground effect,
- influence of the wing lift L, wing drag D and L/D ratio,
- influence of the wing on the object longitudinal stability,
- influence of the ground effect wing sections.
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
A concept of the AUMO object
The 2nd and 3rd versions (designs) of the AUMO object have the main
parameters as follows:
-overall length L - is equal to 5.8 meters
-operational breadth B - is equal to 5.2 meters or 6.0 meters, depending on the wing
system applied
-breadth during transport Bt - is equal to 2.4 meters
-height H - is equal to 1.1 meters
-mass is equal to from 0.8 tons to 1.6 tons, depending on the weight of equipment
installed,
-maximum object speed on the water surface vws - is equal to 15 meters/seconds,
-maximum object speed above the water surface vws - is equal up to 35
meters/seconds
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Remarks on the computational model
The simulation is based on the RANS (Reynolds Averaged Navier-Stokes) flow
model, implemented in STAR-CCM+ solver. Simulation of flooding phenomenon
includes the following problems:
•Taking into account the presence of free surface and the oil (multiphase flow);
•Solving the motion equations for the floating body;
•Dynamic (i.e. moving) mesh; the floating object covered with the computational
mesh is moving during the simulation, so the nodes of mesh, in which the flow is
being solved, need to move also;
•Simulating the waves.
A computational model: STAR CCM+
- RANSE (Reynolds-Averaged Navier-Stokes Equations)
- VOF (Volume of Fluid)
- mesh
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Multiphase flow
    i  ci
i
c
i
1
i
Free floating of the object
Dynamic mesh
Types of dynamic mesh
by FOEST and CTO S.A., - Ship Research and Shipbuilding Centre
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Computational mesh details: transversal section of the domain
by FOEST and CTO S.A., - Ship Research and Shipbuilding Centre
4. Assessment of performance of an unmanned object moving in two specific
operational conditions
Siatka „przegubowa” (sliding mesh)
by FOEST and CTO S.A., - Ship Research and Shipbuilding Centre
5. Risk assessment for an unmanned for a surface/underwater vehicle
Risk:
R i =PC
i
i
Consequences following the occurrence of
the data hazard and scenario development,
in terms of fatalities, injuries, property losses
and damage to the environment
Probability of occurence of a given hazard
The risk of not surviving the collision:
Consequences:
-human related (injuries, fatalities)
-related to property
-related to environment
Probability of collision
R=PC PF C PS F C CC
Probability of sinking
New model of the
risk of killability
- 31-
PS F C =PoC
5. Risk assessment for an unmanned for a surface/underwater vehicle
Performance approach  risk assessment:
φ
Stochastic process
S(ω)
φ
2
t
f(φ)
ω
PoC 
 f  d
1
dφ
by FOEST
The PoCdam probability can be estimated during the accident at sea using the
following methods [1]:
- binary method
- method based on definition of the probability of surviving a…
- method based on definition of the data hydrodynamic charactristic under consideration
- 32-
5. Risk assessment for an unmanned for a surface/underwater vehicle
FOEST hybrid method of assessment of risk of not surviving a collision:
HMOZS
R  PC PF / C PS / F / C C C
where:
PS/F/C =PoC
HMOZS 1 – ”binary approach”
A ship has survived – risk R = 0
A ship has not survived – risk R = 1
HMOZS 2 – ”damage stability approach”
PoC  PCD  pA1  k A 2  

f
A1
Density functions
x  f A x dx
Atua K., Ayyub B.M. (1997)

Probability of damaged ship capsizing
HMOZS 3 – ”performance of damaged ship approach”
φ
S(ω)
φ
2
t
by FOEST
- 33-
Stochastic process
f(φ)
ω
PoC 
 f  d
1
dφ
6. Conclusions
The research presented in the paper is associated with the investigations and
design of advanced unmanned objects for the military applications (an option: civil).
The research concers the objects which seem to be much more advanced than
those under consideration in the past.
The key factors from the research and design point of view are the tasks the
objects are devoted to perform, materials, propulsion systems, steering and stealth
technology.
The aim of the paper was to introduce some information following from the
research associated with development of a new generation of the unmanned objects
moving on the water surface in two specific operational conditions.
The current research is associated with further development of the details of
problems presented in the paper.
The concept of the AUMO object is investigated by the author since 2010.
Some parts of the latest work on the AUMO object development is associated with
the research carried out by the Ph.D. students since 2012. More advanced
research has started despite a lack of large scale of finance support is
continued by a team of specialists and researchers from the different Polish
Universities and Research Institutions.
Thank you
dr hab. inż. Mirosław Gerigk, prof. nadzw. PG
Politechnika Gdańska
[email protected]