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TMR4225 Marine Operations, 2007.01.11

• What are you expecting to learn from todays lecture?

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TMR4225 Marine Operation

• My objectives for this lecture:– Establish a commen knowledge on operational

parameters for different types of underwater vehicles

– Obtain a commen understanding of critical phases in a mission for an underwater vehicle

– Document basic understanding of dominant flow regimes during different phases of a mission for underwater vehicles

– Introduce motion equations for submarines and AUV (streamlined bodies)

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Lecture form

• Presentations

• Buzz groups– Short questions

– 2-3 minutes discussions

– Oral presentation of buzz group results (keyword form)

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Nomenclature

• SNAME H-10 Panel• ITTC standard notation for manoeuvring

• Forces and moments: X,Y,Z K, M, N• Yv force coefficient for sway speed• Yvv is sway force due to sway speed, a linear damping

force due to angle of attack of the vehicle

• A more compact notation can be obtained by using a vector/matrix formulation of the equations of motion

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Axis systems

• Earth fixed system

• Vehicle fixed system– Right handed system

– X-axis forward

– Z-axis downwards

• Positive deflection of control flaps/rudders are clockwise

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Buzz groups Question 1

• In what layers of the ocean space are each of the vehicle types used?– Manned submarine

– AUV

– ROV

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Buzz groups Q1 answer:

• Manned submarines:– 300 m waterdepth ( large military ones operates at larger depths)

– 11000 m extreme pressure vessel design (Trieste), sea space exploration

– 3000 m exploration of sea bed

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Buzz groups Q1 answer:

• AUVs– 500 meters

– Military use, mine search 150-200 m

– Offshore, mapping 3000 – 4000 m

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Buzz groups Q1 answer:

• ROVs– Use close to structures

– Not used in the wave zone

– Depth limited by umbilical, down to 1000 m?

– Near the bottom, 1000 – 5000 m

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Flow characteristics for standard operations

• Submarine in transit– Streamlined body

– Mostly turbulent flow

– Constant transit speed

– Small perturbations, i.e. Sway/yaw/heave/pitch/roll speeds and angles of control planes

– Close to surface (periscope depth), in the wave zone

– Close to the seabed (interaction effect?)

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Flow characteristics for standard operations

• AUV– Streamlined body

– Constant transit speed

– Small perturbations, i.e. Sway/yaw/heave/pitch/roll speeds and small angles of control planes

Or:– Zero/very low speed

– Large angles of attack from current

– Thrusters for hovering/position keeping

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Flow characteristics for standard operations

• ROV– Non-streamlined body

– Mostly turbulent flow due to separation on edges

– Low speed

– Large angles of attack; have to be able to operate in cross current

– Different characteristics for up and down motion

– Complex flow due to interacting thrusters

– Umbilical drag can be high for operations at large depths

– Tether management system can be used to remove umbilical

induced motion of ROV

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Types of submarines

• Military submarines– Norway Ula class (dimensions?)– Typhoon type– Viking project – Nordic submarine

• Cargo carrying submarines– Bulk carriers (coal, LNG, oil)– Intervention vehicles for subsea oil and gas production– Russian Lazurit project

• Tourist submarines– Tropical waters– Amusement parks

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Buzz groups Question 2

• Discuss why no submarine bulk carriers have been realized?– Groups 1, 3, 5, …

• Discuss why non of the concepts for subsea oil and gas production submarines have been realized?– Groups 2, 4, 6, ….

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Buzz group Q2 answer:

• Bulk carriers– Great risks, consequences if something happens (rescue)– Environmental problems, especially if nuclear powered– More power then for surface vessels due to larger wet surface (for

large slow speed bulk carriers 80-90% of resistance is viscous)– Load carrying capacity restricted due to increased steel weight– Too expensive to build and operate (high quality steel, redesign of

shipyards, scraping costs, ….)– Separate terminals, high investment costs– Complex loading/unloading systems– Maintenance process must be modified– No need for this solution for ice free waters

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Buzz group Q2 answer:

• Submarines for oil and gas subsea structure installation and maintenance– No advantages compared to ROVs

– Not useful as diver platform for large depths

– High costs, both for vessel design/production and initial structure design to fit capacities of submarine

– No oil company is willing to be first user of a system based on submarine intervention

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Submarine summary

• Submarines are hydrodynamically well designed

• Commercial use of submarines is at present no alternative for subsea oil and gas production

• May be role for submarines infuture Arctic oil and gas exploration and production

• Development of military submarines will continue, but not at the same level as before

• Submarines for tourism will expand

• Manned vehicles will be used for exploration of the ocean space

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Submarine motion equations

• 6 degrees of freedom equations

• Time domain formulation

• Simplified sets of linear equations

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EUCLID Submarine project

MARINTEK takes part in a four years multinational R&D programme on testing and simulation of submarines, Euclid

NATO project “Submarine Motions in Confined Waters”. Study topic:

Non-linear hydrodynamic effects due to steep waves in

shallow water and interaction with nearby boundaries.

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TMR4225 Marine Operations, 2007.01.11

• Sum up the 3 most important learning outcomes of todays lecture

• Have your expectations been fulfilled?– If not, why not?

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SHEFEX recovery mission

• During a sounding rocket campaign at Andøya Rocket Range in October 2005 the 300 kg payload SHEFEX was lost

• Estimated impact zone was 70,3443 North and 12,1508 East

• Water depth at impact zone is approximately 2700 m

• Prepare a plan for the recovery mission

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From outer to inner space