TMR4225 Marine Operations, 2004.01.16 What are you expecting to learn from todays lecture? Responses are collected in a separate word document

TMR4225 Marine Operations, 2004.01.16 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 Documented basic understanding of dominant flow regimes during different phases of a mission for underwater vehicles

Examples of: Submarines AUVs ROVs Work tasks for AUVs and ROVs TMR4225 Marine Operations, 2004.01.16 Examples of: Submarines AUVs ROVs Work tasks for AUVs and ROVs

Lecture notes: Submarines, AUV – UUV and ROV Present version contains Submarines and AUVs Ch. 4 on ROVs will be available 2004.03.05 Notes includes web links, some may be rotten, some may be static and a few good ones are dynamic If you know of other web sites that have relevant content on subsea vehicles, send me an e-mail One vehicle will be used as a reference case for AUVs and ROVs repectively

Lecture form Presentations Buzz groups Work groups Short questions 2-3 minutes discussions Oral presentation of buzz group results (keyword form) Work groups Work task related questions 5 minutes discussions Written presentation of work group results (keyword form/basic drawing)

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 usinga vector/matrix formulation of the equations of motion

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

Buzz groups Question 1 In what layers of the ocean space are each of the vehicle types used? Manned submarine AUV ROV

Buzz groups Q1 answer: Manned submarines: 300 m waterdepth ( large military ones) - 11000 m extreme Trieste, sea space exploration 3000 m exploration of sea bed/

Buzz groups Q1 answer: AUVs 500 meters Military use, mine finding 150-200 m Offshore, mapping 3000 – 4000 m

Buzz groups Q1 answer: ROVs Use close to structures Not used in the wave zone Depth limited by umbilical, down to 1000m? Near the bottom, 1000 – 5000m

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

Flow characteristics for standard operations AUV Streamlined body Mostly laminar flow Constant transit speed Small perturbations, i.e. Sway/yaw/heave/pitch/roll speeds and angles of control planes Or: Zero/very low speed Large angles of attack from current Large angles of attack on control planes or heavy loads on thrusters

Flow characteristics for standard operations ROV Non-streamlined body Mostly turbulent flow due to separation on edges Low speed Large angles of attack Complex flow due to interacting thrusters Umbilical drag and induced motion on the ROV

Types of submarines Military submarines Cargo carrying submarines Norway Ula class (dimensions?) Cargo carrying submarines Bulk carriers Intervention vehicles for subsea oil and gas production Tourist submarines Tropical waters Norwegian coastline

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, ….

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

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

Submarine summary Submarines are hydrodynamically well designed Commercial use of submarines is at present no alternative for subsea oil and gas 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 deeper parts of the ocean space

AUV overview AUV definition: UUV definition: A total autonomous vehicle which carries its own power and does not receive control signals from an operator during a mission UUV definition: A untethered power autonomous underwater vehicle which receives control signals from an operator HUGIN is an example of an UUV with an hydroacoustic link

AUV/UUV operational goals Military missions Reconnecaince Mine hunting Mine destruction Offshore oil and gas related missions Sea bed inspection Pipe line inspection Sea space and sea bed exploration and mapping Mineral deposits on sea floor Observation and sampling

Offshore oil and gas UUV scenario Ormen Lange sea bed mapping for best piperoute trace Norsk Hydro selected to use the Hugin vehicle Waterdepth up to 800 meters Rough sea floor, peaks are 30 – 40 meter high Height control of Hugin to ensure quality of acoustic data

Group work spring 2003 SIN TMR4240 Marine Control Systems Future scenario for operation of a subsea oil and gas production system No surface operation Subsea Operational Centre Central landbased Operation Centre Short presentation of some of the group deliverables WG1 Path control and docking of AUV WG3 Intervention between subsea installation and AUV/ROV WG6 Multiple AUV operations for pipeline tracking

Phases of an AUV/UUV mission Pre launch Launching Penetration of wave surface (splash zone) Transit to work space Entering work space, homing in on work task Completing work task Leaving work space Transit to surface/Moving to next work space Penetration of surface Hook-up, lifting, securing on deck

Group work no. 1 Describe physical factors to be aware of in the different phases of an AUV/UUV mission

Group work no. 1 – Student feedback Pre launch No group looked at this activity

Group work no. 1 – Student feedback Launching Launching arrangement; A-Frame, crane etc Readiness for operation, eg. various equipment on board All openings on the hull surface must be closed (watertightness)

Group work no. 1 – Student feedback Penetration of splash zone Impact loads Hydro-elasticity Relative motion; phase, amplitude, frequency Change of parametres from air to water (buoyancy, eigenfrequency, etc.) Wire tensions

Group work no. 1 – Student feedback Transit to work space Navigation/control system (current/flow/(diving)), DP Buoyancy during transit ( different layers of salinity in the sea) Resistance/propulsion/endurance/power supply Material/hullform ( the vehicle has to withstand high external pressure)

Group work no. 1 – Student feedback Entering work space, homing in on work task No group looked at this activity

Group work no. 1 – Student feedback Completing work task Battery capacity Check if mission is completed Check the current conditions Safe manoeuvring to avoid collisions, damage of propellers Interaction between thrusters

Group work no. 1 – Student feedback Leaving work space No group looked at this activity

Group work no. 1 – Student feedback Transit to surface/Moving to next work place Changing buoyancy (pressure/gravity) Resistance forces (transit between workfields) Current forces Wave influence near surface

Group work no. 1 – Student feedback Penetration of surface Movements induced by: Waves Current (viscous forces) Buoyancy/gravity Reaching the surface -> change of: Wetted surface (viscous) Buoyancy (volume) According to the sea state, we can have very unstable system

Group work no. 1 – Student feedback Hook-up, lifting, securing on deck Sea state; ship motion, AUV motion Effect of wind in the crane Centre of gravity of AUV Lifting Splash zone, wind, safety distance Securing on deck Safe lie bed

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Section of FREESUB AUV database 4 SEAGLIDER Applied Physics Lab - Univ of Wash. JP 1000 24 Li Ion 4000 0.3 9 EAVE III AUSI USA 10 SAUV (Solar Powered AUV) AUSI & IMTP USA & RU Ni-Cd 2/hr 2

R&D program on Underwater navigation Develop navigation systems to be used for missions with long period of submerged vehicle Error robust systems, optimal use of working sensors Develop mathematical models and algoritms for new sensors with extreme precision In water testing of new sensors and mathematical models Project is based on experience and solutions used for the HUGIN family of vechicles

ROV overview ROV: Remotely Operated Vehicle with umbilical connection to a mother vessel. Umbilical are used for power transfer to ROV and for communication between ROV and pilot

ROV types/classes Observation ROVs Work ROVs Tether management system Advanced intervention tasks High work construction capacity Optimisation of power efficiency Tether management system

ROV operational phases Pre launch Launching Penetration of wave surface (splash zone) Transit to work space Entering work space, homing in on work task Completing work task Leaving work space Transit to surface/Moving to next work space Penetration of surface Hook-up, lifting, securing on deck

ROV operational goals Visual observation Inspection of underwater structures Observation of ongoing work tasks on subsea structures Different types of mechanical inspection Non destructive testing Mechanical work

Example of ROV operation See Oceaneering presentation

Challanges for future ROV operations Better vizualisation Better planning Better reporting systems More training Simulation to verify access to work sites Central control of operations

Necessary improvements for advanced ROV operations 3D navigational tools 3D based planning tool Digital, visual ”online” reporting Realistic simulator training Access verification using simulator during the engineering planning of the operation Central placed special control room

Phases of ROV operation Pre launch Launching Penetration of wave surface (splash zone) Transit to work space Entering work space, homing in on work task Completing work task Leaving work space Transit to surface/Moving to next work space Penetration of surface Hook-up, lifting, securing on deck

Oceaneering – Ongoing work MIMIC Modular Integrated Man-machine Interaction and Control VSIS Virtual Subsea Intervention Solution (Switch to Oceaneering presentation, slides 16 ->)

Buzz groups question 3 What are the critical activities for each of the phases in an ROV operation? One phase per buzz group

Buzz group Q3 answer

TMR4225 Marine Operations, 2004.01.16 Sum up the 3 most important learning outcomes of todays lecture Have your expectations been fulfilled? If not, why not? Feedback is written up in a separate Word document