Sizing Power Generation and Fuel Sizing Power Generation and Fuel Capacity of the All-Electric Warship Warship May 22, 2007 IEEE Electric Ship Technologies Symposium, A li Arlington, Virginia t Vi i i CAPT Norbert Doerry Deputy Director, Future Concepts and Surface Ship Design p y , p p g Naval Sea Systems Command SEA 05DB (202) 781-2520 norbert.doerry@navy.mil y@ y
All-Electric Warship Vision Organic Surveillance Drone High Altitude Beam Power to Aircraft B P t Ai ft Minimal Handling - No Refueling High Powered Sensor Combination Sensor and Weapon Electromagnetic Gun High Powered Microwave More than 10 MJ on Target More than 10 MJ on Target High Powered Laser Megawatt Range High Energy Laser E h Enhanced Self Defense d S lf D f Precision Engagement No Collateral Damage Megawatt Class Laser Integrated Power System Integrated Power System NO ENERGETICS NO ENERGETICS Affordable Power for Weapons and Propulsion Power Dense, Fuel Efficient Propulsion All Electric Auxiliaries ABOARD SHIP! ABOARD SHIP! Reduced Signatures No Hydraulics Power Conversion Flexibility Power Conversion Flexibility No HP Gas Systems Reduced Sailor Workload May 22, 2007 Approved for Public Release 2 CAPT Doerry
Agenda • Challenges with current methods for sizing power generation and fuel tank capacity g p y • Proposed Solution – Sizing Power Generation – Sizing Fuel Tank Capacity Si i F l T k C it • Future Work May 22, 2007 Approved for Public Release 3 CAPT Doerry
Current Methods Sizing Power Generation Sizing Fuel Tank Capacity • Propulsion Power • Fuel Tanks must be large enough to achieve a given endurance to achieve a given endurance – Achieve Sustained Speed at 80% Achieve Sustained Speed at 80% range at a given endurance speed of installed Shaft HP with clean bottom and calm seas to account – 24 hour average electric load for assumed. • Weather • Weather • Sea state • Heading Relative to wind and sea direction • Fouling Fouling • Ship Service Power – Serve the Maximum margined electrical load with service life allowance without the generator of ll ith t th t f highest rating and paralleled generators loaded no more than 95%. May 22, 2007 Approved for Public Release 4 CAPT Doerry
So What’s the Problem? Sizing Power Generation Sizing Fuel Tank Capacity • Maximum margined electrical • High power mission system load may not occur when ship loads can be a significant is at maximum speed. fraction of power – On station time can become • No incentive to reduce drag at more important operationally i t t ti ll other than calm water than range at endurance conditions speed. – No credit for anti-fouling • • No incentive to reduce fuel No incentive to reduce fuel efforts ff t consumption at high speeds – No credit for hull forms that – High Speed surge to theater reduce drag in higher sea- may become operationally may become operationally states states. significant with a small fleet size. May 22, 2007 Approved for Public Release 5 CAPT Doerry
Sizing Power Generation: Impact of Sea-State • Involuntary speed p Voluntary Speed y p Reduction reduction Involuntary Speed – Depends Reduction on Direction on Direction of seas and SS 1-3 SS 4 SS 5 SS 6 SS 7 wind From PNA Probability of Sea State - Open Ocean North Atlantic • Voluntary • Voluntary 100 speed 90 80 Expect to reduction 70 Operate Time 60 Percent 50 Through – Slamming 40 SS 7 30 – Deck 20 wetness 10 0 1 2 3 4 5 6 7 8 Data From PNA SEA STATE From PNA Percentage Probability of Sea State Cumulative Probability of up to this Sea State May 22, 2007 Approved for Public Release 6 CAPT Doerry
Sizing Power Generation – Proposal • Define Mobility as a Mission System – For each operational condition based on a Concept of Operations, specify … • Mission System states y • Speed time profile • Required maximum speed and minimum tactical speed • Percentage of time at 10°F, 59°F, and 100°F – Specify a realistic sea-state to use (Upper end of SS 4?) p y ( pp ) – In calculations, include impact of hull fouling and reduced propulsion efficiency due to unsteady loading. Use the worst case heading for determining impact of Sea state • Include margins appropriate for stage of design and degree of uncertainty. • I Include a Service Life allowance for Ship Service electrical loads. l d S i Lif ll f Shi S i l i l l d • Power Generation must be capable of providing requisite Quality of Service for all operational conditions – Power Generation must be sufficient to serve all propulsion and ship service loads for all operational conditions l d f ll ti l diti – Power Generation must be capable of serving ship service loads in all operational conditions with sufficient propulsion power to achieve the minimum tactical speed without the largest Generator Set. Tie Power Generation Requirements to Operational Conditions Tie Power Generation Requirements to Operational Conditions May 22, 2007 Approved for Public Release 7 CAPT Doerry
Sizing Power Generation – Challenges • Design Tools for accurately predicting ship resistance at p g p different sea states. • Method for translating ship trial data to mobilit trial data to mobility requirements • Improved electrical load p http://www.nauticalweb.com/superyacht/530/tecnica/optimisation.htm amalgamation methods needed – Accuracy of existing load Accuracy of existing load factors questionable. May 22, 2007 Approved for Public Release 8 CAPT Doerry
Sizing Fuel Tank Capacity: Growth of Mission System Loads • Future non- mobility Mission y 35 35 Systems will likely 30 drive fuel d, MW 25 requirements requirements ectric Load 20 more than 15 propulsion 10 Ele • Endurance Range 5 and Speed may 0 no longer be no longer be Alternate Alternate DD 963 DD-963 DDG-51 Flt DDG 51 Flt DDG-1000 DDG 1000 AP Study AP Study Propulsion IIA Medium appropriate for Combatant Study sizing fuel tanks Medium Combatant May 22, 2007 Approved for Public Release 9 CAPT Doerry
Sizing Fuel Tank Capacity: High Speed Efficiency • Getting to Theater fast can be important – Reduced Fleet Size – can’t be everywhere all the time – Need for Maritime Power will not be predictable. b di t bl http://www.navatekltd.com/hyswac.html • Efficiency at high speed currently not a design factor for sizing fuel tanks f i i f l k – Ships are designed for efficiency at endurance speed, little incenti e to impro e efficienc at incentive to improve efficiency at high speed – Ship speed can be operationally limited by availability of limited by availability of replenishment ships May 22, 2007 Approved for Public Release 10 CAPT Doerry
Sizing Fuel Tanks – Proposal • Fuel Tanks should be large enough to satisfy three conditions … – Surge to Theater • Distance at maximum design speed using only 50% of fuel • Goal is to minimize dependence on replenishment ships to arrive at a theater of operations as fast as possible • Must define capability of other mission systems (self defense) – Economical Transit • Similar to traditional Endurance speed and range • Only difference is that capability of other mission systems are defined, rather than using 24 hour average load – Operational Presence • Minimum time that a ship should be capable of conducting one or Mi i ti th t hi h ld b bl f d ti more missions (such as theater ballistic missile defense) using a given speed-time profile and mission system capability • Use only 1/3 of fuel capacity Use only 1/3 of fuel capacity May 22, 2007 Approved for Public Release 11 CAPT Doerry
Future Work • Produce and implement a guidance document for specifying ship requirements. • • Formalize the methodology in standards such as the Naval Formalize the methodology in standards such as the Naval Vessel Rules and Design Data Sheets. • Develop and validate improved ship resistance tools for predicting powering requirements in various sea-states. • Develop and validate improved tools for predicting the efficiency of propulsors in various sea-states. • Develop and validate improved electric load forecasting models. • D Develop and formalize methods to correlate trials data in l d f li th d t l t t i l d t i observed sea-states to ship mobility requirements under other sea-states. • Develop and validate tools for predicting the rate of fouling and Develop and validate tools for predicting the rate of fouling and its impact on ship’s resistance for a given operational profile, antifouling features and hull cleaning strategy. • Institutionalize the use of operational profiles and operational conditions as a basis for calculating life cycle cost conditions as a basis for calculating life cycle cost. May 22, 2007 Approved for Public Release 12 CAPT Doerry
Summary • Current sizing methods for Power Generation and Fuel Capacity no longer appropriate for modern warships • Proposed new methods – Based on operationally significant requirements g – Take advantage of modern analysis tools • Much work remains to develop methodology and supporting tools and data. May 22, 2007 Approved for Public Release 13 CAPT Doerry
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