Draft Statement of Work.pdf

Statement of Work / Performance Work Statement United States Naval Academy

Naval Academy Hydromechanics Laboratory

380 FT Towing Tank Wavemaker

1. Background. The Naval Academy Hydromechanics Laboratory (NAHL) features a 380 FT towing tank with the following dimensions: 380 FT (116.0 m) length, 26 FT (7.9 m) width, and 16 FT (4.9 m) water depth. Typically, the towing tank supports a wide variety of activities for the United States Naval Academy (USNA) focusing primarily on Naval Architecture and Ocean Engineering (NAOE) courses/electives and diverse student/faculty research. The current dual-flap wavemaker has a servo-hydraulic control with a dry back and is nearly 50 years old. The vendor of the wavemaker no longer fabricates, installs, or supports wavemaking systems and replacement parts are difficult to get. Frequent system faults occur which negatively affect the educational and research missions of the NAHL. The existing wavemaker is mounted to a foundation approximately 56.5 IN (1.435 m) above the base level of the tank.

2. Objectives. The primary aim of this procurement effort is to purchase a new wavemaker

(including wavemaking software) for the NAHL 380 FT Towing Tank. Successful installation/operation of a new wavemaker in the 380 FT Towing Tank will improve NAHL operations in the 380 FT Towing Tank and be used to mitigate the technical risk of future investment/procurement activities.

3. Scope. This procurement is exclusively limited to the purchase/installation of one wavemaker (and associated operating software) for the NAHL 380 FT Towing Tank. Work required includes removal of the existing wave making system, installation of a new, state of the art system including training, technical data, essential spare parts, and details related to warranty, software, and maintenance. Required structural and foundation work must be planned and supported.

4. Requirements. The following requirements relate to this procurement effort:

a. Wavemaker Drive System:

i. The wavemaker shall be designed, constructed, and installed by the contractor.

The mechanical connection shall be corrosion resistant and connected to the concrete shelf structure. Final alignment of the wavemaker and associated structure is the responsibility of the vendor.

ii. The wavemaker shall be designed to fit the full width of the tank [26 FT (7.9 m)] and operate at the existing facility water depth [16 FT (4.9 m)]

iii. The wavemaker drive system shall be engineered and designed to function without degradation for the entire life of the system as specified. Periodic maintenance is acceptable. Materials used as part of the wavemaker system shall be capable of withstanding constant immersion and extended periods of both near constant use and idleness.

iv. Any routine maintenance items shall be capable of being performed without having to enter the water.

v. The drive system shall be protected against over voltage, over current, thermal, and short circuits.

vi. If the wavemaker drive system involves hydraulics, there shall be an appropriate containment system to contain any leaks caused from a malfunction or from regular maintenance. Hydraulic fluid from the drive system shall not make contact with the water in the towing tank.

vii. The wavemaker shall have a control to interface with a personal computer which has the wavemaker software installed.

viii. The wavemaker shall be controllable from both a control booth located near the waveboard (a local operating station/console placed on the existing observation deck) and the control room near the beach of the tank (the wavemaker shall be able to be remotely controlled).

ix. The contractor shall perform validation testing and tuning of the wavemaker performance.

b. Electrical System:

i. All drive power and feedback sensor interconnecting wiring shall be insulated and protected against physical damage per local building codes and the National Electric Code.

ii. The wavemaker shall use the existing power distribution system in the 380 FT Towing Tank limited to 120V, 208V, or 480V 3-Phase connections.

iii. Electrical connectors within the towing tank walls shall be IP69 rated. Those and other connectors shall be corrosion and humidity resistant and engineered to function the entire life of the system.

iv. Cable wire trays shall be formed of non-corrosive and non-conducting materials. Cable and wire trays shall be either positioned where they will not be stepped upon or sufficiently strong to resist stepping.

c. Safety:

i. There shall be a visual motion signal which will energize five (5) seconds prior to wavemaker operation.

ii. There shall be the ability to locally disable a drive such that it can not be remotely operated. There shall be emergency stops located at the user interface locations near the waveboard and in the Control Room.

iii. There shall be limit switches on travel with appropriate system shutdown capability via an e-stop circuit that disconnects power from all drives.

iv. Failsafe modes shall be used at all times for the system design.

d. USNA desires a 20-year service life before major refurbishment with the option for a Service Life Extension refresh. The contractor shall account for stress amplitude and frequency, material ductility, surface finish, heat treatment, temperature, corrosion, galvanic action, and stress concentration as appropriate.

The wavemaker is in active use for 360 hours during a typical year.

e. Reliability: Required maintenance downtime should be minimized and not exceed five (5) days per year with a possible long-term maintenance period of not to exceed 15 days every three (3) years.

f. Maintenance:

i. The contractor shall provide a manual with planned maintenance including frequency, required training or skill level, required special tools, and detailed procedures for all tasks. The manual shall contain a troubleshooting guide listing symptoms and likely causes and remedies.

ii. The contractor shall train USNA/NAHL staff on wavemaker and wavemaking software operations.

iii. The wavemaker shall not require more than 40 labor hours per year for scheduled inspection, maintenance and routine minor repairs and/or wearing part replacement.

g. Warranty: The contractor shall provide a warranty for a period of at least one year from the date of acceptance. All scheduled on-site inspections and maintenance shall be included.

h. Performance Specifications: The wavemaker shall be capable of generating consistent/repeatable and finely/highly-controlled sea-states of varying amplitude and wave period. The wavemaker shall have wave absorption and wave height control software and wave tank gauges to allow wave height control or tank calming between test set ups.

i. The wavemaker shall produce both regular long-crested and irregular long-crested wave making envelopes as shown in Figure 1 below.

Figure 1: USNA 380’ Tank Wavemaker Regular Wave Design Envelope

ii. The wavemaker shall be capable of creating regular waves of lengths (𝜆) from two (2) FT (0.60 m) to 57 FT (17.4 m). All wave lengths shall have a minimum wave height of 𝜆/150 or 1.0 IN (2.54 cm), whichever is greater. The wavemaker shall be capable of generating regular waves with a steepness of 𝜆/10 to a maximum height of 3 FT.

iii. Regular waves shall not vary in amplitude from the programmed value more than ±5 percent.

iv. The wavemaker shall be capable of creating irregular waves that are defined by the user in terms of a given energy or amplitude spectrum (e.g., ITTC spectral form) or a linear superposition of discrete sinusoidal regular waves.

v. The frequency range for regular or irregular waves shall be at least from 0.3 Hz to 1.6 Hz.

vi. Wavemaking Accuracy - Regular Waves:

1. A maximum percentage spatial variability in peak wave height of 5% from average peak wave height simultaneously measured anywhere along a wave crest anywhere in the wave creation envelope with wave steepness 1/30 or less. Measurements to be taken after start up-transient and prior to the first wave reflection.

2. A maximum percentage of harmonic distortion of 5% for regular waves of wave steepness ratio less than 1/40. Measurements to be taken after start-up transient and prior to the first wave reflection.

3. A maximum RMS amplitude error, expressed as a percentage of the commanded wave height, versus time of 5% for regular waves of wave steepness ratio less than 1/60. Measurements to be taken after start-up transient and prior to the first wave reflection.

4. A maximum percentage difference of 2% from average peak amplitude measured at any fixed location from the wave boards for ten wave bursts into a calm basin at frequencies of 0.4, 0.7, and 1.4 Hz and a wave steepness of 1/40.

vii. Wavemaking Accuracy - Irregular Waves:

1. A maximum percentage spatial variability of 5% in RMS wave height measured anywhere along the crests.

2. A maximum percentage difference of 5% between the theoretical and measured spectral density for a given significant wave height and modal period.

3. A maximum percentage difference of 2% from the average significant wave height measured anywhere along a fixed distance from the wave boards for a five minute wave burst into a calm basin at modal frequencies of 0.4 and

0.7 Hz.

viii. Software: The software shall consist of two general categories: wave synthesis and machine control. The contractor shall provide software training/training materials.

1. Wave synthesis software shall comprise the operator interface, programming wave board motion command files, sea spectra selections, predictive simulation of the tank water surface, links to the data acquisition system, carriage controls, etc.

2. Wave synthesis software shall be presented in a graphical user interface, including help features to explain the significance of each entering argument. All documentation shall be in English and grammatically correct in the United States of America.

3. The user shall be able to select either metric or English units.

4. The wave synthesis software shall enable the operator to select any sea spectra, facilitate entering the various parameters, and link the wavemaker start up and phasing in time to experimental events such as model acceleration and release, commencement of data acquisition, carriage motion, dye release, wind generation, etc. The link between wavemaker and events can be accomplished in the form of the ability to synchronize with or trigger other instrumentation (such as providing a 5 volt pulse to a BNC output upon the start of a wave run, for example).The software will enable the operator to view, save, print, and modify the wavemaker drive command files.

5. The repeat length for all spectra shall be user set with no pre-programmed limitations.

6. The software shall enable the operator to predict the wave field at any point in the tank in both the time and frequency domains.

7. The software shall enable the operator to refine commanded spectra to reduce the difference between the commanded and measured spectra, ie. a gain setting to lower wave amplitude.

ix. Machine control software operates to control the individual waveboard servo drives, accepting motion trajectory files, start and stop commands, and timing from the wave synthesis software. The machine control software performs diagnostics, condition monitoring, and facilities adjusting gain settings and troubleshooting.

1. The machine control software shall be configured to accept wave board motion data files, start, stop, and other commands from the wave synthesis software described above. It shall have the capability to perform condition monitoring of each driven element, including motors, servo drives, including but not limited to warnings, cautions, overload, fault current, feedback sensor failure, out of limit, over speed, etc. All condition and status data shall be available to customer maintenance personnel. All warnings and failures shall be available to customer maintenance personnel. All warnings and failures shall be available to operators. Error messaging for all common malfunctions including at a minimum high motor temperature caution, maximum allowable motor temperature exceeded, motor over torque, change in motor impedance, motor speed sensor failure, motor temp sensor failure, when the motor driver is limiting power to any motor, drive position or velocity error exceeding a threshold the value of which is set by the contractor but adjustable by the customer, etc.

2. A file of default settings for gains, limits, offsets, scaling values, etc. shall be provided following acceptance testing. The waveboard drives shall include features to adjust gains for feed forward PID, current limits, offsets, scaling values, constants for feedback and motor constants, and speed limits via

PC interface. A feature that enables saving a set of settings shall be included.

3. The system shall be equipped with a logging feature that records time periods of inactivity, standby, and in use.

i. Sea Spectra: At a minimum, the wave generator software graphical user interface shall be equipped to enable an operator to input parameters for regular and irregular waves as specified below.

1. Regular waves - height, wave length, period, frequency, wave number

a. The regular wave options shall include cyclic (square, triangle, or sine shapes), random, displacement (entered time history record), Airy, Cnoid, and Stokes.

2. Pierson-Moskowitz spectrum as defined by significant wave height, modal period, or modal frequency

Pierson-Moskowitz spectrum of the form S(ω) = (A/ω5)exp(B/ω4) where A = -0.0081 (g2)

B = -0.032 (g/Hs)2 g = acceleration of gravity Hs = significant wave height = 0.004057 g Tm

3. Bretschneider spectrum as defined by significant wave height and modal period or modal frequency Bretschneider spectrum of the form S(ω) = (A/ω5) exp(B/ω4) where

A = 483.5(Hs2)/Tm4 B = -1944.5/Tm4 Tm = modal wave period Hs = significant wave height

4. Modified JONSWAP spectrum as defined by significant wave height and modal period or frequency. Default values for 𝛾 and 𝜎 shall be provided along with the ability to alter both.

Modified JONSWAP spectrum of the form S(ω) = (A/ω5)exp(B/ω4) γ ^ exp[ - (ω-ωm)2 / ( 2σ2 ωm

2 ) ] where A = 0.20495 ωm

4 Hs2

Hs = significant wave height B = -1.25 ωm γ = 3.3 σ = 0.07 for ω < ωm and 0.09 for ω < ωm ωm = modal wave frequency in rad/sec ω = wave frequency in rad/sec

5. The ability to create a “white noise” set of waves (a flat spectrum over the full range of frequencies).

6. A spectrum with a spectral density distribution of arbitrary mathematical form.

7. A spectrum with a spectral density in a tabulated format.

8. The ability to select the phase and phase distribution between individual frequency components to control wave grouping.

9. A predefined wave elevation in time at a specific location in the tank.

10. The ability to generate and apply corrections to wavemaker commands based on measured spectra at one location in the basin.

j. Documentation shall be provided that will enable diagnosing and troubleshooting issues with the system, make repairs, and source replacement parts.

5. Deliverables. The primary deliverable for this procurement effort is one, calibrated, fully-operational wavemaker system for the NAHL 380 FT Towing Tank.

The contractor shall prepare the following material for a Preliminary Design Review:

● Solid model of the system including all major components

● Engineering drawings depicting plan, profile, and end views.

● Engineering drawings of all major structural components, including anything in the load path.

● Material specifications for all wet portions.

● Material, coating, and weld specifications for all structural components.

● Detailed calculations for strength, deflection, vibrations, fatigue, reliability, thermal, hydrodynamic performance for all principal structural and drive elements, as appropriate.

● System hardware and software test plan outline

● Operator manual outline

● Wavemaker algorithm software demonstration

● Data entry screens and GUI drafted

● Predictive software demonstration

● Draft manufacturing plan indicating schedule, critical paths items, etc.

The Government will provide written comments. The Contractor will respond with a written response and plan of action to address comments before the Critical Design Review.

The contractor shall prepare the following information for the Critical Design Review:

● Complete 3-D model including all but minor parts

● Complete set of 2-D engineering drawings for all but minor components

● Revised calculations, additional calculations as warranted

● Refined wave synthesis software screens and command tree

● Draft test plan

● Draft operator manual

● Draft maintenance manual

● Address all Government comments from the Preliminary Design Review

● Final GUI formats

● Final I/O data requirements

● Final manufacturing plan for hardware, electrical and software indicating Critical Path items where necessary, priority purchases and expected completion milestones for major components.

The Government will provide written comments. The Contractor shall provide additional data, analyses, or other material to address all comments. The Government will authorize the Contractor to commence fabrication of the system hardware.

The final deliverables include the following:

a. The wavemaker design drawings and calculations.

b. The wavemaker Bill of Materials (BOM).

c. The wavemaker suggested periodic, routine, and preventative maintenance plans.

d. The wavemaker operating procedure and troubleshooting guide.

e. The wavemaking software, including training and training materials to operate the system.

f. A master hardcopy set of all electrical and mechanical engineering drawings

g. Hardcopy sets of assembly drawings depicting the principal dimensions, centers of gravity, lift and tie down points, mounting interface tolerances and dimensions.

h. Hardcopy sets of electrical schematics showing interconnectivity of all components, protection, and complete technical specification for all parts

i. Copies of digital versions of all electrical and mechanical drawings

j. Hardcopy sets of O&M and Troubleshooting manuals

k. Copies of digital versions of O&M and Troubleshooting manuals in PDF format

l. Complete procurement data for all purchased parts including contractors in house part number and the original supplier if the parts were manufactured by a third party

6. Government Contacts. The following individuals are responsible for all efforts/activities related to this procurement:

Dr. James Gose Supervisory Naval Architect (Branch Head) Naval Academy Hydromechanics Laboratory gose@usna.edu / 410-293-5102

Dr. Carolyn Judge Professor, Naval Architecture and Ocean Engineering Director, Naval Academy Hydromechanics Laboratory judge@usna.edu / 410-293-6460

Ms. Sara G. Phillips, Registered Architect, AIA Deputy for Facilities & Construction phillips@usna.edu / 410-293-1516 mailto:gose@usna.edu mailto:judge@usna.edu mailto:phillips@usna.edu

FOR REFERENCE ONLY (TO BE INCLUDED AS AN ATTACHMENT)

380 FT Towing Tank

Naval Academy Hydromechanics Laboratory

This is a reference for developing the Statement of Work (SOW) for a complete wave maker system with control and power electronics, power supply, control interface for a personal computer to replace the existing Naval Academy Hydrodynamics Laboratory (NAHL) wave maker system in 380 FT Towing Tank at the USNA.

The 380 FT Towing Tank is described as follows:

This tank is equipped with two towing carriages, a dual-flap wave maker, and a wave absorbing beach. The smaller carriage is lighter and capable of towing small models at higher speeds. The larger carriage is heavier and used to tow large models at lower speeds. Both carriages are set up with platforms to carry ten or more students, allowing close-up observation of the underway test subject/model. The center section of the tank’s beach can be lowered to allow access to a finger pier for ballasting and setting up experiments while the tank is being used for other tests. Measurements from sensors on towed models are monitored and recorded using an onboard computer. Digital measurement records and live HD video signals are transferred to the shore-based control room using wireless networks. Measurement records can be evaluated/analyzed onboard the carriage and in the control room.

This tank has been used to test a wide variety of models, including ships, submarines, planing hulls, hydrofoils, surface-effect craft, SWATHs, sailboats, offshore platforms, wave buoys, diving systems, mine arrays, pilings, etc. The tank has also been used to study wave motions and forces without the use of models.

Nominal Dimensions of the Facility:

Length = 380 FT (116.0 m) Breadth = 26 FT (7.9 m) Depth of Water = 16 FT (4.9 m) Carriage Travel = 270 FT (82.0 m)

Description of Carriage:

1. High-Speed – 11,000 LB box girder, steel wheels, round rails; maximum speed 32 FT/S (9.8 m/s).

2. Low-Speed – 22,000 LB box girder; maximum speed 25 FT/S (7.6 m/s).

Type of Drive System and Total Power:

Shore-mounted motors with twin tow cables; two motors @ 200 HP (150 kW) with 400% overload capability; controlled from shore using a computer-driven touchscreen.

Other Capabilities:

Large and small horizontal planar motion mechanisms (PMMs).

Open-water propeller testing.

Current-driven turbine testing.

Wave Generation Capability:

Regular, irregular, and transient water waves; wave frequency range of 0.25 Hz to 1.50 Hz.

Existing Wave Maker Type:

Dual-flap, servo-hydraulic control with dry back.

Beach Type and Length:

Four layers of 2 IN (5 cm) square tubes, 60 FT long (18 m); nominal slope of 1:5.

Instrumentation:

Sensors and amplifiers for measuring: force, moment, distance, angle, rotation rate and position, velocity, acceleration, inertial motion, wave elevation, water particle motion, pressure; multiple 16-bit analog-to-digital, USB-based data collection systems with sample rates of 20KHz+.

Examples of Tests Performed:

Resistance, self-propulsion, seakeeping, open-water propeller, horizontal planar motion, various tests of fixed and moored ocean structures, hydrodynamic forces on submerged bodies, foils (etc.), capsize and dynamic stability tests, flow visualization, basic ocean wave mechanics, etc.