SOWtunnelmods ltbGHEE05312020.docx

DEPARTMENT OF THE NAVY

NAVAL AIR WARFARE CENTER AIRCRAFT DIVISION

STATEMENT OF WORK

for the Modification of Naval Aerodynamic Test Facility Wind Tunnel 31 May 2020

A new external balance (Government Furnished Equipment (GFE)) is being installed under the test section of the Naval Aerodynamic Test Facility (NATF) wind tunnel in room 1B45 of Building 2187, Patuxent River, MD.

The interior of the NATF test section is 4 ft. high x 4 ft. wide x 8 ft. long.

As part of this effort, the external balance will have a new larger turntable than the legacy NATF turntable. The legacy turntable is 17 inches in diameter; the new turntable will be from 36 inches to 40 inches in diameter. This will require the test section floor support structure and floor to be modified.

Statement of Work:

The CONTRACTOR shall modify the NATF wind tunnel test section to accommodate the integration of the GFE into the facility.

Item 1: Description of Work I. The CONTRACTOR shall be responsible for the following:

a. Disconnect NATF wind tunnel facility sections as necessary.

i. NAVAIR facility personnel will secure power to and any systems affected as needed.

ii. Any cables/wires/tubing that were disconnected are to be properly labelled to insure proper re-assembly.

iii. Details of NATF wiring are shown in Figs. 1a and 1b.

b. Removal of legacy balance and new balance site preparation.

i. Because the lab contains delicate instrumentation, dust must be contained as much as practicable.

ii. The new external balance is estimated to weigh approximately 1,000 lb. The new concrete floor must be level and designed to support the new balance without appreciable deflection of the floor or balance.

iii. Removal of old balance and concrete block. The CONTRACTOR shall remove the existing concrete block for the legacy external balance (2 ft X 1.5 ft X 3.33 ft) by first removing 4’X4’existing concrete floor around it. The floor is approximately 6” of rebar reinforced concrete. The legacy balance block is also composed of reinforced concrete. Details of Lab Foundation under the test section are shown in Figs. 2 through 4.

iv. Keep as much as the existing cable trough intact as practicable.

v. Fill will be added and a new rebar reinforced concrete slab will be installed to adequately support the new balance.

vi. The new concrete floor will be at existing floor grade after removal of floor tiles. This will insure that the new balance will be mounted to the floor 36” below the test section floor (wind-side surface).

vii. As much as possible, new rebar should be kept away or below the balance anchor pad locations so that anchors may be drilled without hitting the rebar.

viii. The new floor must be skimmed level.

ix. The new floor must be isolated from the existing floor around the edge:1/2" P.M.F ISO. JOINT.

c. The current 1” plywood of both side walls and ceiling will be removed and replaced with Aluminum on both side walls and ceiling of sufficient structural strength. The glass on both side walls and ceiling need to be re-installed and re-sealed using a manner consistent with the forces encountered during operation of the wind tunnel. If it possible, an option is to be priced to make the windows flush with the wall. Bore a hole to mount Pitot-static probe in the legacy location on the ceiling.

d. Re-seal sidewall doors with new gasket material.

e. Modify NATF test section to remove floor structural trusses and modify test section floor to receive a 36-inch diameter turntable.

i. The modifications must be able to with stand the loading of tunnel maximum speed of 205 ft/s. In addition to any normal loading associated with model installation preparation. E.g., multiple wind tunnel personnel working in the test section.

ii. The current 1” plywood floor will be removed and replaced with an Aluminum floor of sufficient structural strength. The thickness of the floor will be such that the GFE turntable will be of proper height and within level tolerance.

iii. A centerline reference line will be etched or scribed on the test section floor on both sides of the plates(s).

iv. The test section floor shall be level.

v. The test section floor shall utilize best wind tunnel practices to minimize step heights between other sections of the wind tunnel, within the test section, and the test section turntable. The maximum allowable step height is 0.015”.

vi. A mounting bracket for the balance pantograph system shall be attached to the underside of the forward test section. Coordination is required with the balance manufacturer to establish the hole pattern and tap size of the balance type make and model and include the manufacturer. It is expected that this bracket will be roughly 1’ wide by 8” long by 4” in height.

vii. The test section floor shall incorporate 0.063” pressure tap holes with associated stainless steel tubing. The total number of taps is approximately sixteen (16). The exact location is to be determined but notionally six (6) inches from each sidewall and spaced about one (1) foot apart. In addition, taps shall be placed along the centerline, where possible at the same lateral locations.

viii. Each sidewall and the ceiling shall incorporate 0.063” pressure tap holes with associated stainless steel tubing. The exact location is to be determined but notionally six (6) inches from each edge and spaced about one (1) foot apart. In addition, taps shall be placed along the centerline, where possible at the same lateral locations.

ix. A new support frame shall be incorporated to raise the test section to the necessary height such that the test section floor (windward side) is 36” above the facility concrete floor. The design of the test section support frame will be conducted in collaboration with the external balance manufacturer to insure full balance capability and motion.

x. If the test section doors (two) and roof need to be removed, extra care must be exercised to prevent damage to roof and door glass. The roof and each door (two) weigh approximately 700 lbs not including actuators and the motors. The limit switched will need to be removed before disassembly of the test section. The door actuators need to be disconnected from the test section door controllers. The actuators and motors need to be removed from the roof before removing the roof section.

xi. Design and manufacture a method to install CFE image struts to the test section ceiling.

1. The design shall straddle the existing ceiling window without damaging the window.

2. The design must be able to withstand the maximum tunnel speed.

3. If the design incorporates plates, forward and rearward steps to the test section ceiling shall be mitigated with bevel angles.

xii. Any bolts used shall be Grade 8.

xiii. Test Section

1. The test section consists of two doors (Sections E and F on Fig. 5) and a roof (Section G on Fig. 5) affixed to a floor (Section H on Fig. 5). The current test section floor structure is shown in Fig. 6a and 6b.

a. Sections E, and F are approximately 8’ L X 1’ H X 5’ W.

b. Section G is approximately 8’ L X 1’ H X 4’ W.

c. Section H is approximately 8’ L X 5’ H X 4.5’ W.

2. The doors and roof weigh approximately 700 lbs each.

3. The floor section weighs approximately 1,000 lbs.

f. Repair or replace damaged door Carr-Lane toggle clamp CL-150-SPC, see Figs. 7 and 8.

g. Option: Assist balance contractor

i. If the balance turntable is not flush with the test section floor (i.e., there is a step between turntable and balance because the turntable is too high), it may be required:

1. That the diffuser and/or tunnel contraction section would need to be shimmed higher (notionally ¼”).

2. And/or minor machining of the balance to turntable posts to reduce height of the posts and turntable to the alignment with the test section floor.

h. Option: Balance wind shield

1. Design, manufacture, and install a three-sided wind shield around the balance structure to shield from wind tunnel exhaust flow disrupting balance measurements. Forward/upstream side is open.

2. Shield must be transparent.

3. Shield panels must be able to be removed, ideally via fasteners, to gain access to the balance.

i. Option: Balance plenum

1. Design, manufacture, and install a structure able to maintain and with stand a plenum pressure equivalent to the test section operating at maximum speed (205 ft/s). Plenum must be transparent.

2. Plenumpanels must be able to be removed, ideally via fasteners, to gain access to the balance.

j. Option: Single fairing support system

i. A single fairing support system shall be designed, manufactured, or acquired to support a full-span model.

ii. The support system shall incorporate a pitch mechanism that shall be continuously variable from -10 to +40 degrees with accuracy of at least 0.05 deg. and a resolution of at least 0.02 deg. Physical limit switches shall prevent model motion beyond this range of angles.

iii. The magnitude of the design ranges shall be -/+ 35 lbs in drag, -/+ 20 lbs in side force, and -/+ 60 lbs in lift.

iv. The magnitude of the design ranges shall be -/+ 10 ft-lbs in rolling moment, -/+ 25 ft-lbs in pitching moment, and -/+ 10 ft-lbs in yawing moment.

v. Expected model maximum mass is 30 lbs.

vi. Strut fairing shall be provided.

1. It is not expected that the fairing will be yawed to the flow. Thus a pantograph system is not necessary.

vii. An image strut system shall be provided to allow for tare and interference corrections.

k. Model motion actuator must interface/connect with and be controlled by the balance computer.

Item 2 I. Acceptance

a. A complete acceptance plan for hardware components and factory-built components shall be provided for approval 6 weeks prior to Government Acceptance at Origin. Comment by Ghee, Terence A (Applied Aerodynamics Branch) CIV USN NAWCAD (USA): Factory acceptance? That is where I go over there and make sure the balance is acceptable for shipment over here. Any issues (hopefully none) would be caught before the balance is shipped.

II. Installation and Site Acceptance

a. The CONTRACTOR shall be responsible for supervising and/or conducting on site all activities regarding the NATF wind tunnel facility modification. The CONTRACTOR shall provide an installation and site acceptance plan two weeks prior to.Notice To Proceed (NTP).

b. The acceptance tests shall include a demonstration of facility operation equal or better than the legacy operation. I.e., the maximum facility speed, freestream turbulence, range of fan operation in blade pitch and RPM, operation of test section door, and physical sectional step heights.

c. The wind tunnel’s test section air speed, freestream turbulence, and dynamic pressure need to be certified before and after modification. The certification will be used to maintain a relationship between test section dynamic pressure, contraction nozzle pressure ring differential pressure, and the speed controller. If the certification sloes between the test section and nozzle differential pressure, calculated before and after the move, vary by more than 1% the reason for the change needs to be investigated and solved. Similarly, if freestream turbulence varies by more than a percent difference from the pre-modification measurement of 5%, the reason for the change needs to be investigated and solved.

d. The maximum speed shall not vary by more than 1 ft/s before and after modification without the reason for the change investigated and solved.

e. The test section certification will be conducted at five locations as depicted in Fig. 9. Probe locations 4 and 5 will remain fixed while the center probe will be moved manually to locations 1, 2, and 3. The data from probe locations 4 and 5 will be used to correlate the data from the other locations. The test section will be certified from 25 ft/s to 200 ft/s in increments of 25 ft/s. Certification data will also be taken at a minimum speed of 10 ft/s and the maximum speed that has traditionally been 205 ft/s. The Pitot-static probes will be moved manually through the wind tunnel false wall.

f. Turbulence intensity will be measured at 50 kHz sampling rate for 1 s at the test section center position from 25 ft/s to 200 ft/s in increments of 25 ft/s.

g. The alignment of the wind tunnel will be based on the test section floor table. The test section shall be level longitudinally and laterally within 0.001 in/ft. The other tunnel sections shall be aligned based on perpendicular and horizontal planes from the test section floor. The air intake and exhaust planes shall be within 0.005 in/ft from perpendicular reference plane (lateral and vertical axis) of the test section floor. The center of each section must be aligned with either a piano wire or other agreed upon method to the test section floor and centered on the tunnel centerline. There shall be no discontinuities between test section, bell mouth nozzle (two sections), first diffuser. Discontinuities will be measured by NAVAIR personnel before and after modification. Discontinuities after re-assembly which are larger than before modification/disassembly shall be deemed unacceptable.

h. Limit switches shall be re-set and re-aligned after re-assembly to insure satisfactory operation.

i. All systems (e.g., wind tunnel doors, speed control instrumentation) are to operate the same as before facility modification.

III. Documentation

a. Any electronic copy of installation, stress/load report, and assembly drawings of the modification shall be provided. Drawings must include all mechanical, electrical, and system layouts.

IV. Warranty

a. CONTRACTOR shall warrant the performance to the stated requirements for a minimum of one year from the date of final acceptance at the NAVAIR’s site. Warranty shall cover all costs of repair including, but not limited to, materials, labor, travel, etc. to repair any manufacturer’s defects as required and allow NAVAIR acceptance of such repairs.

b. Any damage caused to the facility or associated instruments and equipment by the CONTRACTOR through accident or negligence shall be repaired at no cost to the Government.

V. System Cost

a. Note: Please include an itemized cost breakdown (including optional items); including any and all additional costs

Fig. 1a: Conduit Layout

Fig. 1b: Conduit Layout

Fig. 2: Foundation Plan

Fig. 3: Pedestal Details

Fig. 4: Floor Details

Fig. 5: Schematic of NATF wind tunnel sections.

Fig. 6a: Test Section Floor Details

Fig. 6b: Test Section Floor Details

Fig. 7: Carr-Lane CL-150-SPC Toggle Clamp and Angle Mount.

Damaged due to overload. Part deformed.

Fig. 8: Damaged Carr-Lane CL-150-SPC Toggle Clamp and Angle Mount.

Fig. 9: Test Section Cross-Section Probe Location image2.jpeg image3.jpeg image4.jpeg image5.jpeg image6.jpeg image7.jpeg image8.jpeg image9.jpeg image10.jpeg image11.jpeg image1.jpeg image12.wmf