Closed Circuit Wind Tunnel

Solicitation / RFP / RFQ

This document is a Memorandum For Record (MFR) detailing the justification and approval for the new purchase of one (1) Closed-Circuit Wind Tunnel. This equipment will be used by U.S. Army Test, Measurement and Diagnostic Equipment Activity (USATA) engineers and technicians in conjunction with a Laser Doppler Velocimetry (LDV) system to improve air velocity measurement accuracy in wind tunnels.

• One (1) Closed-Circuit Wind Tunnel, or equivalent.

• Maximum operating speed of approximately 50 meters per second (~9900 feet per minute).

• Test section walls with 6.85 mm (0.27-inch)-thick grooves at approximately 75% of the test section length for adjustable nozzle restriction plates.

• Turbulence intensity across the operating range must be less than 1 percent.

• Test section size of 101.6 mm by 101.6 mm (~4 inches by 4 inches).

• At least two sealable ports/fittings for instrument insertion (diameters: 4.3 mm to 15.9 mm).

• One port located 49.5 mm (1.95 in) from the inlet, centered; another port offset by 37.5 mm (1.47 in).

• Test section sidewalls made of optical-quality glass.

• Centrifugal fan design, isolated from the tunnel system to minimize vibration.

• Fan controlled by a variable-frequency drive (VFD) connected to a motor.

• Computer-VFD interface programmable via National Instruments' LabVIEW software, not relying on internet or wireless connections.

• Any design must be supported by quantitative analysis (e.g., CFD simulations) demonstrating compliance with air speed and turbulence requirements.

• Action Type: New Purchase.

• Item Type: Commercial item.

• NAICS Code: 541715.

• Not explicitly detailed in this document. This MFR serves as justification and approval.

• Not specified in this document.

• Delivery Location: Building 5435 Fowler Road, Redstone Arsenal, AL 35898.

• The document references an argon-ion continuous-wave laser with a max wavelength of 532 nanometers and 500 milliwatts output power, which is used in conjunction with the wind tunnel.

Solicitation / RFP / RFQ

This document describes the U.S. Army TMDE Activity's (USATA) requirement to purchase one (1) Closed-Circuit Wind Tunnel. This wind tunnel will be used by USATA Engineers and Technicians in conjunction with a Laser Doppler Velocimetry (LDV) system as a primary standard for air velocity measurement. The objective is to allow for the measurement of lower air speeds and reduce overall laboratory measurement uncertainty. The item is to be delivered to the Army Primary Standards Laboratory (APSL) at Redstone Arsenal, AL.

• Closed Circuit Design: Must accommodate the addition of seed particles (Bis(2-ethylhexyl) subacute) for LDV system operation, requiring a 3/8-inch Swagelok bulkhead fitting upstream of the test section.

• Operating Speed: Maximum operating speed of approximately 50 meters per second (9900 feet per minute). Must be able to achieve 0.15 meters per second (30 feet per minute) using specialized nozzle restriction plates.

• Turbulence Intensity: Less than 1 percent across the operating range.

• Test Section: 101.6 mm x 101.6 mm (~4 inches x 4 inches). Must include at least two sealable ports for instrument insertion, accommodating diameters from 4.3 mm to 15.9 mm. Two specific port locations are detailed. Sidewalls must be optical-quality glass.

• Fan Design: Centrifugal fan design, isolated from the tunnel to minimize vibration. Controlled by a variable-frequency drive (VFD) connected to an appropriately sized motor.

• VFD Interface: Computer-VFD interface must be controllable via manual input or software, programmable via National Instruments' LabVIEW software. Must not rely on internet or wireless connections.

• Performance Verification: Any submitted design must demonstrate compliance with air speed and turbulence requirements through quantitative analysis (e.g., CFD simulations).

• Not specified in this document.

• Not specified in this document.

• Not specified in this document.

• The document specifies delivery to: U.S. Army TMDE Activity, Attn: Michael Tyler, Building 5435, Redstone Arsenal, AL 35898.