Closed Circuit Wind Tunnel

Description

{"description":" Purchase Description \nProcurement of Closed-Circuit Wind Tunnel \n\n Requirements: \n \n• This wind tunnel must be a closed circuit, as the operation of an LDV system \nrequires seed particles to be added to the air stream – in this case, a substance \ncalled Bis(2-ethylhexyl) subacute. The wind tunnel thus needs to be fitted with a \n3/8-inch Swagelok bulkhead fitting placed upstream of the test and transitional \nsections. \n \n• This wind tunnel must have a maximum operating speed of approximately 50 \nmeters per second (~9900 feet per minute). The test section walls must have 6.85 \nmillimeter (0.27-inch)-thick grooves placed at approximately 75 percent of the total \nlength of the test section as measured from the entrance in which specialized \nnozzle restriction plates can be affixed to adjust the operating range and achieve \nan air speed of 0.15 meters per second (~30 feet per minute). The typical \nturbulence intensity across this operating range must be less than 1 percent, where \nturbulence intensity is defined as the root-mean-square of velocity fluctuations \ndivided by the average test section velocity. \n \n• This wind tunnel must have a test section size of 101.6 millimeters by 101.6 \nmillimeters (~4 inches by 4 inches). Test section length can vary if the design \nmeets the following requirements: The test section must have at least two sealable \nports or fittings for the insertion of instruments of various sizes, such as Pitot-static \ntubes and hotwire anemometers. These ports or fittings must accommodate the \nfollowing instrument diameters: 4.3 mm (~0.188 in); 6.3 mm (0.25 in); 7.9 mm \n(0.313 in); 9.5 mm (0.375 in); 10.1 mm (0.4 in); 12.7 mm (0.5 in); 15.9 mm (0.625 \nin). One port must be located 49.5 mm (1.95 in) from the inlet, centered into the \ntest section; the other port should be offset from this port by 37.5 mm (1.47 in). \nAdditionally, the test section sidewalls must be made of optical-quality glass to \nminimize interference with laser propagation. The argon-ion continuous-wave laser \nused in this application has a max wavelength of 532 nanometers and 500 \nmilliwatts output power. \n \n• The wind tunnel must have a centrifugal fan design. The fan should be isolated \nfrom the rest of the tunnel system to minimize vibration. The fan must be controlled \nby a variable-frequency drive (VFD) connected to a motor of appropriate size and \npower to meet the air speed requirements listed above. The VFD must be \nimplemented such that an operator could use computer software or manual input to \ncontrol the drive and automate its function. The computer-VFD interface must not \nrely on internet or wireless connections, such as Bluetooth or WiFi. This interface \nmust be programmable via National Instruments’ LabVIEW software. \n \n• Any design submitted must be shown to meet the specific air speed and \nturbulence requirements listed above through a quantitative analysis, such as by \ncomputational fluid dynamics (CFD) simulations or other appropriate methods. \n \n\n 1.0 Delivery Requirements \n \nShipping Address: U.S. Army TMDE Activity, Attn: Michael Tyler, Building 5435, \nRedstone Arsenal, AL 35898 \n"} Solicitation Number: PANRSA26P0000033772 Type: Solicitation Base Type: Solicitation NAICS: 541715 Classification Code: 6636 Response Deadline: 2026-05-18T12:00:00-05:00 Office Address: REDSTONE ARSENAL, AL Place of Performance: Redstone Arsenal, Alabama, 35898 POC: Wanda Little, wanda.k.little.civ@army.mil, 5715889776 POC: Portia Sampson, portia.r.sampson.civ@army.mil, 520-674-8299