Development of a Mach 5 Nonequilibrium-Flow Wind Tunnel

作者：Nishihara M^*; Takashima K; Jiang N; Lempert W R; Adamovich I V; Rich J W; Doraiswamy S; Candler G V

来源：AIAA Journal, 2012, 50(10): 2255-2267.

DOI：10.2514/I.J051605

A small-scale Mach 5 blowdown wind tunnel has been developed to generate steady-state nonequilibrium flows. The wind tunnel uses transverse nanosecond pulse discharge, overlapped with transverse dc discharge, to load internal energy modes of N-2 and O-2 in plenum. The stable discharge is operated at high plenum pressures, at energy loadings of up to similar to 0.1 e V/molecu le in nitrogen, generating nonequilibrium nitrogen and airflows with run time of 5-10 s, translational/rotational temperature of T-0 similar to 300-400 K, and N-2 vibrational temperature of up to T-v0 similar to 2000 K. Internal energy-mode disequilibrium is controlled by injecting O-2, NO, H-2, or CO2 into the subsonic flow between the discharge and the nozzle throat. Flow over a cylinder model in a Mach 5 test section is visualized by schlieren imaging and NO planar laser-induced fluorescence imaging, using a burst-mode laser operated near 226 nm, at a pulse-repetition rate of 10-20 kHz. NO planar laser-induced fluorescence images on two single-line NO(X, v' = 0 -> A, v '' = 0) transitions are used to infer rotational temperature distributions in NO-seeded nitrogen flows in the supersonic section, with and without discharge. Single-line NO planar laser-induced fluorescence images on a NO(X, v' = 1 -> A, v '' = 1) transition are used to infer the NO vibrational temperature in a nitrogen Mach 5 flow excited by the discharge and seeded with NO. The results are compared to three-dimensional nonequilbrium flow modeling calculations, showing good agreement.

• 出版日期2012-10