Spectral Radiant Intensity Calculation of Air in Shock Tube
Radiative heat may be greater than convective heat when flying at the velocity above 10 km/s. It is critical to precisely predict radiative heat for thermal protection system design. High-enthalpy flowfield solving and gas species’ radiant coefficient calculation are two main contents in computing radiation heat. A series of tests to obtain quantitative emission spectral radiation of air at high velocity have been conducted in a detonation-driven shock tube. Based on optical calibration and measurement, volumetric spectral radiant intensities of N2 and air have been acquired in the spectrum range of 310–380 nm and in the velocity range of 5.5–8 km/s. Unsteady non-equilibrium Navier-Stokes equations were numerically solved for temperature and gas concentration in the shock tube under test conditions. A narrowband model was used to calculate the gas spectral intensity at the specific position behind the shock corresponding to test time delay. The comparison between the computational results and the test measurement shows that the predictions of the flowfield parameters and the gas spectral radiation intensities are accurate and reliable.
The authors gratefully acknowledge the support by the National Natural Science Foundation of China (Grant No.: 11402251).
- 3.D. Hash et al., FIRE II calculations for hypersonic nonequilibrium aerothermodynamics code verification: DPLR, LAURA, and US3D, in 45th AIAA Aerospace Sciences Meeting and Exhibit, p. 605 (2007)Google Scholar
- 4.D.L. Cauchon, Radiative Heating Results from the FIRE II Flight Experiment at a Reentry Velocity of 11.4 Kilometers per Second. NASA TM X-1402 (1967)Google Scholar
- 8.A.M. Brandis, B.A. Cruden, Benchmark EAST experiments for earth re-entry, in 55th AIAA Aerospace Sciences Meeting, p. 1145 (2017)Google Scholar
- 9.A.M. Brandis et al., Non-equilibrium radiation for earth entry, in 46th AIAA Thermophysics Conference, p. 3690 (2016)Google Scholar
- 11.H. Takayanagi, K. Fujita, Absolute radiation measurements behind strong shock wave in carbon dioxide flow for mars aerocapture missions, in 43rd AIAA Thermophysics Conference, p. 2744 (2012)Google Scholar
- 12.X. Lin et al., Measurements of non-equilibrium and equilibrium temperature behind a strong shock wave in simulated Martian atmosphere. Acta Mech. Sinica 28, 5 (2012)Google Scholar
- 13.C.O. Johnston, Nonequilibrium Shock-Layer Radiative Heating for Earth and Titan Entry, Ph.D. Thesis, Virginia Polytechnic Institute and State University, Blacksburg, 2006Google Scholar
- 14.R.N. Gupta et al., A Review of Reaction Rates and Thermodynamic and Transport Properties for an 11-Species Air Model for Chemical and Thermal Nonequilibrium Calculations to 30000 K. NASA STI/Recon Technical Report N, 90, 27064 (1990)Google Scholar