Prediction of shock-layer ultraviolet radiation for hypersonic vehicles in near space

Niu, Qinglin; Zhang, He; Dong, Shikui

doi:10.1016/j.cja.2016.04.021

Cited by 16 publications

(6 citation statements)

References 20 publications

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“…For hypersonic flows above 40 km, the time scale of the chemical and the internal energy exchange processes is comparable with the characteristic time of flows [5]. The internal energy For the air around the OTV, the flows are hypersonic and go through chemical nonequilibrium and thermal nonequilibrium conditions due to the drastic environmental changes.…”

Section: Description Of Cfd Solvermentioning

confidence: 99%

Section: Description Of Cfd Solvermentioning

confidence: 99%

“…The internal energy exchange should be described through multiple temperatures. Recently, our research group carried out a series of simulations of hypersonic reacting flows using an in-house code [5,6]. In the code, a two-temperature CFD solver is available for predictions of thermal-chemical nonequilibrium flows.…”

Section: Description Of Cfd Solvermentioning

confidence: 99%

“…Thus, the LOS method was applied in this study due to a compromise between computational cost and accuracy. The LOS method was introduced in our previous studies [5,38]. LOS starts with a surface element, and the surface emission I λ,sur can be treated as the initial value of the RTE.…”

Section: Optical Radiative Properties Of High-temperature Surfacesmentioning

confidence: 99%

“…During the entry phase, the air around the aircraft undergoes strong compression along with high frictional forces acting on the aircraft body, resulting in hot reaction air flows. In the high-temperature flow field, many chemical reactions occur including dissociation, ionization, and recombination [5,6]. Under these conditions, air components, consisting of atoms, ions, and molecules, radiate strong optical radiation [7].…”

Section: Introductionmentioning

confidence: 99%

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Infrared Optical Observability of an Earth Entry Orbital Test Vehicle Using Ground-Based Remote Sensors

et al. 2019

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Optical design parameters for a ground-based infrared sensor rely strongly on the target’s optical radiation properties. Infrared (IR) optical observability and imaging simulations of an Earth entry vehicle were evaluated using a comprehensive numerical model. Based on a ground-based IR detection system, this model considered many physical mechanisms including thermochemical nonequilibrium reacting flow, radiative properties, optical propagation, detection range, atmospheric transmittance, and imaging processes. An orbital test vehicle (OTV) was selected as the research object for analysis of its observability using a ground-based infrared system. IR radiance contours, maximum detecting range (MDR), and thermal infrared (TIR) pixel arrangement were modeled. The results show that the distribution of IR radiance is strongly dependent on the angle of observation and the spectral band. Several special phenomena, including a strong receiving region (SRR), a characteristic attitude, a blind zone, and an equivalent zone, are all found in the varying altitude MDR distributions of mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) irradiances. In addition, the possible increase in detectivity can greatly improve the MDR at high altitudes, especially for the backward and forward views. The difference in the peak radiance of the LWIR images is within one order of magnitude, but the difference in that of the MWIR images varies greatly. Analyses and results indicate that this model can provide guidance in the design of remote ground-based detection systems.

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Section: Description Of Cfd Solvermentioning

confidence: 99%

Section: Description Of Cfd Solvermentioning

confidence: 99%

Section: Description Of Cfd Solvermentioning

confidence: 99%

Section: Optical Radiative Properties Of High-temperature Surfacesmentioning

confidence: 99%