中空電極部のアークプラズマ流の分光温度計測

Abstract

Arc heated wind tunnel facilities were produced high enthalpy flows, which are used for purposes to investigate as testing thermal protection technology of reentry flow into the earth or other planets. Huels type DC-arc heater is designed and constructed in Aichi Institute of Technology. The emission spectra in an arc heated flow are obtained to estimate the vibrational and rotational temperatures from Boltzmann plot method. The B^2Σ_u^+-X^2Σ_g^+ transition of AΔν=0 of the N_2^+ molecule, is referred in the UV region of 383 to 392 nm as the N_2^+ 1st negative band system(N_2^+ 1-), and the C^3Π_u-C^3Π_g transition of Δν=1 of the N_2 molecule, is referred in the UV region of 309 to 316 nm of the N_2 2nd positive band system(N_22+). Average vibrational temperatures T_ν are determined to be 4300～4700K from N_2^+ 1- and 2800～3100K from N_22+ for air. The rotational temperature in R-branch are obtained from (0, 0) and (1, 1) transition of Δν=0 for the N_2^+ 1-. The average rotational temperature T_r of N_2^+ 1- is obtained to be 3500～3800K from 2<J'<26 of the rotational quantum number.