Joint statistics between velocity and reactive scalar in a turbulent liquid jet with a chemical reaction
T. Watanabe, Y. Sakai, K. Nagata, O. Terashima
Joint statistics between velocity and reactive scalar in a turbulent liquid jet with a chemical reaction
Physica Scripta T155 014039 2013
This article may be found at https://doi.org/10.1088/0031-8949/2013/T155/014039.
Accepted manuscript is available here.
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Abstract
Joint statistics between the velocity and the concentration of reactive species are experimentally investigated in a planar liquid jet with a second-order chemical reaction A + B → R. Reactant species A and B are premixed in a jet flow and a main flow, respectively. An optical fibre probe based on light absorption spectrometry is used to measure the instantaneous concentrations of reactive species. The stream-wise velocity and the concentrations of reactive species are simultaneously measured by combining the optical fibre probe with I-type hot-film anemometry, and we investigate the influence of the chemical reaction on correlation coefficients, joint probability density functions and cospectra of u and γi, where u is the stream-wise velocity fluctuation and γi is the concentration fluctuation of species i. The results show that the absolute value of the correlation coefficient between u and γB becomes small owing to the chemical reaction, whereas that between u and γA becomes large on the jet centreline. It is also shown that the influence of the chemical reaction on the cospectrum of u and γi in the upstream region and near the jet centreline is different from that in the downstream region and the outer edge of the flow.
日本語訳 (DeepL翻訳)
化学反応を伴う乱流液体噴流における速度と反応スカラーの結合統計量
2次化学反応A + B → Rを伴う平面液体ジェットにおいて、速度と反応種濃度の間の共同統計量を実験的に調べた。反応種AおよびBはそれぞれジェット流および主流において予混合される。光吸収分光法に基づく光ファイバープローブを用いて、反応種の瞬時濃度を測定する。光ファイバープローブとI型ホットフィルム流速計を組み合わせて流速と反応種濃度を同時に測定し、流速変動をu、反応種iの濃度変動をγiとして、相関係数、結合確率密度関数、コスペクトルへの化学反応の影響を調査した。その結果、uとγBの相関係数の絶対値は化学反応により小さくなり、一方、uとγAの相関係数はジェット中心線上で大きくなることが示された。また、化学反応がuとγiのコスペクトラムに与える影響は、上流域やジェット中心線付近と下流域や流れの外縁部では異なることが示された。
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