抄録
A turbulent plane jet with a chemical reaction (A+B→R) in a liquid is investigated experimentally. The instantaneous concentrations of all species (A, B, and R) are measured simultaneously by using the light absorption spectrometric method and the mass conservation law. Statistics of reactive scalar field are compared with those of nonreactive case (frozen limit) and those of instantaneous reaction case (equilibrium limit). It is ascertained that, in comparison with the frozen limit, the mean concentration of reactants A and B decrease while the mean concentration of product R increases in the downstream direction because of the chemical reaction. With regard to scalar fluctuations, it is also observed that, in the region near the exit of the jet, the r.m.s. values of species A become larger than those in the frozen limit, whereas the r.m.s. values of species B become smaller than those in the frozen limit, and vice versa in the downstream and outer region. Furthermore, the concentration correlations between species A and B have negative values. The segregation coefficients show the values between 0 and -0.3 on the jet centerline, and have minimum values at the location separated from the centerline in the cross-stream direction. The present data provide very useful and important information for modeling concentration correlation and the chemical source term in a turbulent reactive flow.
