Abstract
A turbulent plane jet with a one-step reaction (R + B → S) in a liquid is investigated experimentally. The instantaneous concentrations of species R and S are measured simultaneously by using the light absorption spectrometric method, while the concentration of species B is determined by the conservation law. Statistics of reactive scalar field are compared with those of nonreactive scalar field. It is ascertained that, in comparison with the nonreactive case (frozen limit), the mean concentrations of reactants R and B decrease while the mean concentration of product S increases in the downstream direction because of the chemical reaction. With regard to scalar fluctuations, it is also observed that the change in the r.m.s. values of species R is small but these values become slightly small in comparison with those in the frozen limit, whereas the r.m.s. values of species B become apparently larger than those in the frozen limit. Furthermore, the segregation coefficients of species R and B in the frozen limit increase in the downstream direction because of the progress in mixing. In contrast, the segregation coefficients in the reactive case become slightly smaller than those in the frozen limit and lie between -0.14 and -0.02 in the measurement region. The present data show that the scalar covariance can not be neglected for modeling reactive flow, and provide very useful and important information for modeling concentration correlation and the chemical source term in a turbulent reactive flow.
