| Description |
Turbulent mixing, the dominant mixing mechanism in turbulent pipe flow, is important for understanding contaminant dispersion in pipe ow applications. The scalar fluxes, or the covariance velocity and concentration, are important quantities in understanding the underlying turbulent mixing mechanisms because they are present in the turbulent scalar transport equation. However, the scalar flux terms give rise to a closure problem, and cannot be directly prescribed by the governing equation. Currently, limited information exists regarding the scalar fluxes. In order to contribute to the body of knowledge concerning turbulent mixing in pipe flow, scalar flux measurements were made for a centerline injection of a passive scalar. PIV and PLIF were employed to measure the velocity and concentration fields for Re = 12; 700 at x=D ? 6:5. The results of mean velocity and concentration fields compared reasonably well with theory and previously published results. Subsequently, scalar flux profi les were extracted from the planar measurements. |
