Dispersion and persistence of tracer in river flow measurements

The development of an aquatic spill model for the White Oak Creek watershed, Oak Ridge National Laboratory, Oak Ridge, Tennessee

“…The correlation developed by Hull et al (1958Hull et al ( ,1962) is shown in Fig. 4.1 as well as the measured values on which it is based.…”

“…Velocity differences are caused by the shear imparted to the fluid by the streambed and its associated roughness as well as superimposed random motions of the fluid that are turbulent. Hull (1962) developed an empirical correlation for the longitudinal dispersion coefficient 0, based on experimental measurements made in the South Fork of the American River and results obtained from earlier tests (Hull and Macomber 1958). The American River runs through a deep, rocky northern California gorge in which water is churned by rapids located several hundreds of meters (yards) apart.…”

“…(4.1) could be adjusted to better match actual dispersivities after experimental results become available for the Clinch River below Melton Hill Dam and the mouth of WOC. Hull (1962) reported the following correlation for the entrance length L, (ft) required for complete mixing from a side discharge (as opposed to a discharge entering at mid-stream):…”

APPLICATION OF A RESIDENCE TIME MODEL TO DILUTION GAUGING, WITH PARTICULAR REFERENCE TO THE PROBLEM OF CHANGING DISCHARGE / L'application d'un modèle du temps de résidence au jaugeage par dilution, en signalant particulièrement le problème de l'écoulement changeant

“…It is seen that the error 5(r) is effectively zero after four times the mean residence time for the first distribution, and 1.5 times the mean residence time for the second case. The curves obtained by Hull (1962) suggest residence time distributions falling between the two examples. Figure 5 and Table 1 show the results of the calculation of e(t), the error due to changing discharge, using the hydrograph given by equation (11) and the gamma residence time distribution E(9) = aj 2 0exp(-co0)…”

“…In mixing length studies transverse and vertical dispersion is important, whereas longitudinal dispersion is dominant in the problem of changing discharge. Hull (1962) is one of many authors who have used the theory of longitudinal dispersion in the analysis of tracer experiments. After an instantaneous injection of a radiotracer, gold-198, in a turbulent natural stream, he obtained curves of concentration against time at a series of downstream stations (Fig.…”