ABSTRACT
The aim of the present study is to measure the passive-scalar exchange coefficients in simplified open-channel lateral cavities and to investigate the influence of the flow and cavity parameters on this coefficient. Two methodologies proposed in the literature are applied herein: i) velocity measurement in the mixing interface and ii) dye concentration measurement in the cavity, applying a mass conservation analysis. Both estimates appear to be in fair agreement. Present results along with data from the literature reveal that: i) increasing only the cavity width does not impact the obtained exchange coefficient, ii) increasing the dimensions (while keeping the same aspect ratio) of the cavity or increasing only the water depth tends to increase this coefficient and iii) when increasing U (keeping all other parameters equal) no clear tendency is retrieved and iv) fitting trends valid for groyne fields do not apply for lateral cavity configurations.
