Onsager’s reciprocal relations in electrolyte solutions: I. Sedimentation and electroacoustics

In the framework of irreversible thermodynamics, we show that the sedimentation current in electrolyte solutions is mathematically equivalent to the low frequency limit of the ionic vibration current, appearing in the presence of an acoustic wave. This non-trivial result is obtained thanks to a careful choice of the reference frame used to...

Local Scour: Damping of turbulence parameters in relaxation zone

The general purpose of this research project is to model mathematically the scour-hole downstream of a structure (2-D). The model has to simulate the development of the scour as a function of time. Basically two models are necessary namely a flow model and a morphological model. The latter has to describe the bed- and suspended load and the...

The effect of the cell-Reynolds number in the numerical solution of the convection-diffusion equation

Internal memo. In the numerical solution of convection-diffusion equations a difficulty is commonly met in the occurrence of "standing waves" or spatial oscillations of a numerical origin. This has given rise to a considerable number of methods designed to avoid oscillations, often by means of upstream differencing or a similar approach in...

A Simple Diffusion-Controled Model of Mixing Across a Stable Density Interface

Mixing across a stable density interface caused by a shear stress externally acting on a two-layer fluid initially at rest is modelled using the turbulent-diffusion concept. The influence of a (relatively weak) longitudinal pressure gradient is also considered. The central point of view developed is that the mixed layer can be only weakly...

A model of turbulent diffusion

Mathematical description of turbulent diffusion with constant mean velocity gradient.

Jet diffusion in stagnant ambient fluid

Submarine outfall disposal of domestic and industrial sewage is a method of disposal of steadily growing importance. The flow from an ocean outfall is essentially that of a submerged horizontal or vertical jet. Thus a study of the hydrodynamics of such jets is needed to evaluate the dilution of the sewage flow. A study of this kind is presented...

Mean value and correlation problems connected with the motion of small particles suspended in a turbulent fluid

A theoretical treatment of diffusion as function of turbulence, by working out the dispersion of small particles in turbulent fluid. The method of Kolmogoroff is used to decribe the movement in a statistical ways