Some properties of generalized age-distribution equations in fluid dynamics
Beckers, J.-M.; Delhez, E.; Deleersnijder, E. (2001). Some properties of generalized age-distribution equations in fluid dynamics. SIAM J. Appl. Math. 61(5): 1526-1544
In: SIAM Journal on Applied Mathematics. Society for Industrial and Applied Mathematics (SIAM): Philadelphia, Pa.. ISSN 0036-1399; e-ISSN 1095-712X, more
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Keywords |
Age Equations Physics > Mechanics > Fluid mechanics > Fluid dynamics Transport processes > Advection Transport processes > Diffusion Marine/Coastal |
Abstract |
The concept of age in fluid dynamics is analyzed in the case of a tracer advection- diffusion equation. From the general solution in a uniform velocity field, it is shown that unexpected symmetry properties arise for the age field. In particular, for a point release, the age field is isotropic, regardless of the direction of the flow and the value of the diffusion coefficient. The analysis is then extended to situations with time-varying currents, where the symmetry can be broken under some circumstances. Finally, we show a method by which a time-dependent problem can be used to assess a stationary concentration distribution function, providing details about the propagation of younger and older material at a given location. |
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