Alternative Formulation of Laterally Averaged Hydrodynamics

Abstract

Longitudinal and vertical hydrodynamics and transport are described from the laterally averaged equations of fluid motion as shown by Blumberg in 1977, Edinger and Buchak in 1978 and 1980, and by Wang and Kravitz in 1980. The equations not only allow examining the vertical distribution of flows, but also allow examining flow properties introduced by buoyancy. Longitudinal and vertical hydrodynamics and transport apply to reservoirs and estuaries that are relatively narrow in comparison to their length and that are sufficiently deep so that stratified conditions can be established. An alternative formulation of the laterally averaged hydrodynamic and transport relationships is presented in terms of longitudinal and vertical fluxes rather than velocities and their products with various geometric averages. The formulation eliminates much of the spatial averaging of the geometry and leads to a basis for computations that more readily obtain perfect mass balances when developed to the numerical forms of the equations.