ELCOM Methods

Numerical Techniques in CWR ELCOM

Ben R. Hodges

Abstract:

A description of a 3D estuary and lake computer model (ELCOM) is provided. The model solves the unsteady Reynolds-averaged Navier-Stokes (RANS) equations using a semi-implicit method with quadratic Euler-Lagrange discretization of momentum advection and a conservative ULTIMATE QUICKEST approach for scalar transport. A one-dimensional mixed-layer model is extend to 3D for turbulence closure of vertical Reynolds stress terms.

This technical report is the fundamental description of the ELCOM code. The paper Hodges et al (2000), published in L&O <here>, provides the peer-reviewed description of the turbulence model (which is the really new stuff). I originally included much of this technical report in the L&O paper, but the editors made me drop it as the paper was too long. I had intended to try to write a journal paper on the remainder of the method, but never got around to it. There are some fairly unique things in the ELCOM algorithms, but the basic method is founded on the TRIM approach of Casulli and Cheng (1992).