Secondary flow correction for depth-averaged flow calculations

A secondary flow correction has been added to the depth-averaged computer program, RMA2. The program solves a transport equation for streamwise vorticity and converts it to accelerations due to secondary currents. The inclusion of these additional accelerations results in improved predictions of depth-averaged velocity. In particular, their effect is to reduce depth-averaged velocities on the inside of curves and increase them on the outside of curves. The bendway correction has been tested on experimental data from the Riprap Test Facility at the U.S. Army Engineer Waterways Experiment Station.