Computation of the WSPRO Discharge Coefficient and Effective Flow Length

This appendix documents how the effective flow length and discharge coefficient are computed for the WSPRO bridge hydraulics methodology in HEC-RAS. The effective flow length is used in the computation of friction losses from the cross section just upstream of the bridge (section 3) to the approach cross section (section 4). The coefficient of discharge is used in the expansion loss equation from sections 1 to 2. The information in this appendix was extracted directly from the Federal Highway Administrations Research Report entitled: "Bridge Waterways Analysis Model" (FHWA, 1986).