Solving complicated hydraulics in an old horseshoe outlet tunnel that needs some repairs through CFD analysis.

ABSTRACT ONLY - Many dams throughout the US are currently at or beyond their original design life. Many methods are employed to upkeep and maintain these facility to extend their design life well into the future. One potential area of concern for some of these older dams is the outlet works and tunnels that pass low-medium flow releases into the downstream channel. Repeatedly repairs and upgrades are required to outlet works to mitigate degraded concrete or tunnel linings, sedimentation at the intakes or damage caused from cavitation or abrasion. The paper will focus on a facility that went through major modifications in the 90's that is again suffering from damage in the downstream chute. The problems will be highlighted, followed by the planned actions to remedy the issues. CFD analysis will be presented to show how often complex issues and be solved through simple methods.