Water Hammer

Dominion Engineering Inc.

Water-hammer events occur when a column of moving fluid is brought to a sudden stop, generally due to a closing valve or collapsing steam pocket. The resulting change in the water’s momentum sends a pressure wave back through the piping system, potentially damaging piping, components, and pipe hangers.

When Dominion Engineering, Inc. (DEI) was contracted to analyze postulated water-hammer events at Wolf Creek Nuclear Generating Station, they turned to Ripple Design to develop a finite-element analysis (FEA) simulation of the pipe response. Faced with a very tight schedule, our engineers developed an elegant, recursive ANSYS pressure-loading macro that accounted for multiple wave splits and wave reflections in complex piping systems. The macro allowed the user to consider multiple, simultaneous water-hammer events and capture the full dynamic structural response of the system, including pipe stresses and hanger loads.