Fluid structure interaction in piston diaphragm pumps

Piston diaphragm pumps are used world-wide to transport abrasive and/or aggressive slurries against high discharge pressures in the mining, mineral processing and power industries. Limitation of excessive deformation of the diaphragm is of utmost importance for eliminating fatigue failures of the diaphragm and thereby obtaining a high reliability of the piston diaphragm pump. The deformation shape of the diaphragm is the result of a complex 2-way Fluid Structure Interaction (FSI) mechanism within the pump chamber between the propelling fluid, the diaphragm and the pumped slurry. The understanding of this FSI mechanism has improved in the last decades but is still limited. Load and deformation analysis of the diaphragm is currently based quasi-static assumptions. This is however an over-simplification, especially for the larger piston diaphragm pumps used in the mining and mineral processing industries. In these applications, fluid momentum loading by both convective as well as unsteady fluid acceleration become important to consider. For improved analysis of the diaphragm deformation a numerical model is required. The objective of this study is therefore:

Development of an experimentally validated numerical Fluid-Structure-Interaction model for the prediction of, operating condition induced, diaphragm deformation in piston diaphragm pumps