A novel linear model of vibration for industrial mixing equipment is introduced. The model includes contributions to the mass, damping and stiffness coefficients from fluid forces on the impeller, in addition to structural elements. The fluid added mass, damping and stiffness model coefficients were derived from Large Eddy Simulation (LES) of turbulent flow in a mixer with a pitched blade impeller undergoing small prescribed circular orbits. Model predictions of impeller whirl instability were compared to experimental data with good agreement. The simplicity and speed of the new model make it of use for on-line diagnostics and operational planning.
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