A FEA simulation study on impeller failures considering various materials

This work focuses on various FEA simulations conducted to study the behaviour of six impeller materials in order to predict their failures. It is through analysing the various stresses, strains and safety factor during its operation. Two static structural simulations were performed to (i) benchmark common impeller materials namely FV520B, 316 L and 17-4 precipitation hardened stainless steels, and (ii) to investigate three proposed alternative materials namely duplex stainless-steel, nickel aluminium bronze (NAB) and cast iron. After this, explicit dynamic simulation was undertaken to study the same benchmarked impeller materials. Failures and large stress concentrations occurring at the blade-hub leading and trailing edge interface were predicted which has been found to be consistent with some cases outlined in relevant literature. Similarly, trend has also been predicted at the trailing edge of the discharge side of the impeller. Specifically, FV520B was found to withstand the application of the combined rotational and aerodynamic load, for both static and dynamic simulations. Of the three alternative materials investigated, duplex stainless-steel was the only one to satisfy the failure criteria. From static and dynamic simulation of each material, the operation aerodynamic load was found to have little effect on the resultant stress and strain responses. This is consistent with many FEA simulations of impellers seen in literature, wherein the aerodynamic load is often simplified or neglected completely. In both the simulations of benchmark materials, the material data available to the solver greatly impacted the magnitude and behaviour of the material's stress/strain response.