Corrosive fluid effects on volute surface roughness in centrifugal pumps: a computational study

Corrosive fluids, namely, hydrogen peroxide (H2O2), hydrochloric acid (HCl) and sulfuric acid (H2SO4) can be used as a working fluid for volute surface roughness to study its impact on an existing H47 centrifugal pump. To analyse the effects of volute surface roughness, ANSYS student version 2023 software was used - wherein; head rise (H), pump speed (N), discharge rate (Q), inlet pressure and roughness height (h) of 20-40 m, 2000 rpm, 144 m3/h, 0 atm and 0.5 m, were respectively specified as initial and boundary conditions in the computational fluid dynamics (CFD) tool. CFD of volute roughness were respectively simulated for all corrosive fluids to obtain pressure and velocity distribution and profile plots of the analysis using fluid constant properties. The presence of volute wall roughness was observed to increase hydraulic losses in the volute when using corrosive fluids. The hydraulic loss in the volute due to wall roughness is influenced by the viscosity of the respective fluids. Denser fluids, like HCl and H2SO4 required more input power for the same flow rate, highlighting the viscosity-dependent nature of hydraulic losses. Smoothing and refining the volute wall may lead to a significant increase in pump performance without compromising impeller flow conditions. Exploring the effects of smoothing and roughening the volute wall on pump performance should be investigated.