Petróleo Brasileiro SA (Petrobras) has used computational fluid dynamics (CFD), an analytical simulation tool for studying fluid mechanics, to determine possible causes of and solutions to flow-induced vibrations (FIVs) in a waste heat-recovery steam generator (WHRSG) of the residue fluid catalytic cracking (RFCC) unit at its 53,000-b/d Capuava refinery (Recap) in Mauá, São Paulo, Brazil.