Numerical Investigation of Turbulent Flow around a Rotating Stepped Cylinder for Corrosion Study

Direct numerical simulation has been carried out for turbulent flow set up by a rotating cylinder with two backward‐facing steps axisymmetrically mounted in the circumferential direction. This flow geometry creates a qualitatively similar flow pattern as observed near a sudden pipe expansion or a plane backward‐facing step, characterized by flow separation and reattachment. A region of intense turbulence intensity and high wall‐shear‐stress fluctuations is formed in the recirculating region downstream of the step, where high mass‐transfer capacity was also experimentally observed. Since corrosion is frequently mass‐transfer controlled, our findings put forward this apparatus as a useful tool for future corrosion research.