S053074 Relation between Flow Accelerated Corrosion and Wall Shear Stress Downstream from an Orifice in a Circular Pipe

Abstract

In the present study, to evaluate the effect of local flow field on flow accelerated corrosion (FAC), the distributions of time-averaged and root mean square (RMS) of wall shear stresses downstream from an orifice were measured using a flow vector sensor of micro electro mechanical system (MEMS). The air flow was supplied to a circular pipe from a blow-down wind tunnel. The diameter of the pipe is D = 194 mm and the diameter of the orifice is d = 97 mm, yielding a diameter ratio of 0.5. The measured RMS of wall shear stress was found to qualitatively agree with the numerical results obtained previously by Large-eddy simulation. Experimental data of FAC thinning rates, mass transfer coefficients, and the RMS of wall shear stress were compared and the shape of distributions of them relatively agreed well each other. It indicated that an analogy between momentum and mass transfer is still useful downstream from the orifice.