Prediction of hydrodynamic instability in the curved ducts by means of semi-analytical and ANN approaches

Abstract

Curved ducts with non-circular cross-sectional geometry have significant applications in different industries. Hydrodynamic stability in these curved ducts is an interesting issue in field of fluid mechanics. In the present study, the linear hydrodynamics stability of fluid flow in the curved rectangular duct is semi-analytically investigated. Then, the hydrodynamic stability in these ducts is estimated via using artificial neural networks (ANNs). To this accomplishment, critical Dean number (Dn c ) is estimated under various aspect ratios and curvature ratios. Based on the semi-analytical results, the Dn c is increased by curvature ratio enhancement. In addition, irregular variation on trend of Dn c is found by an enhancement in the aspect ratio. Moreover, maxima of mean square error and minima of correlation coefficient for intended ANN are obtained 0.00144 and 0.98621, respectively. Finally, predictive equation is suggested to estimate of Dn c using weights and bias of designed ANN. • Hydrodynamics instability in curved rectangular duct is studied by using semi-analytical and ANNs approaches. • Effects of different aspect ratios and curvature ratios on hydrodynamics instability are evaluated. • An equation to predict of critical Dean number in curved ducts by using ANNs is proposed.