Towards Predicting the Onset of Elastic Turbulence in Complex Geometries

Abstract Flow of complex fluids in porous structures is pertinent many biological and industrial processes. For these applications, elastic turbulence, a viscoelastic instability occurring at low Re—arising from non-trivial coupling fluid rheology flow geometry—is common relevant effect because significant over-proportional increase pressure drop spatio-temporal distortion the field. Therefore, efforts have been made to predict onset turbulence geometries with constrictions. The perturbations streamlines not adequately captured by Deborah Weissenberg numbers. introduction more dimensionless numbers such as M-criterion, which was meant simple pragmatic method instabilities an order-of-magnitude estimate, has successful for simpler geometries. However, are encountered sometimes discrepancies between experimental observation M-criteria prediction encountered. So far mainly attributed emergence disorder. In this study, we employ single channel multiple constrictions varying distance aspect ratios. We show that adjacent can interact via non-laminar field caused combination individual geometry depending (besides other factors) explicitly on This provides intuitive insight conceptual level why predictions precise. Our findings suggest rheological effects implicit controlled length scales than currently employed. translating bulk fluid, determined classical rheometry into effective behaviour requires consideration only one repeat element. open path towards accurate applications will benefit. Article Highlights demonstrate “interact” fields constrictions, implying implicit. concept characterizing independent later back interest may fall short scales, separation control overlap fields. By providing direct evidence illustrating cause shortcoming status-quo, expected impact work challenge augment existing concepts ultimately lead correct turbulence.