Recent experiments have reported a novel transition to elasto-inertial turbulence in the Taylor–Couette flow of dilute polymer solution. Unlike previously transitions, this newly discovered scenario, dubbed vortex merging and splitting (VMS) transition, occurs centrifugally unstable regime mechanisms underlying it are two-dimensional: becomes chaotic due proliferation events where axisymmetric ...

Bu çal??man?n amac?; fen bilimleri dersinin teknoloji destekli olarak yürütülmesinin ve gerçekle?tirilen Web 2.0 uygulamalar?n?n ortaokul 6. s?n?f ö?rencilerinin fene teknolojiye yönelik tutumlar?na etkisini ortaya koymakt?r. Gerçekle?tirilen çal??mada nicel ara?t?rma yöntemlerinden ön test-son test kontrol gruplu yar? deneysel desen kullan?lm??t?r. Çal??ma grubunu, Kars ilinin Merkez ilçesinde...

Bu araştırmada, ortaokul öğrencilerine uygulanan STEM (Science, Technology, Engineering, Mathematic) etkinliklerinin, öğrencilerin alanına yönelik tutumlarına ve fene motivasyonlarına etkisi incelenmiştir. Araştırma deneme öncesi deneysel desenlerden tek grup ön-son test modelinde yürütülmüş örneklemi Ankara ilindeki bir özel ortaokulda eğitim alan 70 öğrenciden oluşturmaktadır. Öğrencilerden e...

– We study the dynamics of a single polymer subject to thermal fluctuations in a linear shear flow. The polymer is modeled as a finitely extendable nonlinear elastic (FENE) dumbbell. Both orientation and elongation dynamics are investigated numerically as a function of the shear strength, by means of a new efficient integration algorithm. The results are in agreement with recent experiments. In...

Micro–macro simulations of polymeric solutions rely on the coupling between macroscopic conservation equations for the fluid flow and stochastic differential equations for kinetic viscoelastic models at the microscopic scale. In the present work we introduce a novel micro–macro numerical approach, where the macroscopic equations are solved by a finite-volume method and the microscopic equation ...

Using branch continuation in the FENE-P model, we show that finite-amplitude travelling waves borne out of recently discovered linear instability viscoelastic channel flow (Khalid et al. , J. Fluid Mech. vol. 915, 2021, A43) are substantially subcritical reaching much lower Weissenberg ( $Wi$ ) numbers than on neutral curve at a given Reynolds $Re$ number over $Re \in [0,3000]$ . The surprising...

The simulation of flows of viscoelastic fluids is a very challenging domain from the theoretical as well as the numerical modelling point of view. In particular, all the existing methods have failed to solve the high Weissenberg number problem (HWNP). It is therefore clear that new tools are necessary. In this thesis we propose to tackle the problem of the simulation of viscoelastic fluids pres...

Observations are presented of several novel phenomena involved in the dynamics of a pendant drop of viscoelastic micellar fluid falling through air. Generally, when a drop falls a filament forms connecting it to the orifice; the filament eventually breaks due to an instability. The filament dynamics and instabilities reported here are very different from the standard Newtonian and non-Newtonian...