Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 10 of 10 for “"Giesekus"”.
-
Simulation of blood flows in a stenosed and bifurcating artery using finite volume methods and OpenFOAM
… for viscoelastic fluids include the OldroydB, Giesekus, Johnson-Segalman, Finitely Extensible Non-Linear Elastic (FENE), Phan-Thein-Tanner (PTT) models etc. Our Numerical approach is based on the finite volume methods implemented on the OpenFOAM platform. We employ the Giesekus, Oldroyd-B, and …
-
Enhanced Constitutive Theories for Classical Thermoviscoelastic Polymeric Fluids
… It is shown that Maxwell, Oldroyd-B, and Giesekus constitutive models can be described by a single constitutive theory. It is well established that the currently used Maxwell and Oldroyd-B models predict zero normal stress perpendicular to the flow direction. It is shown that this …
-
Effects of the Non-Newtonian Rheology on the Fluid-Structure Interactions in Biological Flows
… flexible filament in Newtonian and viscoelastic (Giesekus and FENE-CR) uniform flows are investigated. It is found that the Reynolds number promotes the flapping motion of the filament. The viscoelasticity of the Giesekus fluid facilitates the flapping motion of the filament. In contrast, the …
-
Modeling of three-dimensional viscoelastic flows with free surfaces using a finite element method
… isothermal, incompressible, creeping flow of a Giesekus fluid with free surfaces at infinite capillary number. The code is an extension of the parallel methods developed by Caola et al. from two- to three-dimensional flows, a restructured and improved version of the three-dimensional code of …
-
Formation of microfibers and nanofibers by capillary-driven thinning of drying viscoelastic filaments
… polymer rheology is described by a single mode Giesekus model with a concentration-dependent shift factor that accounts for compositional dependence of the zero shear rate viscosity and the relaxation time of the fluid. An averaged mass transfer coefficient accounts for evaporation by …
-
Modelling and computational analysis of heat-transfer in multi-geometry and multi-phase flow of Newtonian and non-Newtonian fluids in pipes and channels
… fluids in this thesis are modelled via the Giesekus viscoelastic constitutive equations. For the multi-geometry heat-exchanger problems, the thesis will focus attention on counterflow heat exchangers in cylindrical geometries, specifically counterflow, double-cylinder heat-exchangers. The …
-
The Shear and Extensional Rheology of Polymer Dispersions
… with the viscoelasticity of the fluid. The Giesekus multi-mode model had been used to characterise the fluid. MatLabwas used to obtain a single set of parameters to capture the behaviour in both shear and extensional flow. The unified set of parameters were used on OpenFOAM using the …
-
Development of an efficient finite volume computational platform for the simulation of complex flows of complex fluids governed by the Rolie-Poly model
… existing literature of shear bands using the Giesekus and Johnson-Segalman constitutive equations. The numerical results show good agreement with existing literature for the DEVSS stabilization technique.
-
Simulation of nonisothermal and time-dependent viscoelastic flows
… of the fluid. The non isothermal analog to the Giesekus constitutive equation for the polymer contribution to the stress is then de1ived with the pseudotime approach. The constitutive equations are combined with conservation equations for mass. momentum, and energy to model the nonisothermal …
-
Methods for the integrated design of viscoelastic materials and structural geometry
Design engineers have traditionally selected simple materials, including linear elastic solids and Newtonian fluids, for their designs, and optimize designed systems within the limitations of preselected materials. However, allowing complex materials (e.g., viscoelastic materials and soft solids) …