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Showing result 1 - 5 of 14 swedish dissertations matching the above criteria.

2. 1. Measuring Material Properties through Gradient Based NMR: Diffusion and Imaging

   Author : Ingrid Åslund; Fysikalisk kemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; intracellular diffusion; homogeneous length-scale; material properties; emulsions; yeast suspensions; lamellar phase; NMR; self-diffusion; membrane permeability and bending rigidity;

   Abstract : In this work new methods based Nuclear Magnetic Resonance (NMR) have been developed to measure different kinds of structural properties in soft materials. The advantage of using NMR as a technique to measure material properties is that it is non-destructive, which makes it possible to measure on the actual piece of material that will be used for the application. READ MORE

4. 2. Assessment and Some Improvements of Hybrid RANS-LES Methods

   Author : Sebastian Arvidson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; hybrid RANS-LES; zonal RANS-LES; embedded LES; PDH-LRN; log-layer mismatch; LES length scale; shock boundary-layer interaction;

   Abstract : Motivated by numerical analysis of a shock/boundary-layer interacting (SBLI) flow in a duct, where some typical existing hybrid RANS-LES methods become awkward to give accurate predictions of the shock-induced corner separation bubble, a new hybrid RANS-LES method, has been proposed. The model is based on a low-Reynolds-number (LRN) $k-\omega$ RANS model, which is one of the few models that are capable of giving reasonable predictions for the SBLI flow in RANS computations. READ MORE

5. 3. Methodologies for RANS-LES interfaces in turbulence-resolving simulations

   Author : Sebastian Arvidson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; zonal RANS-LES; aeronautics; RANS-LES interfaces; Hybrid RANS-LES; grey-area mitigation; log-layer mismatch; embedded LES; LES length scale; LES;

   Abstract : Hybrid Reynolds-Average Navier-Stokes (RANS)-Large-Eddy Simulations (LES) techniques are now seen by the aeronautical industry as the most promising turbulence-resolving approaches for complex high-Reynolds-number turbulent flows with regard to cost and accuracy. However, connecting RANS and LES simulated flows is a challenging task and needs special attention in order to increase simulation robustness and accuracy. READ MORE

6. 4. Modeling of magnetohydrodynamic turbulence

   Author : Ola Widlund; KTH; []
   Keywords : turbulence model; magnetohydrodynamic; mhd; magnetohydrodynamic turbulence; computational fluid dynamics; continuous casting;

   Abstract : Conventional one-point turbulence closures have beenextended with an additional transported scalar for modeling ofmagnetohydrodynamic (MHD) turbulence. The new scalar, α ,captures the length scale anisotropy and tendency towardstwo-dimensionality, which is characteristic feature of MHDturbulence, and allows accurate modeling of the Jouledissipation of turbulence. READ MORE

7. 5. Microscopic Dynamics and Structure of some Polymer-based Electrolytes

   Author : DANIEL ANDERSSON; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; segmental motion; neutron scattering; ionic conduction; polymer electrolytes; gel electrolytes; Gaussianity; oligomers; photon correlation; PPO-LiClO4;

   Abstract : The electrolyte is a key component in high-capacity lithium batteries and there is a large demand for improved materials to increase the performance. Polymer-based electrolytes offer advantages in the design of safer and lighter batteries. READ MORE