Sökning: "LOW-REYNOLDS-NUMBER"

Visar resultat 16 - 20 av 27 avhandlingar innehållade ordet LOW-REYNOLDS-NUMBER.

1. 16. Methodologies for RANS-LES interfaces in turbulence-resolving simulations

   Författare :Sebastian Arvidson; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

3. 17. Assessment and Some Improvements of Hybrid RANS-LES Methods

   Författare :Sebastian Arvidson; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 18. Hydrodynamics of plane liquid jets aimed at applications in paper manufacturing

   Författare :Daniel Söderberg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; liquid jet; transition; break-up; stability; wavelet; free surface; waves; streamwise streaks; fibre suspension; headbox; forming; shadowgraph; hot-film; Engineering mechanics; Teknisk mekanik;

   Sammanfattning : Process industries are in general depending, in one way or the other, on fluid mechanics.Specifically, paper manufacturing, which probably is the dominant processindustry in Sweden, is depending on the flow of cellulose fibres suspended in water. LÄS MER

5. 19. The Axisymmetric Turbulent Wake

   Författare :Peter Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis presents a theoretical and experimental study of the turbulent axisymmetric wake. In the theoretical part, an equilibrium similarity solution of the far wake was derived that was found to admit to two different solutions for this flow. LÄS MER

7. 20. Mathematical modelling of flow through thin curved pipes with application to hemodynamics

   Författare :Arpan Ghosh; Vladimir Kozlov; Matts Karlsson; David Rule; Grigory Panasenko; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The problem of mathematical modelling of incompressible flows with low velocities through narrow curvilinear pipes is addressed in this thesis. The main motivation for this modelling task is to eventually model the human circulatory system in a simple way that can facilitate the medical practitioners to efficiently diagnose any abnormality in the system. LÄS MER