Westhoff, Andreas (2013) Spaitial Scaling of Large-Scale Circulations and Heat Transport in turbulent Mixed Convection. Dissertation, Georg-August Universität Göttingen.
![]() |
PDF
93MB |
Official URL: http://hdl.handle.net/11858/00-1735-0000-000D-FD19-2
Abstract
The present study reports an experimental investigation of the scaling of large-scale coherent structures, their dynamics and heat transport in turbulent mixed convection. Based on a concept of spatial scaling, mixed convective air flow was examined by particle image velocimetry and temperature measurements in two rectangular containers with the same geometry and similar characteristic numbers. The dimensions of the container are scaled by a factor five. Due to the unsteady nature of mixed convection in the present configuration and parameter range, the instantaneous velocity vector fields are subjected to a proper orthogonal decomposition and a vortex detecting algorithm in order to identify the predominant coherent structures and their dynamics. It was found that mixed convection is far from equilibrium and comprises numerous of flow states; depending on the ratio of inertia to buoyancy forces. In addition, the study reveals a strong correlation between the dynamics of the large-scale coherent structures and the transport of heat. Based on these characteristic features, mixed convection in the two containers was examined for similitude of the predominant coherent structures and for kinematic similitude. A good accordance of the topology of the large-scale structures and their dynamics was found.
Item URL in elib: | https://elib.dlr.de/81327/ | ||||||
---|---|---|---|---|---|---|---|
Document Type: | Thesis (Dissertation) | ||||||
Title: | Spaitial Scaling of Large-Scale Circulations and Heat Transport in turbulent Mixed Convection | ||||||
Authors: |
| ||||||
Date: | 15 February 2013 | ||||||
Journal or Publication Title: | Niedersächsische Staats- und Universitätsbibliothek Göttingen | ||||||
Refereed publication: | No | ||||||
Open Access: | Yes | ||||||
Gold Open Access: | No | ||||||
In SCOPUS: | No | ||||||
In ISI Web of Science: | No | ||||||
Number of Pages: | 164 | ||||||
Status: | Published | ||||||
Keywords: | Mixed Convection, Large-Scale Circulation, low-frequencies dynamics, Forced Convection, Rayleigh-Benard Convection, Spatial Scaling, heat transport, Proper Orthogonal Decomposition, Particle Image Velocimetry | ||||||
Institution: | Georg-August Universität Göttingen | ||||||
Department: | Promotionsprogramm ProPhys der Georg-August University School of Science (GAUSS) | ||||||
HGF - Research field: | Aeronautics, Space and Transport | ||||||
HGF - Program: | Transport | ||||||
HGF - Program Themes: | Terrestrial Vehicles (old) | ||||||
DLR - Research area: | Transport | ||||||
DLR - Program: | V BF - Bodengebundene Fahrzeuge | ||||||
DLR - Research theme (Project): | V - Projekt Next Generation Train (old) | ||||||
Location: | Göttingen | ||||||
Institutes and Institutions: | Institute of Aerodynamics and Flow Technology > Fluid Systems | ||||||
Deposited By: | Westhoff, Andreas | ||||||
Deposited On: | 15 Apr 2013 12:38 | ||||||
Last Modified: | 31 Jul 2019 19:40 |
Repository Staff Only: item control page