Two phase natural convection: CFD simulations and PIV measurement

Buoyancy induced flow and heat transfer are important phenomena in a wide range of engineering systems e.g. electronics and photovoltaics cooling, thermosiphon heat exchangers, solar-thermal heat absorbers, passive decay heat removal systems, etc. Such systems are subject to thermal stratification....

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Chemical engineering science Jg. 66; H. 14; S. 3152 - 3171
Hauptverfasser: Gandhi, Mayurkumar S., Sathe, Mayur J., Joshi, Jyeshtharaj B., Vijayan, Pallippattu K.
Format: Journal Article Tagungsbericht
Sprache:Englisch
Veröffentlicht: Kidlington Elsevier Ltd 15.07.2011
Elsevier
Schlagworte:
Applied sciences
boiling
Chemical engineering
Computational fluid dynamics
Computational fluid dynamics (CFD)
Computer simulation
computer software
Convection
cooling
electronics
energy
Estimates
Exact sciences and technology
Heat and mass transfer. Packings, plates
heat exchangers
Heat exchangers and evaporators
Heat transfer
Mathematical models
mixing
Mixing number
Natural convection
Particle Image Velocimetry (PIV)
phase transition
Pool boiling
Stratification
Stratification number
systems engineering
temperature profiles
turbulent flow
Two phase
wavelet
Particle Image Velocimetry (PIV)
Natural convection
Mixing number
Stratification number
Pool boiling
Computational fluid dynamics (CFD)
Mixing
Turbulent flow
Cooling
Computational fluid dynamics
Phase change
Energy distribution
Buoyancy
Heat transfer coefficient
Rayleigh number
Modeling
Temperature measurement
Thermosyphon
Heat exchanger
Signal processing
Particle image velocimetry
Software
Stratification
Heat transfer
ISSN:0009-2509, 1873-4405
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Buoyancy induced flow and heat transfer are important phenomena in a wide range of engineering systems e.g. electronics and photovoltaics cooling, thermosiphon heat exchangers, solar-thermal heat absorbers, passive decay heat removal systems, etc. Such systems are subject to thermal stratification. The objective of the present work is to study the single phase and two phase (boiling) natural convection accompanied by thermal stratification. We carried out velocity and temperature measurements in a rectangular tank (0.8×0.6×0.6 m 3) fitted with (a) a central tube, and (b) a 10 tube assembly; which form the heat transfer surface. Flows were measured using Particle Image Velocimetry (PIV). Additionally, computational fluid dynamic (CFD) simulations of these systems were performed: first with an assumption of no-boiling (i.e. no phase change) near the heat transfer surfaces; for which we used the open source CFD code OpenFOAM-1.6. For two phase simulations, we used the boiling model of Ganguli et al. (2010) and carried out simulations using the commercial software FLUENT 6.3. The extent of stratification and mixing has been investigated for a range of Rayleigh numbers from 4.34×10 11 to 2.59×10 14. The flow information obtained from PIV was analyzed for insights into the dynamics of turbulent flow structures. We used the signal processing technique of discrete wavelet transform (DWT) for this purpose. From the analysis, we were able to estimate the size, velocity and energy distribution of turbulent structures in our flows. This information was used to estimate wall heat transfer coefficients. A good agreement was observed between the predicted and the experimental values of heat transfer coefficients.
Bibliographie:http://dx.doi.org/10.1016/j.ces.2011.02.060
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ObjectType-Article-2
ObjectType-Feature-1
ISSN:0009-2509
1873-4405
DOI:10.1016/j.ces.2011.02.060