Titre :
|
Numerical and experimental investigations of newtonian and non-newtonian flow in annular gaps with scraper blades
|
Auteurs :
|
M. Stranzinger ;
SWISS FEDERAL INSTITUTE OF TECHNOLOGY -ZURICH
|
Type de document :
|
thèse/mémoire
|
Année de publication :
|
1999
|
Format :
|
185 p.
|
Langues:
|
= Anglais
|
Catégories :
|
MATERIAUX
|
Mots-clés:
|
FLUIDE NON NEWTONIEN
;
TRANSFERT DE MASSE
;
TRANSFERT DE CHALEUR
;
IMAGERIE
;
METHODE NUMERIQUE
;
EXPERIMENTATION
|
Résumé :
|
This work presents numerical and experimental investigations of narrow annular gap flows using an apparatus with an inner cylinder as rotor, with two attached scraper blades, and an outer cylinder acting as a stator (with a rotor/stator cylinder ratio of 0.8). Applications in industry are Narrow Gap-Scraped Surface Heat Exchangers (NG-SSHE) or Narrow Gap-Shear Crystallizers (NG-SC) developed by the Laboratory of Food Process Engineering at ETH Zürich. Narrow annular gap apparatus with wall scraping tools are the basis of a new type of continuous reactor principle for the mechanical and thermal treatment of fluid systems. This principle combines the advantages of : 1. narrow mechanical stress distribution ; 2. narrow residence time distribution ; 3. optimized "thin layer" heat and mass transfer. A finite volume method (FVM: the numerical part) and a digital-particle image velocimetry method (D-PIV : the experimental part) are employed in the investigation. A variety of rotor velocities represented by a rotational Reynolds number (parameter Re) and a variety of scraper blades angles between 30° and 150° (paameter beta) are considered for newtonian and inelastic non-newtonian shear-thinning fluids (modelled with power-law exponents between n=0.2 and 1.0).
|
Diplôme :
|
Thèse de Doctorat, Swiss Federal Institute of Technology Zürich
|