Titre :
|
An investigation of void fraction in the stratified/annular flow regions in smooth, horizontal tubes
|
Auteurs :
|
D. Graham ;
H. Kopke ;
M. Wilson ;
D. Yashar ;
J. Chato ;
T. Newell
|
Type de document :
|
rapport
|
Editeur :
|
Urbana Champaign : University of Illinois, 1999
|
Format :
|
19 p.
|
Langues:
|
= Anglais
|
Catégories :
|
TECHNIQUE FRIGORIFIQUE
|
Mots-clés:
|
REFRIGERANT
;
ECOULEMENT DIPHASIQUE
|
Résumé :
|
Refrigerants R134a and R410A have been used for void fraction measurements in smooth horizontal tubes with diameters between 4mm and 7mm. Quality and mass flux were varied from 5% to 90% and 75kg/m²-s to 700kg/m²_s, respectively. Two test loops, one for condensing flows at 35C and the other for evaporating flows at 5C, were used in the investigation. Results show that near the transition from annular to stratfied flow void fraction changed from viscous-inertial dependence to gravitational-inertia dominated dependence. An important feature observed is the annular flow region's relative insensitivity to mass flux while the border region between annular and stratified flows is characterized by strong mass flux dependence.
|
Source :
|
Report, vol ACRC TR 144
|