Transcript Slide 1

KNOO CFD @ Manchester: Heat transfer test cases
Test Case 1 :
Mixed convection in vertically flowing heated pipe
(buoyancy aiding or opposing)
Problem specifications:
 Re=2650
 Pr=0.71
 Wall constant heat flux
 Boussinesq approximation
Heat transfer Regimes:
 Gr/Re2=0.000  Forced Convection
 Gr/Re2=0.063  Forced/Mixed Convection
 Gr/Re2=0.087  Re-Laminarization
 Gr/Re2=0.241  Recovery
Relevance to AGR and VHTR
AGR working scheme
Buoyancy aiding or opposing vertical pipe flow
V gradient nearer wall
=> Turbulence decrease
buoyancy aiding
buoyancy opposing
V gradient away from wall
=> Turbulence increase
Nu/Nu0 against ‘buoyancy parameter’, [Hall and Jackson ]
1.8
1.6
Nu/Nu 0
1.4
Launder & Sharma Model
Cotton & Ismael Model
Suga Model
Data of Carr et al (1973)
DNS of You et al (2003)
Data of Easby (1978)
Data of Parlatan et al (1996)
1.2
1
0.8
0.6
0.4
0.01
0.1
Bo
1
Bo  8  104 Gr /(Re 3.425 Pr 0.8 )
10
STAR-CD Quasi DNS [Y. Addad ]
STAR " quasi " DNS r   1.
You et al. DNS
r   0.2
R   6.3
R   8.8
z   18.
z   10.5.
1.5
1.3
Nu/Nu 0
1.1
Launder & Sharma Model (CONVERT)
Large Eddy Simulation (STAR-CD)
Data of Steiner (1971)
Data of Carr et al (1973)
Data of Parlatan et al (1996)
DNS - You et al (2003)
0.9
0.7
0.5
0.3
0.01
0.1
Bo
1
Bo  8  104 Gr /(Re 3.425 Pr 0.8 )
10
K-omega not sensitive to buoyancy effect
1.5
Launder & Sharma Model (CONVERT)
1.3
Suga Non-Linear Eddy Viscosity Model (CONVERT)
k-omega-SST Model (STAR-CD)
k-omega-SST Model (Code_Saturne)
Large Eddy Simulation (STAR-CD)
Nu/Nu 0
1.1
DNS - You et al (2003)
0.9
0.7
0.5
0.3
0.01
0.1
1
Bo
10
Good predictions by V2F models
1.5
Launder & Sharma Model (CONVERT)
k-omega-SST Model (STAR-CD)
1.3
Lien & Durbin v2f Model (STAR-CD)
Manchester v2f Model (Code_Saturne)
Large Eddy Simulation (STAR-CD)
Nu/Nu 0
1.1
DNS - You et al (2003)
0.9
0.7
0.5
0.3
0.01
0.1
1
Bo
10
“standard” STAR k-epsilon model (Lien Chen Leschziner)
1.5
1.3
Nu/Nu 0
1.1
Launder & Sharma Model (CONVERT)
Cotton & Ismael Model (CONVERT)
Suga Non-Linear Eddy Viscosity Model (CONVERT)
Lien-Chen-Leschziner k-eps Model (STAR-CD)
k-omega-SST Model (STAR-CD)
Lien & Durbin v2f Model (STAR-CD)
k-omega-SST Model (Code_Saturne)
Manchester v2f Model (Code_Saturne)
Large Eddy Simulation (STAR-CD)
DNS - You et al (2003)
0.9
0.7
0.5
0.3
0.01
0.1
1
Bo
10
5
Large Eddy
Simulation
k-omega-SST
(Code_Saturne)
15
k-omega-SST
(STAR-CD)
Manchester v2f
(Code_Saturne)
Lien & Durbin
v2f (STAR-CD)
Standard kepsilon (STARCD)
Suga NLEVM
(CONVERT)
Cotton & Ismael
(CONVERT)
Launder &
Sharma
(CONVERT)
DNS of You et
al (2003)
C f x 1000
Nu
Results for Fully-Developed Forced Convection. (no buoyancy)
25
Expt. of Polyakov & Shindin
20
Nusselt number
Friction coefficient
10
Buoyancy aided heated pipe flow
Gr/Re**2 = 0.000
Buoyancy aided heated pipe flow
Gr/Re**2 = 0.087 (relaminarization)
Buoyancy aided heated pipe flow
Gr/Re**2 = 0.087 (relaminarization)
Buoyancy aided heated pipe flow
Gr/Re**2 = 0.087 (relaminarization)
Buoyancy aided heated pipe flow
Gr/Re**2 = 0.241 (recovery)