Post on 17-Dec-2015
Numerical Modeling and Simulation of Fluid Flow and Heat Transfer in
Engineering Applications
Son H. Ho, Ph.D.Center for Advanced Turbines and Energy Research
University of Central Florida
Room 288, Building ENG I, University of Central Florida – February 24, 2009
Agenda
1. Zero Boil-Off (ZBO) Storage of Cryogenic Liquid Hydrogen (LH2)
2. HVAC&R Indoor Spaces – Thermal Comfort and Contaminant Removal
3. Modeling and Design Micropump
4. Portable Blood Cooling System
5. Other Works
Governing Equations(Incompressible & Constant Property Fluid Flow)
• Conservation of mass:
• Conservation of momentum:
• Conservation of energy:
• Conservation of mass for water vapor:
• Conservation of mass for contaminant gas:
wDwt
waw
2/
u
0 u
refTTpt
guuuu 2
TkTt
Tcp
2
u
cDct
cac
2/
u
LH2 in Space & Automotive Applications
Centaur upper stage – liquid hydrogen/liquidOxygen propelled rocket
Transport of liquid hydrogen used in space applications.
Hydrogen tank in a car’s trunk.
Hydrogen Hummer (converted by Intergalactic Hydrogen).
Shelby Cobras (Hydrogen Car Co.)
Cryogenic Liquid Hydrogen Storage Tank with Lateral Pump-Nozzle Unit
•Fluid: LH2•3-D Model
•Steady-State Analysis
CryocoolerHeat exchanger
Controller
Solar array
Pump-nozzle unit
Tank wall
Insulation
Heat pipe
Liquid cryogen
Radiator
Condenser
EvaporatorHeat flux from surroundings
3-D Model and Dimensions
3-D Hexahedral-Element Mesh
Distribution of Velocity, m/s
Streamlines
Speed
Velocity vector and speed
Distribution of Temperature, K
(a) Conformal slice plot (b) Isosurfaces
(c) Axial planar slice plot, front (d) Axial planar slice plot, back
HVAC&R Applications
Refrigerated Warehouse
Hospital Operating Room
Refrigerated Warehouse with Ceiling Type Cooling Unit
•Fluid: Air•Two- and Three-Dimensional Models
•Steady-State Analysis
2-D and 3-D Models
2-D and 3-D Mesh
Quadrilateral Elements
Hexahedral Elements
Streamlines and Speed, m/s Temperature, °C
2-D Simulation Results
3-D Simulation Results
(a) Streamlines. (b) Speed, m/s.
(c) Pressure, Pa. (d) Temperature, °C.
Thermal Comfort Enhancement using Ceiling Fan in Air-Conditioned Room
•Fluid: Air Mixture (dry air + water vapor)•Two-Dimensional Model•Steady-State Analysis
2-D Model of Air-Conditioned Room with Ceiling Fan
2-D Simulation Results
Streamlines and speed, m/s.
Temperature, °C.
Streamlines and speed, m/s.
Temperature, °C.
(a) Ceiling fan not running (b) Ceiling fan running
3-D Simulation Results
(a) Streamlines (b) Speed, m/s
(c) Temperature, °C (d) Relative humidity, %
PMV Distributions
(a) Ceiling fan not running (b) Ceiling fan running
Thermal Comfort and Contaminant Removal in Hospital Operating Room
•Fluid: Air Mixture (dry air + water vapor + contaminant gas)•Three-Dimensional Model
•Steady-State Analysis
Three-Dimensional Model
3-D Hexahedral-Element Mesh
3-D Simulation Results
Streamlines Speed, m/s
Temperature, °C Contaminant concentration, mg/kg air
Journal1. Ho, S. H., Rosario, L., and Rahman, M. M., “Three-dimensional analysis for hospital operating room thermal comfort and
contaminant removal,” Applied Thermal Engineering (In press, available online 13 November 2008).2. Ho, S. H., Rosario, L., and Rahman, M. M., “Thermal comfort enhancement by using a ceiling fan,” Applied Thermal Engineering
(In press, available online 25 July 2008).3. Ho, S. H. and Rahman, M. M., “Nozzle injection displacement mixing in a zero boil-off hydrogen storage tank,” Int. J. Hydrogen
Energy 33 (2) (2008) pp. 878-888.4. Ho, S. H. and Rahman, M. M., “Three-dimensional analysis for liquid hydrogen in a cryogenic storage tank with heat pipe-pump
system,” Cryogenics 48 (1-2) (2008), pp. 31-41.5. Kaw, A. K. and Ho, S. H., “On introducing approximate solution methods in theory of elasticity,” Comput. Appl. Eng. Educ. 14 (2)
(2006), pp. 120-134.
Conference1. Meckler, M. and Ho, S. H., “Integrate CHP to improve overall corn ethanol economics,” Proceedings of 2008 ASME International
Mechanical Engineering Congress and Exposition, IMECE2008-66295, Nov. 2008, Boston, Massachusetts.2. Ho, S. H. and Rahman, M. M., “Transient thermal analysis of cryogenic liquid hydrogen tank with active circulation,” Proceedings
of Energy Sustainability 2007, ES2007-36195, Jun. 2007, Long Beach, California.3. Ho, S. H., Rosario, L. and Rahman, M. M., “Numerical analysis of thermal behavior in a refrigerated warehouse,” Proceedings of
2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006-15415, Nov. 2006, Chicago, Illinois.4. Ho, S. H. and Rahman, M. M., “Zero boil-off cryogenic liquid hydrogen storage tank with axial cold-spray system,” Proceedings
of 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006-15341, Nov. 2006, Chicago, Illinois.5. Rahman, M. M., Ho, S. H., and Rosario, L., “Review and some research results on hydrogen liquefaction and storage,”
Proceedings of the International Conference on Mechanical Engineering 2005, ICME2005, Dec. 2005, Dhaka, Bangladesh.6. Ho, S. H., Rosario L., and Rahman, M. M., “Effect of using ceiling fan on human thermal comfort in air-conditioned space,”
Proceedings of AIAA 3rd International Energy Conversion Engineering Conference and Exhibit (IECEC), AIAA-2005-5734, Aug. 2005, San Francisco, California.
7. Ho, S. H. and Rahman, M. M., “Three-dimensional analysis of liquid hydrogen cryogenic storage tank,” Proceedings of AIAA 3rd International Energy Conversion Engineering Conference and Exhibit (IECEC), AIAA-2005-5712, Aug. 2005, San Francisco, California.
8. Ho, S.H., Rosario, L., and Rahman, M.M., “Analysis of thermal comfort and contaminant removal in an office room with underfloor air distribution system,” Proceedings of 2005 ASME Summer Heat Transfer Conference, HT2005-72437, Jul. 2005, San Francisco, California.
9. Rahman, M. M. and Ho, S. H., “Zero boil-off cryogenic storage of hydrogen,” NHA 2005 Proceedings of Hydrogen Conference, Mar. 2005, Washington, D.C.
10. Ho, S. H., Rosario, L., and Rahman, M. M., “Predictions of relative humidity and temperature in an operating room,” Proceedings of 2004 ASME International Mechanical Engineering Congress and Exposition, IMECE2004-61372, Nov. 2004, Anaheim, California.
Publications
Mesh Development for Indoor Environmental CFD Modeling
Geometry Decomposition and Meshing for 2-D Model
S = 0.1 m, H = 0.05 m, N = 3 and R = 1.5. 1496 square elements (58%) in total 2570 quadrilateral elements.
Geometry Decomposition for 3-D Model (1)
Geometry Decomposition for 3-D Model (2)
Meshing 3-D Model using Encapsulation Techniques (1)
Meshing 3-D Model using Encapsulation Techniques (2)
3-D Mesh: Layers of Refined Element Mesh on Fluid-Solid Interfaces
3-D Mesh: 35140 Cubical Elements (62%) in total of 56290 Hexahedral Elements
Modeling and Design Micropump
Diaphragm micropump with passive check-valves
Destination
Inlet valve
Outlet valve
Pump chamber
Pump chamber
Pump chamber
p1
p2
s s
1 1 2 2
d d
Diaphragm
Source
1
2 2
Valve discs
z
Vdead
p2*
p1*
p(t)
p(t)
ΔV
22
1 1
1
Pump chamber: mathematical model
outoutinin QQdt
dV
dt
dp
K
V
dt
dwAQQ
whA
K
dt
dpoutin
ppQin 11 22 ppQout
whAV
Pump chamber: Simulink model
Qin
Qout
1/3
zeta
0.8
h
TriangleWave Scope: w
Scope: p
Scope: Qacc
Scope: Q
Product3
Product2
Product1
Product
110000
P2
92000
P1
Outlet valve
2.23e9
K
1s
Integrator1
1s
Integrator
Inlet valve
Divide
du/dt
Derivative
1/57
C2
1/57
C1
Add1
78.54
A
ppH
pRQin
1
1
22
ppH
pRQout
Pump chamber: simulation results
Thermopneumatic micropump
Diaphragm deflection
action membraneby resisted load
3
sprestresseby resisted load
0
action bendingby resisted load
3
2 13
84
13
16
a
w
a
E
a
w
aa
w
a
Eppa
321 wBwBppa
20
4
3
214
13
16
aa
EB
42 13
8
a
EB
AwwaV 2deflection
1
0
2 du
Temperature–deflection relationship
aa h
w
p
wBwBTT 11
0
321
0
44
33
2210 1 wCwCwCwCTTa
aaa hp
BC
p
BC
hp
BC
hp
BC
0
24
0
23
0
12
0
11 ,,,
Temperature vs. deflection
0
50
100
150
200
250
300
350
400
0 20 40 60 80 100 120Temperature rise, K
Def
lect
ion,
µm
Measured (Wego et al., 2001)
ζ = 1/2 (Wego et al., 2001)
ζ = 0.458 (s. s. edge model)
ζ = 1/3 (clamped edge model)
ζ = 0.396 (average model)
Actuation chamber: math. model
easass
sps WTTGdt
dTcm ,
dt
dwApTTGTTG
dt
dTcm afafaasas
aava ,
eaa WTTD
dt
dTD 021
3
42
32101
44
33
22102
432 wCwCwCCTD
wCwCwCwCTDW
dt
dw e
Actuation chamber: Simulink model
wInput: Heating Power
-C-
zeta
-C-
p0
0.8
h_a
308
T0
MATLABFunction
T(w)/T0
MATLABFunction
T'(w)/T0
Scope: w
Scope: W'e
Pulse
Product4
Product3
Product2
Product1
1s
Integrator
Divide3
Divide2
Divide1
Divide
-K-
D2
-K-
D1
-C-
B2
-C-
B1
Add
Actuation chamber: simulation results
Experimental data
Thermopneumatic micropump: Simulink modelw
Input: Heating Power
Qin
Qout
1/3
zeta1
1/3
zeta
0.8
h_a
0.8
h
308
T0
MATLABFunction
T(w)/T0
MATLABFunction
T'(w)/T0
Scope: w1
Scope: w
Scope: p
Scope: W'e
Scope: Qacc
Scope: Q
Pulse
Product7
Product6
Product5
Product4
Product3
Product2
Product1
Product
110000
P2
92000
P1
Outlet valve
2.23e9
K
1s
Integrator2
1s
Integrator1
1s
Integrator
Inlet valve
Divide4
Divide3
Divide2
Divide1
Divide
du/dt
Derivative
-K-
D2
-K-
D1
1/57
C2
1/57
C1
-C-
B2
-C-
B1
Add1
Add
78.54
A
Thermopneumatic micropump: simulation results
Portable Blood Cooling System
Simulation Results
(a) Three-dimensional model (b) Temperature boundary plot
(c) Temperature slice plot (d) Temperature isosurface plot
Cooling Cylinder: math. model
gv
v
fw
gvfg
fw
gvfgw
v
hmQ
m
dT
dum
dT
dumuu
dT
dvm
dT
dvmvv
T
m
m
dt
d
outout
out
1
0
011
vwv mdt
dm
dt
dmout
0dt
dT
dT
dvm
dt
dT
dT
dvm
dt
dmv
dt
dmv f
wg
vw
fv
g
gvfw
gv
wf
vg hmQ
dt
dT
dT
dum
dt
dT
dT
dum
dt
dmu
dt
dmu outout
Cooling Cylinder (Isothermal case): Simulink model
Initial conditions
Rate of vapor removed
m_v(0) & m_w(0)
f(u)
m_dot_out
30
m (g)
V-Cat
VectorConcatenate510
V (cm^3)
22.22
T0
Ug
Uf
Vg
Vf
m.
out
0
1 1
Vg Vf
Scope
T
P_satv_gv_f
u_gu_f
h_gh_f
Properties of saturated water
P_sat, kPa
1s
Integrator1
1sxo
Integrator
Dot Product
Inv
Inv
Clock
Other Works
Applied Mechanics Lab (Vietnam, 1995 – 2001)
8051-based Application (2003)
Click to play video clip
Thank You!