Simulation of flow in the human lung is of great practical interest as a means to study the detailed flow patterns within the airways for many physiological applications. While computational simulation techniques are quite mature, lung simulations are particularly complicated due to the vast separation of length scales between upper airways and alveoli. Many past studies have presented numerical results for truncated airway trees, however, there are significant difficulties in connecting such results with respiratory airway models. This article presents a new modeling paradigm for flow in the full lung, based on a conjugate fluid–porous formulation where the upper airway is considered as a fluid region with the remainder of the lung being considered as a coupled porous region. Results are presented for a realistic lung geometry obtained from computed tomography (CT) images, which show the method's potential as being more efficient and practical than attempting to directly simulate flow in the full lung.

References

1.
Tawhai
,
M. H.
, and
Lin
,
C.-L.
,
2010
, “
Image-Based Modeling of Lung Structure and Function
,”
J. Magn. Reson. Imaging
,
32
(
6
), pp.
1421
1431
.
2.
Weibel
,
E. R.
,
1963
,
Morphometry of the Human Lung
,
Springer-Verlag
,
New York
.
3.
Comer
,
J. K.
,
Kleinstreuer
,
C.
,
Hyun
,
S.
, and
Kim
,
C. S.
,
2000
, “
Aerosol Transport and Deposition in Sequentially Bifurcating Airways
,”
ASME J. Biomech. Eng.
,
122
(
2
), pp.
152
158
.
4.
Zhang
,
Z.
,
Kleinstreuer
,
C.
, and
Kim
,
C. S.
,
2001
, “
Flow Structure and Particle Transport in a Triple Bifurcation Airway Model
,”
ASME J. Fluids Eng.
,
123
(
2
), pp.
320
330
.
5.
Zhang
,
Z.
, and
Kleinstreuer
,
C.
,
2002
, “
Transient Airflow Structures and Particle Transport in a Sequentially Branching Lung Airway Model
,”
Phys. Fluids
,
14
(
2
), pp.
862
880
.
6.
Zhang
,
Z.
, and
Kleinstreuer
,
C.
,
2003
, “
Species Heat and Mass Transfer in a Human Upper Airway Model
,”
Int. J. Heat Mass Transfer
,
46
(
25
), pp.
4755
4768
.
7.
Nowak
,
N.
,
Kakade
,
P. P.
, and
Annapragada
,
A. V.
,
2003
, “
Computational Fluid Dynamics Simulation of Airflow and Aerosol Deposition in Human Lungs
,”
Ann. Biomed. Eng.
,
31
(
4
), pp.
374
390
.
8.
van Ertbruggen
,
C.
,
Hirsch
,
C.
, and
Paiva
,
M.
,
2005
, “
Anatomically Based Three-Dimensional Model of Airways to Simulate Flow and Particle Transport Using Computational Fluid Dynamics
,”
J. Appl. Physiol.
,
98
(
3
), pp.
970
980
.
9.
Ma
,
B.
, and
Lutchen
,
K. R.
,
2006
, “
An Anatomically Based Hybrid Computational Model of the Human Lung and Its Application to Low Frequency Oscillatory Mechanics
,”
Ann. Biomed. Eng.
,
34
(
11
), pp.
1691
1704
.
10.
Zhang
,
Z.
,
Kleinstreuer
,
C.
, and
Kim
,
C. S.
,
2008
, “
Airflow and Nanoparticle Deposition in a 16-Generation Tracheobronchial Airway Model
,”
Ann. Biomed. Eng.
,
36
(
12
), pp.
2095
2110
.
11.
Gemci
,
T.
,
Ponyavin
,
V.
,
Chen
,
Y.
,
Chen
,
H.
, and
Collins
,
R.
,
2008
, “
Computational Model of Airflow in Upper 17 Generations of Human Respiratory Tract
,”
J. Biomech.
,
41
(
9
), pp.
2047
2054
.
12.
Luo
,
H. Y.
, and
Liu
,
Y.
,
2008
, “
Modeling the Bifurcating Flow in a CT-Scanned Human Lung Airway
,”
J. Biomech.
,
41
(
12
), pp.
2681
2688
.
13.
Nazridoust
,
K.
, and
Asgharian
,
B.
,
2008
, “
Unsteady-State Airflow and Particle Deposition in a Three-Generation Human Lung Geometry
,”
Inhal. Toxicol.
,
20
(
6
), pp.
595
610
.
14.
Lin
,
C.
,
Tawhai
,
M. H.
,
Lennan
,
G. M.
, and
Hoffman
,
E. A.
,
2009
, “
Multiscale Simulation of Gas Flow in Subject-Specific Models of the Human Lung
,”
IEEE Eng. Med. Biol. Mag.
,
28
(3), pp.
25
33
.
15.
Walters
,
D. K.
, and
Luke
,
W. H.
,
2010
, “
A Method for Three-Dimensional Navier–Stokes Simulations of Large-Scale Regions of the Human Lung
,”
ASME J. Fluids Eng.
,
132
(
5
), p.
051101
.
16.
Comerford
,
A.
,
Förster
,
C.
, and
Wall
,
W. A.
,
2010
, “
Structured Tree Impedance Outflow Boundary Conditions for 3D Lung Simulations
,”
ASME J. Biomech. Eng.
,
132
(
8
), p.
081002
.
17.
Yin
,
Y.
,
Choi
,
J.
,
Hoffman
,
E. A.
,
Tawhai
,
M. H.
, and
Lin
,
C.-L.
,
2010
, “
Simulation of Pulmonary Air Flow With a Subject-Specific Boundary Condition
,”
J. Biomech.
,
43
(
11
), pp.
2159
2163
.
18.
Walters
,
D. K.
, and
Luke
,
W. H.
,
2011
, “
Computational Fluid Dynamics Simulations of Particle Deposition in Large-Scale Multigenerational Lung Models
,”
ASME J. Biomech. Eng.
,
133
(
1
), p.
011003
.
19.
Saksono
,
P. H.
,
Nithiarasu
,
P.
, and
Sazonov
,
I.
,
2012
, “
Numerical Prediction of Heat Transfer Patterns in a Subject-Specific Human Upper Airway
,”
ASME J. Heat Transfer
,
134
(
3
), p.
031022
.
20.
Tsuda
,
A.
,
Henry
,
F. S.
, and
Butler
,
J. P.
,
1995
, “
Chaotic Mixing of Alveolated Duct Flow in Rhythmically Expanding Pulmonary Acinus
,”
J. Appl. Physiol.
,
79
(
3
), pp.
1055
1063
.
21.
Darquenne
,
C.
, and
Paiva
,
M.
,
1996
, “
Two- and Three-Dimensional Simulations of Aerosol Transport and Deposition in Alveolar Zone of Human Lung
,”
J. Appl. Physiol.
,
80
(
4
), pp.
1401
1414
.
22.
Lee
,
D. Y.
, and
Lee
,
J. W.
,
2003
, “
Characteristics of Particle Transport in an Expanding or Contracting Alveolated Tube
,”
J. Aerosol Sci.
,
34
(
9
), pp.
1193
1215
.
23.
Karl
,
A.
,
Henry
,
F. S.
, and
Tsuda
,
A.
,
2004
, “
Low Reynolds Number Viscous Flow in an Alveolated Duct
,”
ASME J. Biomech. Eng.
,
126
(
4
), pp.
420
429
.
24.
Sznitman
,
J.
,
Heimsch
,
F.
,
Heimsch
,
T.
,
Rusch
,
D.
, and
Rösgen
,
T.
,
2007
, “
Three-Dimensional Convective Alveolar Flow Induced by Rhythmic Breathing Motion of the Pulmonary Acinus
,”
ASME J. Biomech. Eng.
,
129
(
5
), pp.
658
665
.
25.
Tsuda
,
A.
,
Henry
,
F. S.
, and
Butler
,
J. P.
,
2008
, “
Gas and Aerosol Mixing in the Acinus
,”
Respir. Physiol. Neuro.
,
163
(
1
), pp.
139
149
.
26.
Sznitman
,
J.
,
Heimsch
,
T.
,
Wildhaber
,
J. H.
,
Tsuda
,
A.
, and
Rösgen
,
T.
,
2009
, “
Respiratory Flow Phenomena and Gravitational Deposition in a Three-Dimensional Space-Filling Model of the Pulmonary Acinar Tree
,”
ASME J. Biomech. Eng.
,
131
(
3
), p.
031010
.
27.
Kumar
,
H.
,
Tawhai
,
M. H.
,
Hoffman
,
E. A.
, and
Lin
,
C.-L.
,
2009
, “
The Effects of Geometry on Airflow in the Acinar Region of the Human Lung
,”
J. Biomech.
,
42
(
11
), pp.
1635
1642
.
28.
Harding
,
E. M.
, and
Robinson
,
R. J.
,
2010
, “
Flow in a Terminal Alveolar Sac Model With Expanding Walls Using Computational Fluid Dynamics
,”
Inhal. Toxicol.
,
22
(
8
), pp.
669
678
.
29.
Li
,
Z.
, and
Kleinstreuer
,
C.
,
2011
, “
Airflow Analysis in the Alveolar Region Using the Lattice-Boltzmann Method
,”
Med. Biol. Eng. Comput.
,
49
(
4
), pp.
441
451
.
30.
Ma
,
B.
, and
Darquenne
,
C.
,
2011
, “
Aerosol Deposition Characteristics in Distal Acinar Airways Under Cyclic Breathing Conditions
,”
J. Appl. Physiol.
,
110
(
5
), pp.
1271
1282
.
31.
Kumar
,
H.
,
Tawhai
,
M. H.
,
Hoffman
,
E. A.
, and
Lin
,
C.-L.
,
2011
, “
Steady Streaming: A Key Mixing Mechanism in Low-Reynolds-Number Acinar Flows
,”
Phys. Fluids
,
23
(
4
), p.
041902
.
32.
Owen
,
M. R.
, and
Lewis
,
M. A.
,
2001
, “
The Mechanics of Lung Tissue Under High-Frequency Ventilation
,”
SIAM J. Appl. Math.
,
61
(
5
), pp.
1731
1761
.
33.
Lande
,
B.
, and
Mitzner
,
K. R. W.
,
2006
, “
Analysis of Lung Parenchyma as a Parametric Porous Medium
,”
J. Appl. Physiol.
,
101
(
3
), pp.
926
933
.
34.
DeGroot
,
C. T.
, and
Straatman
,
A. G.
,
2012
, “
Numerical Results for the Effective Flow and Thermal Properties of Idealized Graphite Foam
,”
ASME J. Heat Transfer
,
134
(
4
), p.
042603
.
35.
DeGroot
,
C. T.
, and
Straatman
,
A. G.
,
2011
, “
A Finite-Volume Model for Fluid Flow and Nonequilibrium Heat Transfer in Conjugate Fluid-Porous Domains Using General Unstructured Grids
,”
Numer. Heat Transfer, Part A
,
60
(
4
), pp.
252
277
.
36.
Demirdzić
,
I.
, and
Muzaferija
,
S.
,
1995
, “
Numerical Method for Coupled Fluid Flow, Heat Transfer and Stress Analysis Using Unstructured Moving Meshes With Cells of Arbitrary Topology
,”
Comput. Methods Appl. Mech. Eng.
,
125
(
1–4
), pp.
235
255
.
37.
Demirdzić
,
I.
, and
Perić
,
M.
,
1990
, “
Finite Volume Method for Prediction of Fluid Flow in Arbitrarily Shaped Domains With Moving Boundaries
,”
Int. J. Numer. Methods Fluids
,
10
(
7
), pp.
771
790
.
38.
Thomas
,
P. D.
, and
Lombard
,
C. K.
,
1979
, “
Geometric Conservation Law and Its Application to Flow Computations on Moving Grids
,”
AIAA J.
,
17
(
10
), pp.
1030
1037
.
39.
Demirdzić
,
I.
, and
Perić
,
M.
,
1988
, “
Space Conservation Law in Finite Volume Calculations of Fluid Flow
,”
Int. J. Numer. Methods Fluids
,
8
(
9
), pp.
1037
1050
.
40.
Venkatakrishnan
,
V.
, and
Mavriplis
,
D. J.
,
1996
, “
Implicit Method for Computation of Unsteady Flows on Unstructured Grids
,”
J. Comput. Phys.
,
127
(
2
), pp.
380
397
.
41.
Tuković
,
Z.
, and
Jasak
,
H.
,
2012
, “
A Moving Mesh Finite Volume Interface Tracking Method for Surface Tension Dominated Interfacial Fluid Flow
,”
Comput. Fluids
,
55
, pp.
70
84
.
42.
Yushkevich
,
P. A.
,
Piven
,
J.
,
Hazlett
,
H. C.
,
Smith
,
R. G.
,
Ho
,
S.
,
Gee
,
J. C.
, and
Gerig
,
G.
,
2006
, “
User-Guided 3D Active Contour Segmentation of Anatomical Structures: Significantly Improved Efficiency and Reliability
,”
Neuroimage
,
31
(
3
), pp.
1116
1128
.
43.
Rosset
,
A.
,
Spadola
,
L.
, and
Ratib
,
O.
,
2004
, “
OsiriX: An Open-Source Software for Navigating in Multidimensional DICOM Images
,”
J. Digit. Imaging
,
17
(
3
), pp.
205
216
.
44.
West
,
J. B.
,
2008
,
Respiratory Physiology: The Essentials
,
Lippincott Williams & Wilkins
,
Baltimore, MD
.
45.
Werner
,
R.
,
Ehrhardt
,
J.
,
Schmidt
,
R.
, and
Handels
,
H.
,
2008
, “
Modeling Respiratory Lung Motion—A Biophysical Approach Using Finite Element Methods
,”
Proc. SPIE
,
6916
, p.
69160N
.
46.
DeGroot
,
C. T.
,
2012
, “
Numerical Modelling of Transport in Complex Porous Media: Metal Foams to the Human Lung
,” Ph.D. thesis, University of Western Ontario, London, ON, Canada.
47.
Gehr
,
P.
,
Bachofen
,
M.
, and
Weibel
,
E. R.
,
1978
, “
The Normal Human Lung: Ultrastructure and Morphometric Estimation of Diffusion Capacity
,”
Respir. Physiol.
,
32
(
2
), pp.
121
140
.
48.
Kamschulte
,
M.
,
Schneider
,
C. R.
,
Litzbauer
,
H. D.
,
Tscholl
,
D.
,
Schneider
,
C.
,
Zeiner
,
C.
,
Krombach
,
G. A.
,
Ritman
,
E. L.
,
Bohle
,
R. M.
, and
Langheinrich
,
A. C.
,
2013
, “
Quantitative 3D Micro-CT Imaging of Human Lung Tissue
,”
Fortschr. Röntgenstr.
,
185
(
9
), pp.
869
876
.
49.
Mathur
,
S. R.
, and
Murthy
,
J. Y.
,
1997
, “
Pressure Boundary Conditions for Incompressible Flow Using Unstructured Meshes
,”
Numer. Heat Transfer B
,
32
(
3
), pp.
283
298
.
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