A three-dimensional numerical modeling of airflow in the human pharynx using an anatomically accurate model was conducted. The pharynx walls were assumed to be passive and rigid. The results showed that the pressure drop in the pharynx lies in the range 200-500 Pa. The onset of turbulence was found to increase the pressure drop by 40 percent. A wide range of pharynx geometries covering three sleep apnea treatment therapies (CPAP, mandibular repositioning devices, and surgery) were modeled and the resulting flow characteristics were investigated and compared. The results confirmed that the airflow in the pharynx lies in the laminar-to-turbulence transitional flow regime and thus, a subtle change in the morphology caused by these treatment therapies can significantly affect the airflow characteristics.
Issue Section:
Technical Papers
1.
Carew
E. O.
Pedley
T. J.
1997
, “An Active Membrane Model for Peristaltic Pumping: 1—Periodic Activation Waves in an Infinite Tube
,” ASME JOURNAL OF BIOMECHANICAL ENGINEERING
, Vol. 119
, pp. 66
–76
.2.
Elad
K.
Roger
D. K.
Shapiro
A. H.
1987
, “Choking Phenomena in Lung-Like Model
,” ASME JOURNAL OF BIOMECHANICAL ENGINEERING
, Vol. 109
, pp. 1
–9
.3.
Elad, D., Liebenthal, R., and Einav, S., 1991, “Simulation of Air Flow in the Human Nasal Cavity,” Proc. 4th FIDAP Users’ Conference, Evanston, IL.
4.
FIDAP, 1993, Users’ and Theory Manuals, Version 7.0, Fluid Dynamics International, Evanston, IL.
5.
Hahn, I., 1992, “Modeling Nasal Airflow and Olfactory Mass Transport,” Ph.D. Thesis, University of Pennsylvania, Philadelphia, PA.
6.
Hanjalic
K.
1994
, “Advanced Turbulence Closure Models: A View of Current Status and Future Prospects
,” International Journal of Heat and Fluid Flow
, Vol. 15
, No. 3
, pp. 178
–203
.7.
Isono, S., and Remmers, J. E., 1993, “Anatomy and Physiology of Upper Airway Obstructions,” Principles and Practice of Sleep Medicine. Kryger, M. H., Roth, T., and Dement, W. C., eds., W. B. Saunders Company, Philadelphia, PA, pp. 642–655.
8.
Kamm
R. D.
Pedley
T. J.
1989
, “Flow in Collapsible Tubes: A Brief Review
,” ASME JOURNAL OF BIOMECHANICAL ENGINEERING
, Vol. III
, pp. 177
–179
.9.
Keyhani
K.
Scherer
P. W.
Hahn
I.
Mozell
M. M.
1993
, “Modeling of Airflow in the Human Nasal Cavity
,” Advances in Bioengineering
, ASME BED-Vol. 26
, pp. 299
–302
.10.
Launder
B. E.
Spalding
D. B.
1974
, “The Numerical Computation of Turbulent Flow
,” Computer Methods in Applied Mechanics and Engineering
, Vol. 3
, pp. 269
–289
.11.
Leger
D.
1994
, “The Cost of Sleep-Related Accidents: A Report for the National Commission on Sleep Disorders
,” Sleep
, Vol. 17
, No. 1
, pp. 84
–93
.12.
Luo
X. Y.
Pedley
T. J.
1996
, “A Numerical-simulation of Unsteady-Flow in a 2-dimensional Collapsible Channel
,” J. Fluid Mech.
, Vol. 314
, pp. 191
–225
.13.
Lynch
D. G.
Waters
S. L.
Pedley
T. J.
1996
, “Flow in a Tube With Nonuniform, Time-Dependent Curvature—Governing Equations and Simple Examples
,” J. Fluid Mech.
, Vol. 323
, pp. 237
–265
.14.
National Commission on Sleep Disorders Research, 1993, “Wake-up America: A National Sleep Alert,” Vol. 1, National Institute of Health, Bethesda, MD.
15.
Pack, A. I., 1993, “Identifying Patients With Sleep Apnea Syndrome,” Sleep Medicine Review, Vol. 1, No. 4.
16.
Rodi, W., 1980, “Turbulence Models and Their Application in Hydraulics,” International Association for Hydraulic Research, Netherlands.
17.
Schmidt, R. C., and Patankar, S. V., 1987, “Prediction of Transition on a Flat Plate Under the Influence of Free-Stream Turbulence Using Low-Reynolds-Number Two-Equation Turbulence Model,” ASME Paper No. 87-HT-32.
18.
Tutty
O. R.
Pedley
T. J.
1994
, “Unsteady-Flow in a Nonuniform Channel—A Model for Wave Generation
,” Phys. Fluids
, Vol. 6
, pp. 199
–208
.19.
White, F. M., 1986, Fluid Mechanics, McGraw-Hill, New York, pp. 305–310.
20.
Wilcox
D. C.
1994
, “Simulation of Transition With a Two-Equation Turbulence Model
,” AIAA Journal
, Vol. 32
, No. 2
, pp. 247
–255
.
This content is only available via PDF.
Copyright © 1998
by The American Society of Mechanical Engineers
You do not currently have access to this content.
