On the assumption of steadiness of nasal cavity flow.

The unsteady flow through a model of the human nasal cavity is analyzed at a Strouhal number of Sr=0.791 for the complete respiration cycle. A comparison of the essential flow structures in the model geometry and a real nasal cavity shows the relevance of the model data. The analysis of the steady and unsteady solutions indicate that at Reynolds numbers Re> or =1500 the differences of the solutions of the unsteady and steady flow field can be neglected. To be more precise, the comparison of the total pressure loss distribution as a function of mass flux for the steady state and unsteady solutions shows the major differences to occur at increasing mass flux. At transition from inspiration to expiration the unsteady results differ the most from the steady state solutions. At high mass fluxes the total pressure loss of the nasal cavity flow almost matches that of the steady state solutions. The comparison with rhinomanometry measurements confirms the present numerical findings.

[1]  Gerhard Rettinger,et al.  Numerical simulation of intranasal air flow and temperature after resection of the turbinates. , 2005, Rhinology.

[2]  Toshio Nakayama,et al.  Visualization of flow resistance in physiological nasal respiration: analysis of velocity and vorticities using numerical simulation. , 2006, Archives of otolaryngology--head & neck surgery.

[3]  David Elad,et al.  Physical stresses at the air-wall interface of the human nasal cavity during breathing. , 2006, Journal of applied physiology.

[4]  J. Bonet,et al.  An alternating digital tree (ADT) algorithm for 3D geometric searching and intersection problems , 1991 .

[5]  H Masing,et al.  [Experimental studies on the flow in nose models]. , 1967, Archiv fur klinische und experimentelle Ohren- Nasen- und Kehlkopfheilkunde.

[6]  David Elad,et al.  Air-conditioning in the human nasal cavity , 2008, Respiratory Physiology & Neurobiology.

[7]  R. C. Schroter,et al.  Transport Phenomena in the Human Nasal Cavity: A Computational Model , 1998, Annals of Biomedical Engineering.

[8]  S. Shin,et al.  Nasal Airflow during Respiratory Cycle , 2006, American journal of rhinology.

[9]  Christoph Brücker,et al.  EXPERIMENTAL STUDY OF VELOCITY FIELDS IN A MODEL OF HUMAN NASAL CAVITY BY DPIV , 1999, Proceeding of First Symposium on Turbulence and Shear Flow Phenomena.

[10]  R. C. Schroter,et al.  Mechanics of airflow in the human nasal airways , 2008, Respiratory Physiology & Neurobiology.

[11]  C Kleinstreuer,et al.  Laminar airflow and nanoparticle or vapor deposition in a human nasal cavity model. , 2006, Journal of biomechanical engineering.

[12]  Wolfgang Schröder,et al.  Numerical investigation of the three-dimensional flow in a human lung model. , 2008, Journal of biomechanics.

[13]  W. Schröder,et al.  Numerical simulation of the interaction of wingtip vortices and engine jets in the near field , 2000 .

[14]  David Elad,et al.  The Air-Conditioning Capacity of the Human Nose , 2005, Annals of Biomedical Engineering.

[15]  T. Matsuzawa,et al.  Flow mechanisms in the human olfactory groove: numerical simulation of nasal physiological respiration during inspiration, expiration, and sniffing. , 2009, Archives of otolaryngology--head & neck surgery.

[16]  H. Chang,et al.  Correlations between flow resistance and geometry in a model of the human nose. , 1993, Journal of applied physiology.

[17]  Wolfgang Schröder,et al.  Investigation of the impact of the geometry on the nose flow , 2006 .