Test Data AC7-02: Difference between revisions
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The lung model was placed in an open liquid tank with a piston diaphragm pump attached to a linear actuator to achieve a quasi-stationary inspiratory flow. | The lung model was placed in an open liquid tank with a piston diaphragm pump attached to a linear actuator to achieve a quasi-stationary inspiratory flow. | ||
The stroke of the piston followed a cyclic triangular function with an adjustable falling constant slope and thus constant velocity to match different flow rates during inspiration. | The stroke of the piston followed a cyclic triangular function with an adjustable falling constant slope and thus constant velocity to match different flow rates during inspiration. | ||
The employed working fluid is a mixture of water/glycerine (43:57 mass ratio, <math> \rho=1150kg/m^3, \, \nu=8.4\cdot 10^{-6} m^2/s </math> at <math>20^oC </math>, | The employed working fluid is a mixture of water/glycerine (43:57 mass ratio, <math> \rho=1150kg/m^3, \, \nu=8.4\cdot 10^{-6} m^2/s </math> at <math>20^oC </math>), | ||
which exactly matches the refractive index of the silicone model. | which exactly matches the refractive index of the silicone model. | ||
Neutrally buoyant polyamide particles (<math >d_p = 50\mu m </math>) were used as tracer particles (Stokes number Stk ≈ 0.002). | Neutrally buoyant polyamide particles (<math >d_p = 50\mu m </math>) were used as tracer particles (Stokes number Stk ≈ 0.002). | ||
Revision as of 12:34, 17 May 2020
Airflow in the human upper airways
Application Challenge AC7-02 © copyright ERCOFTAC 2020
Test Data
Overview of Tests
PIV measurements were performed at six different planes within the lung replica (see Fig. 6). The first three planes were located within the inlet tube with the aim to determine the exact inlet conditions. Plane IV corresponds to the central plane of the oral cavity and the pharynx. Note that this plane is tilted by 2o from the exact vertical orientation. The larynx and the upper trachea were imaged by plane V, and plane VI covers the main bifurcation and bronchi. Both planes are vertical. For all of the measurement stations, the mean velocity and turbulent kinetic energy fields from the in-plane velocity components are determined (see section 4 and equations 8-11).
Description of experiment
The lung model was placed in an open liquid tank with a piston diaphragm pump attached to a linear actuator to achieve a quasi-stationary inspiratory flow. The stroke of the piston followed a cyclic triangular function with an adjustable falling constant slope and thus constant velocity to match different flow rates during inspiration. The employed working fluid is a mixture of water/glycerine (43:57 mass ratio, at ), which exactly matches the refractive index of the silicone model. Neutrally buoyant polyamide particles () were used as tracer particles (Stokes number Stk ≈ 0.002). Particle images were recorded using a CCD camera (pco.1600, PCO) with a resolution of 1600px x 1200px in double-frame mode. A total number of 688 image pairs were acquired for each measurement. Illumination was provided by a double-pulse Nd:YAG laser ( = 532nm, MinilitePIV, Continuum, 10 mJ per pulse). Images were evaluated by DaVis 8 (LaVision). The final grid size is 32 x 32px (planes I-III) and 16 x 16px (planes IV-VI), respectively, both with 50% overlap.
Boundary conditions
Measurement errors
Contributed by: P. Koullapisa, J. Muelab, O. Lehmkuhlc, F. Lizald, J. Jedelskyd, M. Jichad, T. Jankee, K. Bauere, M. Sommerfeldf, S. C. Kassinosa —
aDepartment of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
bHeat and Mass Transfer Technological Centre, Universitat Politècnica de Catalunya, Terrassa, Spain
cBarcelona Supercomputing center, Barcelona, Spain
dFaculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
eInstitute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Freiberg, Germany
fInstitute Process Engineering, Otto von Guericke University, Halle (Saale), Germany
© copyright ERCOFTAC 2020