Measurement of Cyclic Flows in Trachea Using PIV and Numerical simulation
Abstract
Inhalation of pharmaceutical aerosols is a convenient way to treat lung or even systemic diseases. For effective treatment it is very important to understand air flow characteristics within respiratory airways and determine deposition hot spots. In this paper the air flow in trachea was investigated by numerical simulations. To validate these results we carried out particle image velocimetry experiments and compared resulting velocity fields. Simplified geometry of respiratory airways from oral cavity to 4th generation of branching was employed. Air flow characteristics were analysed during sinusoidal breathing pattern for light activity conditions (period 4 s and tidal volume 1 l). The observed flow fields indicated that the flow in trachea is turbulent during the sinusoidal flow except phases of flow turnarounds. The flow was skewed to front side of the trachea during inspiration and had twin-peak profile during expiration because of the mixing from daughter branches. The methods were compared and good agreement was found. This validation of CFD simulation can result into its further usage in respiratory airflow studies.
Full text
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wned by the authors, published by EDP Sciences, 2015 / 0200 (2015) 201epjconf EPJ Web of Conferences , 0200 59 92 2 ! 6 6 Article available at http://www.epj-conferences.org or http://dx.doi.org/10.1051/epjconf/20159202006
$ 6$ 6 " ' '" &' 6 " " (" ( 6 "&'""'"$ 6 $6$(+-; " 5( ' 6 6 " "" $6$$ 0'('(9-(:$ 25B " +-; - ' ' 7 '""$ '$7$7"'"(6$6''6 " $ '.6" ( &' ($ "( 6$ " ' '('"'((&' 6 "" ' ' 9-(:" '"$6 ('$"9 "0"" : 7 "+-;" $6$ " ! 2 5( B$ '" $ 6 ' " " $ " &' 7 9-(:" "'( "'("25B$&'66 ""6' "' 6 "" ' 6 ' '" "(' "7 8' ' 7 '( E("E!E0 EA (E) E325BE/ + '25B$6"" ' " ' " 1 " (' ' 7$'4(6 ""$ ".'" " F"G1@ 9F6 H @ 4 0I:&85 66 0 6' ( 6 " "$'(''(' 6'( &( 6 7"$&85$'"(6 " (5('!@6(' ' "$6"1/4( 6 "$ '( $ " ( +. 6 ""'" ' , -./ 0112 020 ,0, *3* 7 $$ " " . " " 6 " $ ""( " " # '("67" 6 8++J /4 &' $'" '")"( ' 6 ( "$ $ &' ' 6 (" " 6 6 J 9J K : " ( +"('('$ ''6 "(' 444 &'6"'($ 9('$":",$"("F. 8 9,1F8: " 6 $" ' ( ,$" '( $6$ $(9!44440:=4> '$" 88& " => 6' " 6,$"6 " "$"'"6 6''7 2 6 " ' "$ " &' "$ " 6 " ' " $ 7 " 6 "" $ ? 6'' "$$ '"6 ݒሺݐሻൌܸ௧ήߨ ܵήܶήݏ݅݊൬ʹߨ ܶήݐ൰ሺ݉ݏ݁ܿିଵሻ 9: Y9W67W " $ ; ,$" " H$ 6 " " ' "'""" ,$" " 6 " ' !44 (' 5 "6' ܴ݁ൌݒήܦ ߥ 9 : EPJ Web of Conferences 02006-p.2
H' '"9": " ȣ $ H$ ? " ' 6 " ' "$ 5 "( ߙൌܮ ʹήට݊ ߥ 9 !: H' ' " 9": ?$ " &' 6 "" ?"$ ' H$ '=> $ % &' ( ' 6 7 " $ " ' -6 ( 6 " (' '"6''"940A*4 5 *.6: ' ' ' 7 "695..5:-(! "" ; 6 " '" $ ' " " & 7 ' 6'' 6 7 " &' H$ 3 (( ?"$6,$" '6 '(' ' ,$" (' 66''"6 ; 0A!AA!A !)04 3 *434 A03 3 B$ " ' '" " " " $"-(!-$$$ ""'" $"' ( B$ " 6" "( 6'' 6 $ " $ ' ' ( ( ." $( < &' 7 $ 6 '" ' ' 6 7( ' 6 "(' ' " '(''6"(7 B '6 '7 " ' B$ LA (' " 6 ' '6 -( A &' 6 " 6'' 6 " $ ""( ' $ ' '(' $ 7 $ 1 ' '('$$"( 6''('6"' ' ' ' '" (" ' $$ &' .(((6 6''(6'",$" &6. ' ' 6 6 " "( 7 '5"'' ' ' ' " 6 9 8"6'"($E+ $" EFM 2014 02006-p.3
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eb of Conferences 02006-p.4