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ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

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temperature [5], and Wbl is the water flux that is calculated by equation (4). If Qlatent is<br />

positive, Qlatent represent condensation latent heat. If Qlatent is negative, Qlatent represent<br />

evaporation latent heat. Total of Heat flux represent equation (3).<br />

3.2 Nasal Cavity Wall Model for Humidity exchange<br />

Fig.2 Nasal Cavity Wall Model for Humidity exchange<br />

W bl = D bl<br />

W memb = D memb<br />

F ! F S<br />

! bl<br />

F S ! F O<br />

! memb<br />

Figure 2 illustrates nasal cavity wall model for humidity exchange. The humidity of<br />

nasal cavity air is adapted via mucus membrane. Wbl is defined by equation (4). Wbl<br />

represent water flux to the inhaled air from the surface of membrane. Wmemb is defined<br />

by equation (5). Wmemb represent water flux to the surface of membrane from the organ<br />

side, where F is water fraction in the inhaled air, FS is water fraction on the surface of<br />

membrane, FO is water fraction in the organ side, Dmemb is mass diffusive coefficient of<br />

the membrane and Dbl is mass diffusive coefficient of the boundary layer. Since water<br />

transfer to the airside from the organ side via the membrane and the boundary layer, the<br />

water flux Wmemb and Wbl should be equal according two-films theory. FS is obtained as<br />

shown in equation (6) by solving equation (4) and equation (5). FS is fixed to boundary<br />

condition for humidity exchange.<br />

!<br />

#<br />

"<br />

FS =<br />

!<br />

#<br />

"<br />

4. Calculation Condition<br />

Dmemb ! memb<br />

Dmemb ! memb<br />

4.1 Reconstruction of Nasal Cavity Geometry<br />

$<br />

&FO '<br />

%<br />

D ! $<br />

bl<br />

# &F<br />

" ! bl %<br />

$<br />

&+<br />

%<br />

D ! $<br />

bl<br />

# &<br />

" %<br />

Fig.3 Reconstructed Nasal Cavity Geometry<br />

! bl<br />

(4)<br />

(5)<br />

(6)

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