Environmental Engineering Reference
In-Depth Information
Fig. 3 Dimensionless skin surface temperature for different perturbations
the temperature profiles developed. Curve A indicates that the effect of the metabolic
heat on the temperature is very small, hence, this value will be taken as reference for
the results reported. Curve B does not exceed the maximum temperature, however
aBi
4347 indicates some pathology such as cancer. In curve C , the trajectory
exceeds the maximum temperature causing thermal damage. Curves A ,B and C
include the perturbation to
>
0
.
ʸ f by placing a stochastic parameter; this has a damping
effect along the curve due to the perfused tissue. Figure 3 shows the effect of the
perturbation on the skin surface temperature. It is worth mentioning that when the
value of
ʻ
increases, the surface presents higher variations and this effect is damped
inside the tissue by the blood perfusion, according to Fig. 2 . In order to facilitate the
profile comparison, the seed used to generate the perturbation in this case was the
same. Lastly, the temperature distributions using a constant surface flux are depicted
in Fig. 4 . This situation occurs when the tissue is burned by a point contact with an
object. Case (1). The classical Fourier equation is compared ( De T
=
0) with the
relaxation equation for different values of De T and for a time
2. The results
show that with the increase of De T the relaxation effects are more likely to reach a
steady state. However, for short times and small scales an opposite effect is produced,
the tissue begins to raise its internal energy in a more controlled manner. Namely,
the temperature increases more slowly than the classical Fourier Case (2).
A comparison with Case (1) is exposed, including the stochastic effect in
˄ =
0
.
ʸ f ;
which results in a variation of the temperature distribution that increases as
˄
does.
For values of De T
>
0
.
0013, it can be seen that the temperature ranges between
[0.02
0.25] through the whole curve, as compared with the relaxation curves.
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