Computational fluid dynamics: applications in pharmaceutical technology - Computer-Aided Applications in Pharmaceutical Technology - page 234

effects of forces on fl uid motion. With the evolution in computer
technology, a branch of fl uid dynamics called computational fl uid
dynamics (CFD) has become a powerful and cost-effective tool for
simulating real fl uid fl ow.
The explanations for many natural phenomena, such as river fl ows,
ocean waves, wind currents, functioning of the human body (e.g.
cardiovascular and pulmonary system), lie in the fi eld of fl uid mechanics.
Fluid mechanics has, above all, a great importance in development and
performance optimization of complex engineering systems, such as
airplanes, ships, cars (Fay, 1994).
Recent results have announced the importance and possible applications
of fl uid mechanics in the fi eld of biomedicine. For example, some of the
procedures used in treatment of blood vessel obstruction (e.g. stenting,
balloon angioplasty, in situ drug delivery for unclotting, bypass surgery,
etc.) have statistically signifi cant failure rates, which indicates a need for
a patient-specifi c approach and detailed study of fl uid dynamics before
and after intervention. The prediction and modeling of fl ows in vascular
and pulmonary systems on a patient-specifi c basis is still an obstacle, but
it is becoming more likely that CFD will fi nd its place in enhanced
diagnosis and planning of surgical procedures (Löhner et al., 2003). CFD
simulations may give valuable information regarding characteristics of
blood fl ow under complex fl ow conditions, as well as deformation
and fl ow of erythrocytes in microcirculation (Jafari et al., 2009). In
combination with medical imaging techniques, CFD might be a
powerful tool for patient-specifi c simulation of blood fl ow inside the
abdominal aorta bifurcation (Makris et al., 2011), or it might be used
to explain variable incidence of vascular dysfunction among
patients with surgically repaired coarctation of the aorta (Olivieri
et al., 2011). With future improvements in computing power, CFD is
expected to become a valuable tool in clinical practice, for diagnosis
and treatment of cerebral aneurysms (Wong and Poon, 2011a; Sforza
et al., 2012).
The knowledge and understanding of the movement of particles and
their deposition in the respiratory airways is important to ensure effective
treatment. CFD modeling may provide an insight into the mechanisms of
airfl ow and particle transport through the asymmetrically branched
airways structure (Calay et al., 2002). CFD has also been successfully
applied in the study of fl ow fi eld and micro- and nanoparticle deposition
in the human upper airway, from the nasal cavity to the end of the trachea
(Ghalati et al., 2012). Chronic obstructive pulmonary disease is
characterized by infl ammation that leads to narrowing and obstruction

￿

￿ ￿