CFD Modeling of Spray Atomization for a Nasal Spray Device

Abstract

The purpose of this work is to evaluate numerical modeling techniques for simulation of spray atomization from a nasal spray device to complement experimental measurements previously. In the past, spray breakup models have not been applied to nasal spray applications, but rather for high-pressure applications such as combustion, and industry and agricultural spraying. The parameters in breakup model were not optimized for this kind of low-pressure injection with small-scale atomizer. Thus, there is a need to tune the spray model constants of the linear instability sheet atomization (LISA) model and evaluate its performance for low-pressure applications such as those found in nasal spray devices. Some parameters that were evaluated include the dispersion angle and the liquid sheet constant that influences the droplet size distribution and dispersion. The simulation results were evaluated against experimental data that has been previously performed. It was found that the LISA model provided good comparisons when a dispersion angle of 3• and a liquid sheet constant of 1 were used. In addition, three scenarios were investigated: (i) influence of fluiddroplet coupling; (ii) increase in mass flow rate; and (iii) changing the orientation from downward spray to upward spray.

Measurements of Droplet Size Distribution and Analysis of Nasal Spray Atomization from Different Actuation Pressure

“…According to Fung et al, (26) fine droplets are transported and dispersed throughout the spray from the presence of turbulent eddies in the flow. These droplets quickly lose their momentum and become entrained in the flow field.…”

Detailed micro-particle deposition patterns in the human nasal cavity influenced by the breathing zone

“…Since then computational studies have investigated its anatomical form, airflow patterns, and fluid-particle interactions to gain a better understanding of: respiration function [7][8][9][10]; airconditioning [11,12]; and surgical implications [13][14][15][16][17]. When a secondary particle phase is introduced, inhaled particles coupled to the airflow field, allow studies of nasal drug delivery [18][19][20][21][22]; and inhalation toxicology [23][24][25] or general particle deposition studies [26,27]. The work by Wang et al [28] indicated deposition efficiency for 22 lm particles in the nasal cavity reached 100% for light breathing and revealed deposition hot spots for micron-particles.…”

Nasal sprayed particle deposition in a human nasal cavity under different inhalation conditions

“…Other computational studies include: Keeler et al [17] who investigated the influence of nasal airway geometry from different ethnic groups on spray particle deposition and found that white and Latin Americans had the least patent nasal cavity, although this was based on four models per ethnic group; Kiaee et al [18] that found particle diameter and particle injection speed, were the dominant parameters (other parameters were spray cone angle, spray release direction, and particle injection location) that influenced deposition in seven adult nasal airways; and Fung et al [19] performed CFD modelling to characterise the nasal spray atomization stage. Djupesland et al [20] showed a bi-directional nasal delivery concept reduced lung deposition by taking advantage of the posterior connection between the nasal passages persisting when the soft palate automatically closes during oral exhalation.…”