scholarly journals Impact of Middle Turbinectomy on Airflow to the Olfactory Cleft: A Computational Fluid Dynamics Study

2018 ◽  
Vol 33 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Suhyla Alam ◽  
Chengyu Li ◽  
Kathryn H. Bradburn ◽  
Kai Zhao ◽  
Thomas S. Lee
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Middle Turbinate ◽  
Nasal Airway ◽  
Nasal Resistance ◽  
Nasal Airflow ◽  
Phenylethyl Alcohol ◽  
Olfactory Cleft ◽  
Airflow Field ◽  
The Impact

Background The impact of middle turbinate resection (MTR) on olfaction remains a point of debate in the current literature. Few studies have objectively evaluated olfactory cleft airflow following MTR; thus, the mechanism by which MTR may impact olfaction is poorly understood. It is not known whether the postsurgical changes in airway volume, flow, and resistance increase odorant transport or disrupt the patterns of normal airflow. Computational fluid dynamics can be used to study the nasal airway and predict responses to surgical intervention. Objective To evaluate the functional impact of MTR on nasal airflow, resistance, and olfaction. Methods Five maxillofacial computed tomography scans of patients without signs of significant sinusitis or nasal polyposis were used. Control models for each patient were compared to their corresponding model after virtual total MTR. For each model, nasal airway volume, nasal resistance, and air flow rate were determined. Odorant transport of 3 different odorants in the nasal cavity was simulated based on the computed steady airflow field. Results Total airflow significantly increased following bilateral MTR in all patient models ( P < .05). Consistent with our airflow results, we found a decrease in nasal resistance following MTR. MTR significantly increased area averaged flux to the olfactory cleft when compared to controls for phenylethyl alcohol (high-sorptive odorant). Results for carvone (medium sorptive) were similarly elevated. MTR impact on limonene, a low flux odorant, was equivocal. Conclusion MTR increases nasal airflow while decreasing the nasal resistance. Overall, olfactory flux increased for high sorptive (phenylethyl alcohol) and medium sorpitve (l-carvone) odorants. However, the significant variation observed in one of our models suggests that the effects of MTR on the nasal airflow and the resultant olfaction can vary between individuals based on individual anatomic differences.

scholarly journals Impact of Varying Types of Nasal Septal Deviation on Nasal Airflow Pattern and Warming Function: A Computational Fluid Dynamics Analysis

2019 ◽  
pp. 014556131987274 ◽  
Author(s):  
Lifeng Li ◽  
Hongrui Zang ◽  
Demin Han ◽  
Nyall R. London
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Septal Deviation ◽  
Maximal Velocity ◽  
Nasal Resistance ◽  
Nasal Airflow ◽  
Airflow Pattern ◽  
Computational Fluid Dynamics Analysis ◽  
Nasal Function ◽  
The Impact

Nasal septal deviations (NSD) have been categorized into 7 types. The effect of these different deviations on airflow pattern and warming function has not been fully investigated. The purpose of this study was to utilize a computational fluid dynamics approach to assess the impact of NSD of varying types on nasal airflow and warming function. Patients with each type of NSD were enrolled in the study, and a normal participant as the control. Using a computational fluid dynamics approach, modeling of nasal function was performed. Indices of nasal function including airflow redistribution, total nasal resistance, airflow velocity, and airflow temperature were determined. Among all types of NSD, the maximal velocity and total nasal resistance were markedly higher in type 4 and 7 deviations. The flow partition and velocity distribution were also altered in type 4 and 7 as well as type 2 and 6 deviations. Airflow in all categories of NSD was fully warmed to a similar degree. From a computational aerodynamics perspective, the type of septal deviation may contribute to altered airflow characteristics. However, warming function was similar between septal deviation types. Future studies will help to ascertain the functional importance of septal deviation types and the applicability of these computational studies.

scholarly journals Impact of a Concha Bullosa on Nasal Airflow Characteristics in the Setting of Nasal Septal Deviation: A Computational Fluid Dynamics Analysis

2020 ◽  
Vol 34 (4) ◽  
pp. 456-462
Author(s):  
Lifeng Li ◽  
Hongrui Zang ◽  
Demin Han ◽  
Murugappan Ramanathan ◽  
Ricardo L. Carrau ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Middle Turbinate ◽  
Volume Ratio ◽  
Control Group ◽  
Study Group ◽  
Nasal Resistance ◽  
Concha Bullosa ◽  
Nasal Airflow ◽  
Airflow Velocity ◽  
The Impact

Background A concha bullosa (CB) of the middle turbinate is frequently observed on the nondeviated side of patients with a nasal septal deviation (NSD). However, the impact of the CB on nasal airflow characteristics in patients with NSD has been incompletely defined. Objective The purpose of this study was to evaluate the impact of a CB in patients with NSD on nasal airflow characteristics using a computational fluid dynamics (CFD) approach. Methods Twenty patients with NSD and a unilateral CB of the middle turbinate on the nondeviated side (study group) were recruited. Another 20 patients with NSD without the formation of a CB (control group) were also enrolled. Using CFD, the maximal airflow velocity, nasal resistance, maximal wall shear stress, and minimal temperature in the bilateral nostrils of each group were assessed. Moreover, the volume of the nasal tract, surface area-to-volume ratio, and the total nasal resistance were compared between the study and control groups. Results In the study group, no significant differences of airflow dynamics between the bilateral nasal cavities were observed. In the control group, however, there were statistically significant differences for maximal airflow velocity, nasal resistance, maximal wall shear stress, and minimal airflow temperature between the bilateral nostrils. The surface area-to-volume ratio and total nasal resistance in the study group was significantly higher and the nasal volume was significantly decreased than that in the control group. Conclusion CB of the middle turbinate on the nondeviated side of patients with NSD rendered airflow characteristics more evenly distributed between the bilateral nostrils as assessed by CFD. From an aerodynamics perspective, a CB may represent a compensatory action to normalize airflow dynamics. However, a CB may also result in constriction of the ipsilateral nasal cavity.

An Overview of Computational Fluid Dynamics Preoperative Analysis of the Nasal Airway

2021 ◽  
Author(s):  
Rui Xavier ◽  
Dirk-Jan Menger ◽  
Henrique Cyrne de Carvalho ◽  
Jorge Spratley
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Surgical Techniques ◽  
Virtual Surgery ◽  
Nasal Airway ◽  
Cfd Analysis ◽  
Nasal Airflow ◽  
Nasal Breathing ◽  
Objective Measurements ◽  
Patient Reported

AbstractEvaluation of the nasal airway is crucial for every patient with symptoms of nasal obstruction as well as for every patient with other nasal symptoms. This assessment of the nasal airway comprises clinical examination together with imaging studies, with the correlation between findings of this evaluation and symptoms reported by the patient being based on the experience of the surgeon. Measuring nasal airway resistance or nasal airflow can provide additional data regarding the nasal airway, but the benefit of these objective measurements is limited due to their lack of correlation with patient-reported evaluation of nasal breathing. Computational fluid dynamics (CFD) has emerged as a valuable tool to assess the nasal airway, as it provides objective measurements that correlate with patient-reported evaluation of nasal breathing. CFD is able to evaluate nasal airflow and measure variables such as heat transfer or nasal wall shear stress, which seem to reflect the activity of the nasal trigeminal sensitive endings that provide sensation of nasal breathing. Furthermore, CFD has the unique capacity of making airway analysis of virtual surgery, predicting airflow changes after trial virtual modifications of the nasal airway. Thereby, CFD can assist the surgeon in deciding surgery and selecting the surgical techniques that better address the features of each specific nose. CFD has thus become a trend in nasal airflow assessment, providing reliable results that have been validated for analyzing airflow in the human nasal cavity. All these features make CFD analysis a mainstay in the armamentarium of the nasal surgeon. CFD analysis may become the gold standard for preoperative assessment of the nasal airway.

scholarly journals The impact of nasal adhesions on airflow and mucosal cooling - a computational fluid dynamics analysis

2021 ◽  
pp. 103719
Author(s):  
Praween Senanayake ◽  
Hana Salati ◽  
Eugene Wong ◽  
Kimberley Bradshaw ◽  
Yidan Shang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamics Analysis ◽  
Computational Fluid Dynamics Analysis ◽  
The Impact

scholarly journals The Protect Air Film of an Exterior Window

2021 ◽  
Author(s):  
Sanaz Dianat
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Glass Temperature ◽  
Experimental Procedure ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Air Film ◽  
The Impact

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed

scholarly journals The Protect Air Film of an Exterior Window

2021 ◽  
Author(s):  
Sanaz Dianat
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Glass Temperature ◽  
Experimental Procedure ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Air Film ◽  
The Impact

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed

scholarly journals Assessment of nasal resistance using computational fluid dynamics

2016 ◽  
Vol 2 (1) ◽  
pp. 617-621 ◽  
Author(s):  
Jan Osman ◽  
Friederike Großmann ◽  
Kay Brosien ◽  
Ulrich Kertzscher ◽  
Leonid Goubergrits ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gold Standard ◽  
Objective Assessment ◽  
Nasal Resistance ◽  
Nasal Breathing ◽  
Current Gold Standard ◽  
Flow Parameters

AbstractAnterior rhinomanometry is the current gold standard for the objective assessment of nasal breathing by determining the nasal resistance. However, computational fluid dynamics would allow spatially and temporally well- resolved investigation of additional flow parameters. In this study, measured values of nasal resistance are compared with measured values. An unclear discrepancy between the two methods was found, suggesting further investigation.

scholarly journals Computational Fluid Dynamics of Vascular Disease in Animal Models

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Andrea Acuna ◽  
Alycia G. Berman ◽  
Frederick W. Damen ◽  
Brett A. Meyers ◽  
Amelia R. Adelsperger ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Animal Models ◽  
Vascular Disease ◽  
Vascular Diseases ◽  
Cfd Modeling ◽  
Shear Stresses ◽  
Human Patient ◽  
Arteriovenous Fistulas ◽  
The Impact

Recent applications of computational fluid dynamics (CFD) applied to the cardiovascular system have demonstrated its power in investigating the impact of hemodynamics on disease initiation, progression, and treatment outcomes. Flow metrics such as pressure distributions, wall shear stresses (WSS), and blood velocity profiles can be quantified to provide insight into observed pathologies, assist with surgical planning, or even predict disease progression. While numerous studies have performed simulations on clinical human patient data, it often lacks prediagnosis information and can be subject to large intersubject variability, limiting the generalizability of findings. Thus, animal models are often used to identify and manipulate specific factors contributing to vascular disease because they provide a more controlled environment. In this review, we explore the use of CFD in animal models in recent studies to investigate the initiating mechanisms, progression, and intervention effects of various vascular diseases. The first section provides a brief overview of the CFD theory and tools that are commonly used to study blood flow. The following sections are separated by anatomical region, with the abdominal, thoracic, and cerebral areas specifically highlighted. We discuss the associated benefits and obstacles to performing CFD modeling in each location. Finally, we highlight animal CFD studies focusing on common surgical treatments, including arteriovenous fistulas (AVF) and pulmonary artery grafts. The studies included in this review demonstrate the value of combining CFD with animal imaging and should encourage further research to optimize and expand upon these techniques for the study of vascular disease.

scholarly journals Experimental and CFD Modelling: Impact of the Inlet Slug Flow on the Horizontal Gas–Liquid Separator

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Siong Lee ◽  
Thomas Choong ◽  
Luqman Abdullah ◽  
Mus’ab Abdul Razak ◽  
Zhen Ban
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Liquid Phase ◽  
Flow Pattern ◽  
Slug Flow ◽  
Cavity Formation ◽  
Cfd Modelling ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Liquid Separator

For a gas-liquid separator sizing, many engineers have neglected the flow pattern of incoming fluids. The impact of inlet slug flow which impeded onto the separator’s liquid phase will cause a separator fails to perform when sloshing happened in the separator. To date, the study on verifying the impact of inlet slug flow in a separator remains limited. In this paper, the impact of inlet momentum and inlet slug flow on the hydrodynamics in a separator for cases without an inlet device were investigated. The experimental and Computational Fluid Dynamics (CFD) results of cavity formation and sloshing occurrence in the separator in this study were compared. A User Defined Function (UDF) was used to describe the inlet slug flow at the separator inlet. Inlet slug flow occurred at inlet momentum from 200 to 1000 Pa, and sloshing occurred in the separator at 1000 Pa. Both experimental and simulated results showed similar phenomena.

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