Complex Secondary Flow Research Articles

Is the mouse nose a miniature version of a rat nose? A computational comparative study

Background and objectiveAlthough the mouse is a widely used animal model in biomedical research, there are few published studies on its nasal aerodynamics, potentially due to its small size. It is not appropriate to assume that mice and rats' nasal structure and airflow characteristics are the same because the ratio of nasal surface area to nasal volume and body weight is much higher in a mouse than in a rat. The aim of this work is to use anatomically accurate image-based computational fluid dynamic modeling to quantitatively reveal the characteristics of mouse nasal airflow and mass transport that haven't been detailed before and find key differences to that of rat nose, which will deepen our understanding of the mouse's physiological functions. MethodsWe created an anatomically accurate 3D computational nasal model of a B6 mouse using postmortem high-resolution micro-CT scans and simulated the airflow distribution and odor transport patterns under restful breathing conditions. The deposition pattern of airborne particles was also simulated and validated against experimental data. In addition, we calculated the gas chromatograph efficiency of odor transport in the mouse employing the theoretical plate concept and compared it with previous studies involving cat and rat models. ResultsSimilar to the published rat model, respiratory and olfactory flow regimes are clearly separated in the mouse nasal cavity. A high-speed dorsal medial (DM) stream was observed, which enhances the delivery speed and efficiency of odor to the ethmoid (olfactory) recess (ER). The DM stream split into axial and secondary paths in the ER. However, the secondary flow in the mouse is less extensive than in the rat. The gas chromatograph efficiency calculations suggest that the rat may possess a moderately higher odorant transport efficiency than that of the mouse due to its more complex ethmoid recess structure and extensive secondary flow. However, the mouse's nasal structure seems to adapt better to varying airflow velocity. ConclusionsDue to the inherent structural disparities, the rat and mouse models exhibit moderate differences in airflow and mass transport patterns, potentially impacting their olfaction and other behavioral habits.

A Numerical Design Space Investigation of Low-Speed Axial Compressor Stages Using Single-Row and Tandem Bladings

Abstract The present article numerically investigates the design space of an axial, low-speed compressor stage using tandem and single aerofoil configurations. The investigated rotor and stator designs follow a coupled throughflow and blade-to-blade design approach and will yield quasi-3D designed compressor stages with either single-rotor single-stator or tandem-rotor tandem-stator configurations. In past studies, tandem aerofoil configurations have shown a potential for increasing stage working coefficients, while maintaining their efficiency compared to their single aerofoil reference configuration. However, it was also shown that tandem configurations are able to reduce efficiency due to an increase of secondary flow caused by the higher loading and introduction in the second aerofoil. Currently, there is no clear design guideline on when tandem aerofoil configurations should be preferred over single ones, and under which circumstances they should be avoided. To answer this question, the present article will attempt to create a “Smith chart” for tandem aerofoil stages and compare them to their single aerofoil counterparts. Originally intended for use with turbine stages, the Smith chart maps out the potential efficiencies of turbomachinery designs. It plots the working coefficient (Ψ) over the throughflow coefficient (φ), which gives a direct indication of the shape of velocity triangles in the stage. However, the Smith chart has been well investigated for single aerofoil stages, both numerically and experimentally, as well as for low- and high-speed applications, and this is not the case so far for tandem configurations. The current work presents a fast Q3D design and analysis procedure used on a low-speed axial compressor stage and will yield quasi-3D efficiencies for a large number of different design coefficients. The findings of this work will enable future research to identify preferred combinations of design coefficients for tandem aerofoil configurations, which can then be further analyzed in 3D investigations at a higher fidelity level.

An Active Phantom Cooling Concept for Turbine Endwall Cooling From Pressure-Surface Film Coolant Injection

Abstract Cooling of the endwall of a turbine vane should receive special attention due to its uniqueness of near-wall complex secondary flows and concomitant challenge of offering film-coverage for cooling the endwall pressure-side corner regions. The use of internal enhanced cooling at the endwall backside could be an option, but it increases manufacturing cost, adds weight to the component, causing excessive pressure losses in the secondary air system. Novel film cooling concepts are, therefore, required to provide effective cooling for these difficult-to-cool regions. This study proposes an active cooling concept effected by placing a row of film cooling holes on the vane pressure surface near the endwall with the intention of utilizing second-order cooling (or phantom cooling) from pressure-surface film-coolant injection to provide increased cooling effectiveness and enlarge coverage on the endwall. The effects of hole diameter, injection angle, and compound angle, as well as coolant injection rate are investigated. Detailed phantom cooling effectiveness over the endwall is documented using Pressure-Sensitive Paint (PSP). To provide a description of the flow physics driving the cooling process, computational modeling is carried out to document mixing of coolant with the freestream. Experiments show that significant cooling occurs in the endwall pressure-side corner and extends beyond the passage throat. Higher coolant injection rates and an optimized pressure-surface injection geometry maximize endwall phantom cooling. An effectiveness correlation for the active cooling is developed to provide a straightforward tool for designers to apply in turbine design.

Numerical investigation on film cooling and aerodynamic performance for gas turbine endwalls with upstream vane-type and cascade-type slots

To further improve the thermal efficiency of gas turbine, the turbine inlet temperature (TIT) increases up to 2000 K, leading to an extremely high heat load on the first-stage vane. Taking into consideration that there are complex endwall secondary flow and the passage vortices which have significant effect on the flow field and thermal behavior near the endwall, it is essential to study the aero-thermal characteristics of endwall and develop efficient endwall cooling approach. In this work, two novel upstream slot structures, referred to as the vane-type slot and cascade-type slot, are proposed, and a comprehensive numerical analysis is conducted to reveal their mechanism and superiority in improving the film cooling and aerodynamic performance of first-stage vane compared with the conventional slot structure. The results indicate that compared with the conventional rectangular straight slot, the coolant jets from two novel slots have a more significant inhibition effect on the development of the endwall secondary flow due to their lower outflow angle and thus higher momentum in streamwise direction, which contributes to reducing the strength of the endwall secondary flow. This is beneficial to provide a lower cascade aerodynamic loss and a higher film cooling effectiveness of the endwall near the suction side leading edge and the higher film cooling effectiveness along the trajectory of the horseshoe vortex on the more downstream region. Moreover, the vane-type slot provides the largest coolant coverage and cooling effectiveness of endwall and the lowest total pressure loss within slot and cascade aerodynamic loss, followed by the cascade-type slot and conventional slot.

A Numerical Test Rig for Turbomachinery Flows Based on Large Eddy Simulations With a High-Order Discontinuous Galerkin Scheme—Part III: Secondary Flow Effects

Abstract In this final paper of a three-part series, we apply the numerical test rig based on a high-order discontinuous Galerkin scheme to the MTU T161 low-pressure turbine with diverging end walls at off-design Reynolds number of 90,000, Mach number of 0.6, and inflow angle of 41 deg. The inflow end wall boundary layers are prescribed in accordance with the experiment. Validation of the setup is shown against recent numerical references and the corresponding experimental data. Additionally, we propose and conduct a purely numerical experiment with upstream bar wake generators at a Strouhal number of 1.25, which is well above what was possible in the experiment. We discuss the flow physics at midspan and in the end wall region and highlight the influence of the wakes from the upstream row on the complex secondary flow system using instantaneous flow visualization, phase averages, and modal decomposition techniques.

Flow and heat transfer performance of bionic heat transfer structures with hybrid triply periodic minimal surfaces

Efficient energy conversion technologies are essential for mitigating the environmental impact of industrial activities. The development and application of high-efficiency heat exchangers are key components in this endeavor. Heat exchangers based on triply periodic minimal surfaces (TPMS) are widely acknowledged for their exceptional thermal-hydraulic performance. However, current research mainly focuses on the design and optimization of heat exchangers with standard TPMS structures. In this study, a hybrid process is utilized to construct ten novel heat exchangers, followed by comprehensive investigations of their internal flow fields using three-dimensional numerical simulations. In order to establish a baseline, five standard TPMS structures are also introduced as reference cases. The results reveal that complex secondary flow distributions and velocity variations are critical factors influencing the thermal-hydraulic performance. Moreover, the influence of different standard TPMS cells on the flow and heat transfer characteristics varies during the hybridization process. Specifically, the inclusion of the Schwarz cell generally leads to an improvement in heat transfer, while the presence of the Lindinoid cell may result in a deterioration of heat transfer. The Diamond and Lindinoid cells have an adverse impact on the flow characteristics, while the Gyroid and Neovius cells enhance the flow characteristics. To evaluate the overall thermal-hydraulic performance of different channels, a comprehensive performance assessment is introduced. The Diamond channel and the Gyroid-Neovius channel show superior overall performance in their respective Reynolds number regions, with the former exhibiting better flow characteristics and the latter has outstanding heat transfer performance.

Secondary flow and loss mechanisms of variable stator vanes in an annular cascade

Axial compressors with variable stator vanes require annular gaps and radial gaps from the endwalls for smooth adjustment, which induces complex secondary flows such as the penny leakage vortex and tip leakage vortex, leading to a negative impact on the aerodynamic performance. To better understand these mechanisms, numerical investigations were conducted on four different clearance configurations. The results show that the penny leakage vortex moves toward the suction side under the transverse pressure gradient and mixes with the hub corner stall vortex. This causes the corner separation to be further developed, leading to an increase in total pressure loss by 13.6%. However, the tip clearance leakage flow could reduce the transverse pressure gradient, which prevents penny leakage vortex from mixing with low-energy fluid in the corner region. Moreover, the hub corner stall vortex is also replaced by the tip leakage vortex, which effectively suppresses the range of corner separation. Under the comprehensive effects of the penny leakage vortex and the tip leakage vortex, the total pressure loss coefficient is increased only by 7.6%. Therefore, the mixing effect between the penny leakage vortex and low-energy fluid in the corner separation is the main reason for higher loss production of the cascade, and these findings provide theoretical support for the future application of flow control technology to reduce secondary flow loss.

Numerical study on the integration of supersonic turbine guide vanes and three-dimensional hydrogen/air rotating detonation combustor

Hydrogen/air rotating detonation turbine engine is expected to become a new generation of aerospace power plant because of its compact structure, high cycle thermal efficiency, and superior thrust performance. It can also reduce fuel consumption, save energy, and reduce carbon emissions. However, the highly unsteady oscillation characteristics of the outlet flow of the rotating detonation combustor make it difficult to integrate the supersonic turbine with the rotating detonation combustor. In this paper, the supersonic turbine guide vanes are designed by the method of characteristics and Bessel parameterization and are integrated with three-dimensional hydrogen/air rotating detonation combustors for numerical studies. The effects of aligned mode and misaligned mode on the coupling of supersonic turbine guide vanes and rotating detonation combustor are discussed carefully. The results show that the supersonic turbine guide vanes can make the rotating detonation wave change from a single-wave mode to a double-wave alternating strength and weak propagation mode. It can effectively suppress the oscillation of the combustion chamber outlet airflow. In the aligned mode, the peak pressure at the outlet of the supersonic turbine is about 70% lower than that at the cascade inlet, the pressure oscillation amplitude is reduced by 93.33%, and the temperature amplitude is reduced by 23.81%; the average total pressure loss coefficient of the cascade is 11.63%. In the misaligned mode, compared with the cascade inlet, the peak value of the pressure signal at the cascade outlet decreases by about 50%, while the pressure oscillation amplitude decreases by about 33.33%, and the temperature oscillation amplitude decreases by 11.11%; the average total pressure loss coefficient of the cascade is 4.83%. The supersonic turbine guide vanes have a better suppression effect on the oscillation signal in the aligned mode, but the relative total pressure loss is relatively large. This is because that the oblique shock wave, channel shock wave, and supersonic turbine guide vanes interact to generate more complex wave system and secondary flow in the aligned mode. These features provide important reference information for the coupling of supersonic turbines and rotating detonation combustors.

Heat Transfer Enhancement of Regenerative Cooling Channel with Pyramid Lattice Sandwich Structures

To meet the requirements of high heat transfer efficiency and light weight, the pyramid lattice structures are applied to the regenerative cooling design of scramjets. This study numerically investigates heat transfer and fluid flow characteristics of kerosene in a regenerative channel with pyramid lattice sandwich structures. At the same porosity, the maximum wall temperature of the pyramid lattice sandwich regenerative cooling channel decreases by 30%. With increased porosity, the cooling capacity of the pyramid regenerative cooling channel decreases gradually. The numerical results show that a complex secondary flow appears in the flow field in the pyramid lattice structures. In the downstream region of each strut, a spiral vortex is formed which accelerates the flow velocity approaching the wall with heat transfer enhancement. Because of the disturbing effect of the strut, a high turbulent kinetic energy region is formed in the upstream region of each strut and the heat transfer is enhanced. In general, the local heat transfer in the upstream region of the pyramid strut is better than that in the downstream region. For pyramid lattice structures, the cooling structures with high convective heat transfer and relatively low pressure drop can be obtained by optimization of the design parameters.

Experimental Studies on the Influence of Negatively Buoyant Jets on Flow Distribution in a 135-Degree Open Channel Bend

The present paper aims to investigate the evolution of velocity fields as well as secondary flows in an open channel bend under the influence of negatively buoyant jets. A 135-degree open channel bend was used for experiments, and the jet nozzle was located along the outer bank in the straight section upstream of the bend. Efforts were made to specify the flow structures with high precision measurements of three-dimensional velocities by means of a three-dimensional PIV (Particle Image Velocimetry) technology. The experimental results show that the jets comparatively affect the flow structure at the beginning and exit of the flow in a bend. Although the jets had little effect on the maximum streamwise velocity, complex secondary flow patterns and properties were found to be influenced due to the occurrence of the negatively buoyant jets in the bend.

Improved mass transfer performance of membrane units in a toroidal helical pipe—Reduction of concentration polarization by secondary flows

We evaluate a Toroidal Helical Pipe (THP) for the extent of process intensification that it can offer over an equivalent length of straight pipe by providing continuous curvature changes resulting in complex secondary flows in a compact space. The present study is a radical departure from traditional curved and helical tubes with constant curvatures as they often lead to a fully-developed state. The THP results in a continuously varying curvature. Here we examine the application of THP for membrane transport, where reducing the concentration polarization is a challenge. We build the geometry from a 3d space curve represented by C(t;R,r,n)=[(R+r·cosnt)·cost,(R+r·cosnt)·sint,r·sinnt], where R is the radius of the torus, r is the radius of the pipe, and n is the number of turns of the helical pipe around the torus. Although this enables a design optimization study over the geometric parameter space (R,r,n), we restrict our study to the following values C(t;5,1.2,7).The computational model is used to study solutions for a Reynolds number of up to Re=100 and a Peclet number of Pe=6×104. We demonstrate a significant reduction in the concentration polarization aided by the secondary flows with increasing Re. The permeate flow increased by 33% at Re=100.

Experimental Study of the Endwall Heat Transfer of a Transonic Nozzle Guide Vane With Upstream Jet Purge Cooling Part 1—Effect of Density Ratio

Abstract Nozzle guide vane (NGV) platforms often use complex cooling schemes to mitigate the ever-increasing thermal loads on endwall. Understanding the effect of advanced cooling schemes amid the highly complex three-dimensional secondary flow is vital to engine efficiency and durability. This study analyzes, experimentally and numerically, and describes the effect of coolant to mainstream blowing ratio, momentum ratio, and density ratio (DR) for a typical axisymmetric converging nozzle guide vane platform with an upstream doublet staggered, steep-injection, cylindrical hole purge cooling scheme. Nominal flow conditions were engine-representative and as follows: Maexit = 0.85, Reexit,Cax = 1.5 × 106 and an inlet large-scale freestream turbulence intensity of 16%. Two blowing ratios were investigated, each corresponding to the design condition and its upper extrema at M = 2.5 and 3.5, respectively. For each blowing ratio, the coolant to mainstream density ratio was varied between DR = 1.2, representing typical experimental neglect of coolant density, and DR = 1.95, representative of typical engine conditions. The results show that with a fixed coolant-to-mainstream blowing ratio, the density ratio plays a vital role in the coolant-mainstream mixing and the interaction between coolant and horseshoe vortex (HSV) near the vane leading edge. A higher density ratio leads to a better coolant coverage immediately downstream of the cooling holes but exposes the in-passage endwall near the pressure side. It also causes the in-passage coolant coverage to decay at a higher rate in the flow direction. From the results gathered, both density ratio and blowing ratio should be considered for accurate testing, analysis, and prediction of purge jet cooling scheme performance.

Unsteady simulation of flow and heat transfer in a transonic turbine stage under non-uniform inlet conditions

In modern aero-engines, the temperature non-uniformity (hot-streak) caused by the combustors and secondary flows caused by the rotor blades have a considerable impact on the aerothermal performances of the high pressure (HP) turbine. In this study, two idealized hot-streaks (radial and rounded) from literature and one engine representative hot-streak (distorted) were evaluated within a HP turbine stage using unsteady numerical simulation. The results were analyzed and discussed and they include, the stage performance, unsteady flow visualization, unsteady hot-streak transport, secondary flows/hot-streak interaction and blades thermal loading. It was found that the rotor passage had various complex secondary flows and the boundary layer on its surface undergone several transitions. The hot-streak transport and its contact with vane and rotor blades differed from one case to another. The secondary flows had a remarkable impact on the rotor exit temperature. They induced wavy shapes and corrugations of temperature gradients near the endwalls. All hot-streaks were completely deformed and distorted across the turbine stage. The rotor surfaces suffered from hot temperatures under radial and distorted hot-streaks compared with rounded hot-streak. Very high levels of the heat transfer were generated on the rotor suction side near the endwalls due to the vortices.

Analysis of unsteady flow in compressor cascade based on modal POD methods

There are complex secondary flow structures in the compressor cascade passage, which seriously suppresses the performance of the compressor. The flow structures are highly unstable, especially for highly loaded compressor cascades. The reduced-order model based on the modal decomposition method can capture the main characteristics of the flow field and offer a reference for the application of unsteady flow control methods. In this study, the POD methods are used to analyze the flow in a high-speed compressor cascade. The methods can extract the mode that reflects the main energy of the flow field. Both the design and off-design conditions are analyzed. The decomposition methods can obtain the global energy, time coefficient and spatial characteristics of the flow field. The result showed that the flow field of the cascade has high steadiness and regularity. The zeroth POD mode under design conditions occupies over 99% of the energy of the flow field. The fluctuation velocity of off-design conditions is larger. The first five POD modes can contain over 90% of the energy of the fluctuation velocity field.

A Computational Study on Fluid Flow and Heat Transfer Through a Rotating Curved Duct with Rectangular Cross Section

The understanding of fluid flow and heat transfer (HT) through a rotating curved duct (RCD) is important for different engineering applications. The available literature improved the understanding of the fluid flow and HT through a large-curvature rotating duct. However, the comprehensive knowledge of fluid flow and HT through an RCD with small curvature is little known. This numerical study aims to perform fluid flow characterization and HT through an RCD with curvature ratio 0.001. The spectral based numerical approach investigates the effects of rotation on fluid flow and HT for the Taylor number −1000≤Tr≤1500. A constant pressure gradient force, the Dean number Dn = 100, and a constant buoyancy force parameter, the Grashof number Gr = 500 are used for the numerical simulation. Fortran code is developed for the numerical computations and Tecplot software is used for the post-processing purpose. The numerical study investigates steady solutions and a structure of two-branches of steady solutions is obtained for positive rotation. The transient solution reports the transitional flow patterns and HT through the rotating duct, and two- to four-vortex solutions are observed. In case of negative rotation, time-dependent solutions show that the Coriolis force exhibits an opposite effect to that of the curvature so that the flow characteristics exhibit various flow instabilities. The numerical result shows that convective HT is increased with the increase of rotation and highly complex secondary flow patterns influence the overall HT from the heated wall to the fluid. To validate the numerical results, a comparison with the experimental data is provided, which shows that a good agreement is attained between the numerical and experimental investigations.

Unsteady Simulation of a Transonic Turbine Stage with Focus on Turbulence Prediction

The flow in a transonic turbine stage still poses a high challenge for the correct prediction of turbulence using an eddy viscosity model. Therefore, an unsteady RANS simulation with the k-ω SST model, based on a preceding study of turbulence inlet conditions, was performed to see if this can improve the quality of the flow and turbulence prediction of an experimentally investigated turbine flow. Unsteady Q3D results showed that none of the different turbulence boundary conditions could predict the free-stream turbulence level and the maximum values correctly. Luckily, the influence of the boundary conditions on the velocity field proved to be small. The qualitative prediction of the complex secondary flows is good, but there is lacking agreement in the prediction of turbulence generation and destruction.

Flow and heat transfer analysis of lead–bismuth eutectic flowing in a tube under rolling conditions

The investigation of flow and heat transfer of lead–bismuth eutectic (LBE) under rolling conditions is vital to the application of LBE cooled reactor in offshore engineering. In this paper, mature numerical method for modelling low Prandtl number liquid metal is used for LBE flow in a vertical tube under rolling conditions. Reynolds stress turbulent model is chosen to consider the complex secondary flow caused by additional force. It is found that the transverse additional force is the main reason accounting for the enhancement of heat transfer and secondary flow. The transient maximum heat transfer ability can be enlarged by 18% under condition of rolling angle of 30° and period of 8 s. And 10 times transverse additional force caused by rolling angle of 30° and period of 8 s is enough to change the flow resistance characteristic of LBE. Comparisons with water coolant indicate that the intensity of radial secondary flow play an important role in determining the heat transfer characteristic of fluid under rolling conditions. The high density and low Prandtl number also make the features of LBE under rolling conditions different from those of water. The empirical correlations used in system code now could not predict the flow and heat transfer of LBE under rolling conditions. Special attention should be paid to safety design criteria of the off-shore LBE cooled reactor. This paper may contribute to the thermal–hydraulic design of off-shore liquid metal cooled reactors.

Aero-Thermal Aspects of Film Cooled Nozzle Guide Vane Endwall—Part 1: Aerodynamics

Abstract The first-stage turbine of a modern gas turbine is subjected to high thermal loads which lead to a need for aggressive cooling schemes to protect its components from melting. Endwalls are particularly challenging to cool due to the complex system of secondary flows near them that wash the protective film coolants into the mainstream. This paper shows that without including combustor cooling, the complex secondary flow physics is not representative of modern engines. Aggressive injection of all cooling flows upstream of the passage is expected to interact and change passage aerodynamics and, subsequently, mixing and transport of coolants. This study describes, experimentally, the aero-thermal interaction of cooling flows near the endwall of a first-stage nozzle guide vane passage. The test section involves an engine-representative combustor–turbine interface geometry, combustor coolant flow, and endwall film cooling flow injected upstream of a linear cascade. The approach flow conditions represent flow exiting a cooled, low-NOx combustor. This first part of this two-part study aims to understand the complex aerodynamics near the endwall through detailed measurements of passage three-dimensional velocity fields with and without endwall film cooling. The aerodynamic measurements reveal a dominant vortex in the passage, named here as the Impingement Vortex, that opposes the passage vortex formed at the airfoil leading edge plane. This Impingement Vortex completely changes our description of flow over a modern film cooled endwall.

Turbulent flow structure and heat transfer mechanisms over surface vortex structures of micro V-shaped ribs and dimples

Turbulent flow and heat transfer characteristics in the channels with surface vortex structures of micro V-shaped ribs, dimples, and their hybrid structures have been investigated by carrying out delayed detached eddy simulations (DDES) at the Reynolds number of 50,500. It is found that, for the micro V-shaped rib, lower turbulent mixing is produced behind the leeward rib region, while the stronger longitudinal vortex pairs induced by the V-shaped ribs enhance the convective transport of heat. For the dimple, the shed vortices and the shear-layer vortices increase the near-wall turbulent mixing. The complex secondary flows induced by the flow separation, attachment and ejection increase the convective transport of heat. However, the flow separation produces a dead-air zone limiting the further increase of heat transfer enhancement. For the micro V-shaped rib-dimple hybrid structure, the strong downwash flow induced by the micro V rib breaks the recirculation zone inside the downstream dimple and the dimple here works as a vortex amplifier, which produces much stronger longitudinal vortex pairs. This process enhances both the turbulent mixing and convective transport of heat. Therefore, the micro V-shaped rib-dimple hybrid structure provides even more pronounced heat transfer enhancement.

Aerosol deposition and airflow dynamics in healthy and asthmatic human airways during inhalation

Inhalation of aerosols such as pharmaceutical aerosols or virus aerosol uptake is of great concern to the human population. To elucidate the underlying aerosol dynamics, the deposition fractions (DFs) of aerosols in healthy and asthmatic human airways of generations 13–15 are predicted. The Navier-stokes equations governing the gaseous phase and the discrete phase model for particles’ motion are solved using numerical methods. The main forces responsible for deposition are inertial impaction forces and complex secondary flow velocities. The curvatures and sinusoidal folds in the asthmatic geometry lead to the formation of complex secondary flows and hence higher DFs. The intensities of complex secondary flows are strongest at the generations affected by asthma. The DF in the healthy airways is 0%, and it ranges from 1.69% to 52.93% in the asthmatic ones. From this study, the effects of the pharmaceutical aerosol particle diameters in the treatment of asthma patients can be established, which is conducive to inhibiting the inflammation of asthma airways. Furthermore, with the recent development of COVID-19 which causes pneumonia, the predicted physics and effective simulation methods of bioaerosols delivery to asthma patients are vital to prevent the exacerbation of the chronic ailment and the epidemic.