Atomized Droplets Research Articles

Determining the optimal oxidation temperature of non-isothermal liquid fuels injections using modeling based on statistical droplet distribution

Single-hole injections of liquid hydrocarbon fuels (isooctane and dodecane) under high turbulence have been investigated using direct numerical simulation based on the statistical model considering the droplets’ atomization, distribution, and combustion. The study objects are the heat and mass transfer processes during atomization and combustion of liquid fuels injections within the combustion chambers of thermal engines. The temperature and carbon dioxide concentration distributions of the fuel-air mixture, the distributions of the droplets, their velocities, and the Sauter mean radius within the isooctane and dodecane oxidation in the engine’s combustion space were obtained. An investigation of the oxidizer’s initial temperature influence on the droplets’ atomization and combustion processes showed that the optimal temperature for both fuels is 900 K. The obtained modeling results were confirmed in good agreement with theoretical and experimental data. Thanks to the integrated use of approaches from statistical theory, numerical algorithms and 3D computer modeling techniques, the results obtained are distinguished by high accuracy, efficiency in reducing computational resources, scientific novelty in the type of droplet atomization and suitability for practical application for technological solutions not only for single-hole, but also for multi-hole injections of liquid fuels and studying the jet-to-jet interaction phenomena. The obtained research results can be applied in miscellaneous internal combustion engines development with different atomization types, which will allow us to contemporaneously settle the concerns of streamlining the combustion process, improving the completeness of fuel combustion and reducing emissions of harmful substances

Enhancing the Proportion of Sub-5 μm Atomized Droplet Size in Medical Air-Compression Nebulizer

Medical air-compression nebulizers deliver atomized medication to the lungs, providing rapid and painless treatment for respiratory diseases. However, the size of most atomized droplets is around 10 μm, limiting drug deposition in the lower airways and alveoli, with increasing the proportion of sub-5 μm droplets remaining challenging. In this work, finite element analysis was employed to model the effects of gas flow rate, liquid channel width, and broken baffle structure on droplet size distribution, aiming to optimize structure symmetrical parameters and operating conditions. A novel compression atomizer was developed and experimentally evaluated, incorporating an improved symmetrical structure for the crushing baffle. Following this modification, the proportion of sub-5 μm droplets increased from 54.6% to 59.25%, representing a 4.65% enhancement in the generation of sub-5 μm droplets. The effects of gas flow rate and liquid concentration on droplet size distribution were systematically investigated to further optimize the atomization performance. The results demonstrated a significant increase in the proportion of sub-5 μm droplets, thereby enhancing drug delivery efficiency to the lower respiratory tract and improving treatment efficacy for respiratory diseases.

Investigation of Atomized Droplet Characteristics and Heat Transfer Performance in Minimum Quantity Lubrication Cutting Technology

ABSTRACTMinimum quantity lubrication (MQL) cutting technology is ecologically friendly and efficient in terms of cooling and lubrication. It has be.en widely used in recent years. The atomization effect of the MQL system was characterized by the average diameter of atomized droplets in this study. Second, the MQL heat transfer experimental platform was built, and the cooling experiments were carried out under different MQL parameters. The heat flux density is linearly related to the heat source temperature under steady‐state conditions, and the nozzle target distance has the greatest influence on the cooling effectiveness. The flow state of the lubricating oil is liquid film flow when the heat source temperature is lower than 120°C. The flow state of the lubricating oil is ditch flow when the heat source temperature is higher than 180°C. The average droplet diameter decreased by 43.7% when the pressure was 0.4 MPa compared with 0.2 MPa. An increase in gas supply pressure can improve the cooling effect of MQL. With the increase in flow rate, the average droplet diameter and steady‐state heat flux do not change significantly. At 270°C, the steady‐state heat flux at a flow rate of 90 mL/h was only 2.99% lower than that at 18 mL/h. The average droplet diameter is the smallest, and the cooling effect is the best when the nozzle diameter is 1.5 mm. The heat transfer effect is the best when the nozzle distance is 20 mm at different temperatures. When the nozzle distance is between 20 and 40 mm, the heat transfer capacity of MQL is the most stable. The heat transfer performance of MQL is helpful to improving the efficiency and quality of cutting, and promoting the implementation of a green manufacturing and sustainable development strategy.

Experimental study on the effect of nozzle configurations on snow quality for outdoor snow-makers

In regions with unfavorable climatic conditions and insufficient natural snowfall, skiing development depends significantly on the support of outdoor snow-makers. The atomized droplets produced by the swirl nozzle of the snow-maker collide with the crystal nucleus produced by the air-assisted atomizer to generate snowflakes. The effects of various configurations of swirl nozzles on snowmaking efficiency and snow quality are notably significant. This study investigates the influence of nozzle number, nozzle diameter, and ambient temperature on snowmaking performance through an outdoor snowmaking experiment. The results indicate that an appropriate nozzle configuration (number and diameter) significantly enhances snow quality. The spatial uniformity of snow density is significantly enhanced when utilizing 24 nozzles with a diameter of 1.9 mm and 72 mixed-diameter nozzles. With a nozzle diameter of 1.7 mm, the snow production of 48 and 80 nozzles is comparable; however, the water consumption of 48 nozzles is lower. Furthermore, at low temperatures, the artificial snow produced by the mixed-diameter nozzles exhibits snow quality characteristics comparable to those produced at high temperatures. Nevertheless, snow production is lower than that of the single-diameter nozzle configuration. Simultaneously, the density of the artificial snow produced at high temperatures is generally greater than that produced at low temperatures. Experimental measurements of the grain size of the artificial snow are concentrated between 0.15 and 0.55 mm. This study provides a basis for regulating snow quality in ski resorts. Additionally, it offers guidance on the design and structuring of efficient snow-makers.

Effects of structural parameters of pressure-swirl nozzle on atomization and dust removal characteristics.

To further improve the dust removal efficiency of water spray, the influence of key structure parameters of nozzle on atomization characteristic (droplet size, atomization angle, flow rate, effective spray distance, wind disturbance resistance) was studied. The results showed that the nozzle had good atomization performance when the outlet diameter was 1.5mm. The internal structure of the nozzle had an obvious influence on the atomization characteristics. The shrinkage angle had a prominent effect on the droplet size and atomization angle. When the shrinkage angle was increased from 60 to 120°, the droplet size and atomization angle were improved by 29.2% and 45.5%, respectively, while the increased shrinkage angle from 120 to 150° only improved by 9.1% and 4.2%, respectively. In addition, the diameter of the center hole had a strong correlation with the effective spray distance. When the diameter of the center hole increased from 1 to 2mm, the effective spray distance increased by 60.9% (to 7.4m) at the pressure of 4MPa, while the effective spray distance without change increased when the diameter of the center hole increased from 2 to 2.5mm. It was determined that the nozzle with the outlet aperture of 1.5mm, the shrinkage angle of 120°, and the diameter of the center hole of 2mm had good atomization and dust control characteristics. Additionally, it was verified that the optimized nozzle had a substantial improvement in controlling respirable dust, and the dust removal efficiencies for PM2.5 and PM5 were increased by 14.29% and 16.52%, respectively, compared to the original nozzle. This study provided guidance for choosing the nozzle of hydraulic support to form the effective dust control spray.

Atomization by Acoustic Levitation Facilitates Contactless Microdroplet Reactions.

Microdroplet chemistry is now well-known to be able to remarkably accelerate otherwise slow reactions and trigger otherwise impossible reactions. The uniqueness of the microdroplet is attributable to either the air-water interface or solid-liquid interface, depending on the medium that the microdroplet is in contact with. To date, the importance of the solid-liquid interface might have been confirmed, but the contribution from the air-water interface seems to be elusive due to the lack of method for generating contactless microdroplets. In this study, we used a droplet atomization method with acoustic levitation. Upon manipulation of the acoustic field, the levitated parent droplet can be further atomized into progeny microdroplets. With this method, only the air-water interface was present, and a large variety of reactions were successfully tested. We anticipate that this study can be an advance toward the understanding of the air-water interfacial processes of microdroplet chemistry.

Mean Droplet Size Prediction of Twin Swirl Airblast Nozzle at Elevated Operating Conditions

This study introduces a novel predictive model for atomization droplet size, developed using comprehensive data collected under elevated temperature and pressure conditions using a twin swirl airblast nozzle. The model, grounded in flow instability theory, has been meticulously parameterized using the Particle Swarm Optimization (PSO) algorithm. Through rigorous analysis, including analysis of variance (ANOVA), the model has demonstrated robust reliability and precision, with a maximum relative error of 19.3% and an average relative error of 6.8%. Compared to the classical atomization model by Rizkalla and Lefebvre, this model leverages theoretical insights and incorporates a range of interacting variables, enhancing its applicability and accuracy. Spearman correlation analysis reveals that air pressure and the air pressure drop ratio significantly negatively impact droplet size, whereas the fuel–air ratio (FAR) shows a positive correlation. Experimental validation at ambient conditions shows that the model is applicable with a reliability threshold of We1/Re1 ≥ 0.13 and highlights the predominance of the pressure swirl mechanism over aerodynamic atomization at higher fuel flow rates (q > 1.25 kg/h). This research effectively bridges theoretical and practical perspectives, offering critical insights for the optimization of airblast nozzle design.

Mixing Enhancement Mechanism of Liquid Jet in Supersonic Crossflow with Gas Throttling

Numerical and experimental studies were conducted to uncover the physical aspects of a liquid jet injected into a supersonic crossflow with gas throttling systematically. The results were obtained with the inflow conditions of a Mach number of 2.0, a total temperature of 300 K, and a total pressure of 0.55 MPa. The results show that fuel–air mixing is considerably enhanced due to shock-induced flow distortion by adding gas throttling. The strength of downstream backpressure determines the distance of forward movement of the throttling shock wave train and the flowfield structure in the channel. When the mass flux of gas throttling is high, the influence of throttling gas spreads across the expansion section, resulting in significant flow separation in front of the liquid jet. It is found that the spray flashback phenomenon is similar to the flame flashback phenomenon that occurs in the supersonic combustion process under the action of a precombustion shock train. The wall counterrotating vortex pair and induced cavity streamwise vortices are enhanced with the increase of the flux of gas throttling. The relatively high-pressure environment generated by gas throttling promotes the atomization of droplets. As a result, the mixing enhancement mechanism of a liquid jet in a supersonic crossflow with gas throttling is mainly due to the combined effects of 1) the shock waves separating the side wall boundary layer and modifying the local flow state of air in the combustor, which lead to a dramatic increase in fuel–air mixing, and 2) the streamwise vorticity values as well as the residence time resulting from channel blockage elevating.

Model for atomization droplet size and energy distribution ratio at the distal end of an electrostatic nozzle

Electrostatic atomization minimum quantity lubrication (EMQL) employs the synergistic effect of multiple physical fields to atomize minute quantities of lubricant. This innovative methodology is distinguished by its capacity to ameliorate the atomization attributes of the lubricant substantially, which subsequently augments the migratory and infiltration proficiency of the droplets within the complex and demanding milieu of the cutting zone. Compared with the traditional minimum quantity lubrication (MQL), the EMQL process is further complicated by the multiphysical field influences. The presence of multiple physical fields not only increases the complexity of the forces acting on the liquid film but also induces changes in the physical properties of the lubricant itself, thus making the analysis of atomization characteristics and energy distribution particularly challenging. To address this objective reality, the current study has conducted a meticulous measurement of the volume average diameter, size distribution span, and the percentage concentration of inhalable particles of the charged droplets at various intercept positions of the EMQL nozzle. A predictive model for the volume-averaged droplet size at the far end of the EMQL nozzle was established with the observed statistical value F of 825.2125, which indicates a high regression accuracy of the model. Furthermore, based on the changes in the potential energy of surface tension, the loss of kinetic energy of gas, and the electric field work at different nozzle orifice positions in the EMQL system, an energy distribution ratio model for EMQL was developed. The energy distribution ratio coefficients under operating conditions of 0.1 MPa air pressure and 0 to 40 kV voltage on the 20 mm cross-section ranged from 3.094‰ to 3.458‰, while all other operating conditions and cross-sections had energy distribution ratios below 2.06‰. This research is expected to act as a catalyst for the progression of EMQL by stimulating innovation in the sphere of precision manufacturing, providing theoretical foundations, and offering practical guidance for the further development of EMQL technology.

Improving the removal of fine particles in cyclone using heterogeneous vapor condensation enhanced by atomization

Using a heat exchanger to cool high humidity flue gas can create a supersaturated water vapor environment, allowing fine particles to grow into large droplets by heterogeneous vapor condensation, which is conductive to the removal of fine particles by traditional equipment. However, due to the limited condensable vapor obtained by cooling, this technology can only be used in the flue gas with low particle concentration. In this study, atomization droplets were added before the heat exchanger to improve the effect of heterogeneous vapor condensation at high particle concentration, and then coupled with a cyclone separator, which was used for the deep treatment of the flue gas after the wet dedusting system. The particle removal characteristics were investigated through laboratory experiments and bypass experiments in a metallurgical company. The experimental results show that the application of atomization-heterogeneous condensation reduced the particles concentration after cyclone by 74.2 % compared with that of single heterogeneous condensation. Temperature-drop and atomized volume affected the removal of particles with size < 2 μm and > 2 μm, respectively. The industrial flue gas bypass experiment indicated that the system had strong adaptability to fluctuating conditions. When the inlet particle concentration did not exceed 2000 mg/Nm3, the outlet particle concentration can be maintained within 20 mg/Nm3.

Analysis of Atomization Performance of Linear Laval Nozzle under Varied Water Pressures Based on VOF and DPM Models

Particulate matter from coal and stone operations is a primary air pollution source. The traditional nozzle requires high-pressure conditions, and the atomization droplets are large and uneven. This paper aims to study a linear Laval nozzle and investigate the impact of water pressure on atomization performance. The volume of fluid (VOF) model and discrete phase model (DPM) of Fluent are used to simulate the internal and external fields of the nozzle and analyze the velocity, droplet size, and atomization angle. The results show that the optimized water pressure parameters are 0.1 MPa with an air pressure of 0.5 MPa. Droplets in the middle are smaller, while those on the sides are larger. Compared to traditional nozzles, the water pressure is reduced by over 90%, and the Sauter mean diameter (SMD) decreases by over 50%. Moreover, the theoretical spray angle increases by approximately 150%.

Preparation of protective coatings for the leading edge of wind turbine blades and investigation of their water droplet erosion behavior

The damage caused by rain droplet erosion to the leading edge of wind turbine blades is extremely severe. To reduce this issue, in this study, hydroxyl-terminated polybutadiene (HTPB) and isophorone diisocyanate (IPDI) were used as the polyurethane (PU) polyol and curing agent, respectively, to prepare a PU coating with a high resistance to water droplet erosion (WDE) for the protection of the leading edge of wind turbine blades. The effect of n (–NCO):n (–OH) (R-value, n is the molar ratio) on the mechanical properties and WDE resistance of PU coatings, the relationship between the two performances, and the influence of the erosion conditions on the WDE behavior were investigated for the first time. The results show the existence of a correlation between the mechanical properties (hardness, impact, flexibility, and tensile strength) and WDE resistance of the coating. While, a better abrasion resistance is found not to result in a better WDE resistance. The PU coating with an R-value of 1.2 shows an optimal WDE resistance in both atomization and jet erosion experiments. In atomized droplet erosion (ADE) experiments, the change in erosion velocity accelerates the incubation period of coating erosion damage and increases the erosion rate. In jet droplet erosion (JDE) experiments, the damage to the coating is closely related to the erosion angle, reaching a maximum at an impact angle of 60°. Furthermore, in the ADE experiments, various erosion morphologies, such as pits, grooves, cracks, and stepped texture, are observed on the damaged coating surface. While, regarding the JDE experiments, holes, grooves, and cracks are observed. Such damage is caused by the combined effects of water hammer pressure, lateral jets, and local permeation.

Suppression of aerosol dispersion by highly viscoelastic poly(acrylic acid)- and poly(ethylene oxide)-based coolants during bone drilling

Bone drilling in neurosurgical, dental, and orthopedic procedures, combined with the use of coolants, generates a dispersion of bone particles, coolants, and blood aerosols in the air. This poses the threat of airborne transmission of infectious diseases between patients and medical practitioners. Highly viscoelastic polymeric poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO) solutions of various concentrations were used as coolants during bone drilling at different mass flow rates to suppress aerosol generation, thereby mitigating the threat of cross-infection. The results revealed that the PAA and PEO solutions provide less advection than water and a comparable cooling performance. However, excessive viscoelasticity of PEO causes the fluid to rise along the cutting burr (the Weissenberg effect), thereby reducing the cooling coverage area. In contrast, slightly lower viscoelasticity of PEO results in a high cooling coverage area. The cooling coverage area is smaller for the PAA at 20 ml/min because the corresponding PAA solution easily swirls or splashes away from the drilling location. However, at 80 ml/min, the supplied PAA solution sufficiently cools the drilling area, despite the loss through splashing. The numbers of atomized droplets of water and the PAA and PEO solutions were quantified and compared to investigate the degree of aerosol formation and dispersion. The solution with the strongest viscoelasticity most significantly suppressed aerosolization and produced the fewest dispersed aerosol droplets during bone drilling.

Development of Highly Efficient Lamb Wave Transducers toward Dual-Surface Simultaneous Atomization.

Highly efficient surface acoustic wave (SAW) transducers offer significant advantages for microfluidic atomization. Aiming at highly efficient atomization, we innovatively accomplish dual-surface simultaneous atomization by strategically positioning the liquid supply outside the IDT aperture edge. Initially, we optimize Lamb wave transducers and specifically investigate their performance based on the ratio of substrate thickness to acoustic wavelength. When this ratio h/λ is approximately 1.25, the electromechanical coupling coefficient of A0-mode Lamb waves can reach around 5.5% for 128° Y-X LiNbO3. We then study the mechanism of droplet atomization with the liquid supply positioned outside the IDT aperture edge. Experimental results demonstrate that optimized Lamb wave transducers exhibit clear dual-surface simultaneous atomization. These transducers provide equivalent amplitude acoustic wave vibrations on both surfaces, causing the liquid thin film to accumulate at the edges of the dual-surface and form a continuous mist.

Ultrasonic atomization technique for enhancing humidification process in thermal desalination

The need for desalination is expected to evolve, and interests in novel techniques to enhance thermal desalination are developing. Research studies on ultrasonic atomization for desalination application has been observed in the last few years. Hence, this study aims to examine humidification process enhancement using ultrasonic atomization and interaction of atomized droplets with hot air in the humidifier. In the Humidification and Dehumidification (HDH) desalination system examined, the humidifier is equipped with a single ultrasonic atomizer unit which operates continuously with preheated hot air entering the humidifier chamber. The system is investigated for different air flowrates (40 – 100 LPM) and hot air temperatures (40, 50, and 60 °C). The average relative humidity at the humidifier outlet was maximum reaching 94 % for the highest flowrate. The results indicate that increasing hot air temperatures have significant improvement in droplet evaporation which causes higher relative humidity at the outlet, and increasing hot air flowrates have significant impact on the faster response of the humidification process to reach equilibrium.

Experimental and simulation studies on suppressing gas explosions with diverse atomized liquid droplets: Insights for improved safety in mining

Gas explosions represent a prevalent thermodynamic hazard in coal mining, significantly endangering worker safety and the operation's overall safety. Water mist stands out among various explosion suppression techniques due to its high heat absorption capacity and environmental sustainability, offering a promising avenue for application. This study introduces a custom-built pipeline gas explosion testing apparatus to investigate the suppression effects of different atomized liquid droplets on gas explosions. By collecting and analyzing experimental data from pressure sensors under varying conditions within the pipeline, we conduct a thorough comparison of the explosion suppression characteristics attributed to different atomized droplets. Based on this foundation, the Fluent software was used for numerical simulation research to further analyze the explosion suppression effects of different atomized droplets. Additionally, numerical simulations were conducted to optimize the nozzle arrangement. Our findings reveal that an increase in atomization pressure, leading to smaller droplet sizes, significantly mitigates the impulse of the gas explosion shock wave. This indicates a marked inhibitory effect of atomized droplets on gas explosions, with finer droplets showing enhanced suppression capabilities. The simulation results from the optimized nozzle arrangement can provide valuable guidance for on-site deployment. Through a combination of experimental and simulation data, this study conducts a qualitative and quantitative analysis of the suppression mechanisms offered by different atomized droplets, considering parameters such as explosion impulse, blast energy, and explosion indices. The insights gained provide a theoretical foundation for reducing the ring-breaking effect of gas explosions and enhancing explosion suppression strategies, which are crucial for ensuring the safety of coal mining operations.

The formation process and mechanism of coaxial electrostatic atomization of nanofluid oil film droplets

Abstract In coaxial electrostatic atomization cutting, the atomization effect of nanofluid oil film droplets directly affects the cooling and lubrication performance. To further understand the formation process of tiny oil film water droplets in coaxial electrostatic atomization, this paper takes LB2000/water, LB2000/0.1 vol.% graphite water-based nanofluids, LB2000/0.3 vol.% graphite water-based nanofluids, LB2000/0.5 vol.% graphite water-based nanofluids as the research object. Coaxial electrostatic atomization simulation is carried out based on the determined common voltage of the conical jet (-6.5 kV). The formation process of nanofluid oil film water droplets was analyzed using electric field force, charge concentration, and volume force, and the droplet states under different fluid types were compared. The results show that when nanoparticles are added to the inner fluid, the charge concentration increases, the electric field force and volume increase, and the formation speed of the cone jet increases significantly.

Numerical study and experimental validation: A portioned calculation method for a large atomization field

Atomization and sprays are widely used in industry and agriculture. An appropriate atomization simulation method is essential in analyzing the liquid film-breaking process and atomization performance, especially in large-scale atomization field calculations. This study innovatively proposes a portioned method that combines existing fundamental atomization calculation models to balance computational accuracy and speed, finally achieving a full-scale numerical study of large atomization fields. This study employs the volume of fluid (VOF) model to measure the two-phase flow in the inner flow field and applies the discrete particle model (DPM) to analyze droplet behavior in the far-atomization field. In the near-atomization field, the VOF-to-DPM method connects the nozzle with the jet space, providing an effective numerical simulation of the liquid film formation and droplet breakup processes. Additionally, experiments on atomization using a pressure-swirl nozzle at different flow rates were conducted. Experimental data, such as atomization cone angle, flow distribution, and droplet particle size distribution, were obtained, and numerical calculations were performed using the large atomization field partitioned calculation model. The simulation results are utilized to explain the mechanisms of liquid film disintegration, while the experimental results are employed to validate the accuracy of the numerical model. The comparison revealed that the calculated results of the partitioned simulation approach align well with the experimental data. The maximum error in flow characteristics is 9.53%, in atomization cone angle is 6.16%, and in flow distribution is 3.67%, and there is a good agreement in particle size distribution with a maximum error of 17.58% in Sauter mean diameter, validating the accuracy of the portioned calculation method for large atomization fields.

Numerical study of thermocapillary and slip effects on interfacial destabilization under surface acoustic waves

The rapid development of microfluidics has significantly highlighted the role of surface acoustic waves (SAWs) in microfluidic actuation. SAW influences droplet manipulation, inducing interface instability and processes such as droplet splitting, jetting, and atomization, which have been key research focal points. Previous studies have identified a close correlation between these instability mechanisms and three critical parameters: the Marangoni number (Ma), associated with piezoelectric substrate thermal effects; the slip coefficient (β0), related to piezoelectric substrate slip; and the acoustic capillary number (C). Given the intimate link between the aspect ratio (H/L, where H is the characteristic height, and L is the characteristic width of droplets) and atomization size, this study comprehensively investigates the combined effects of these factors on the droplet aspect ratio H/L. Specifically, increases in the acoustic capillary number C and slip coefficient β0 promote reductions in droplet height (H) and outward expansion (L), while the Marangoni number Ma counteracts this expansion, maintaining larger H/L values. This inhibitory effect is particularly pronounced when C and β0 are small but diminishes as their values increase. Additionally, higher values of C and β0 accelerate the convergence of the H/L ratio, whereas Ma decreases the rate of this convergence. Through the coordinated interplay of Ma, β0, and C, multidimensional and fine-tuned adjustments of the droplet aspect ratio H/L over a wide range can be achieved.

Effect of solute concentration on the number of NaCl particles generated by millimeter- and micron-sized droplets

Salt particles generated by aerosol generator are commonly used in air filtration test. As a common phenomenon, the number of generated particles increases with the salt concentration in the atomization solution. Thus far, the dependence of the particle number on the concentration of the atomization solution is not fully understood. In this study, two hypotheses were proposed to explain this phenomenon: i) a single droplet generates multiple solid particles, and the generated particle number is influenced by the salt concentration, and ii) the original droplet number increases with an increase in the salt concentration of the atomization solution. By observing the particle formation process of the levitated millimeter-scale NaCl droplet, one droplet was found to generate one particle in free air. However, whether these results are applicable to micrometer-scale droplets remains to be determined. In situ measurements were performed to detect the size distributions of the original droplets generated by the atomization solutions with various salt concentrations. A more concentrated atomization solution induced a higher number of original droplets. Particle formation patterns of droplets on glass substrates and filaments were demonstrated. Traditional observation methods for droplet drying are unsuitable for studying the particle formation of atomized droplets because of the large difference in droplet size and the existence of external forces.