Spray Cone Research Articles

Shot-to-Shot Deviation of a Common Rail Injection System Operating with Cooking-Oil-Residue Biodiesel

<div>The shot-to-shot variations in common rail injection systems are primarily caused by pressure wave oscillations in the rail, pipes, and injector body. These oscillations are influenced by fuel physical properties, injector needle movement, and pressure and suction control valve activations. The pressure waves are generated by pump actuation and injector needle movement, and their frequency and amplitude are determined by fluid properties and flow path geometry. These variations can result in cycle-to-cycle engine fluctuations. In multi-injection and split-injection strategies, the pressure oscillation from the first shot can impact the hydraulic characteristics of subsequent shots, resulting in variations in injection rate and amount. This is particularly significant when using alternative fuels such as biodiesel, which aim to reduce emissions while maintaining fuel atomization quality. This study examines the shot-to-shot variations in a second-generation common rail system using cooking-oil-residue biodiesel. The results demonstrate that biodiesel properties impact pressure wave oscillation, shot-to-shot variation, and total injection rate. The study also finds that dwell time has a significant effect on the hydraulic characteristics of the second shot, with minimal influence up to a certain value. However, beyond a certain dwell time value (e.g., 0.8 ms in this study), the impact of dwell time on the pressure fluctuation generated by the second shot is limited. Conducting further research could help deepen our understanding of the influence of shot-to-shot deviations. This could involve exploring biodiesel spray characteristics using techniques such as shadowgraph imaging and studying the effect of these deviations on flame propagation and emission formation. Examining engine performance could also provide valuable insights into the effectiveness of the split-injection strategy and biodiesel blends. Additionally, characterizing biodiesel spray using the double-shot technique to examine spray penetration, cone angle, and/or spray impingement and combustion characteristics could be useful in linking it with the shot-to-shot variation investigated in this study. Such research can contribute to advancing the state-of-the-art knowledge on this topic.</div>

Evaluation of the Parameters of the Dispersed Stream Generated by Various Types of Water Nozzles

Aim: The purpose of the research was to determine the parameters of the micro- and macro-structure of the streams generated by nozzles of different types, and to identify potential applications of the tested water nozzles, including firefighting and air pollution removal. Introduction: TF6 FCN, TF6 V, NF 15 and CW 50 water nozzles were tested. At supply pressures of 0.2 MPa, 0.4 MPa and 0.6 MPa, the basic parameters of micro- and macrostructure of the streams were measured and determined: flow rate, spray angle, mass distribution of liquid on the surface (spray intensity), non-uniformity of spray density distribution, and average droplet diameters and spray spectrum. A sputter spectrum analyser, using the photoelectric method, was used to determine the microstructural parameters of the stream. Project and methods: Badaniom poddano dysze wodne TF6 FCN, TF6 V, NF 15 oraz CW 50. Przy ciśnieniu zasilania równym 0,2 MPa, 0,4 MPa oraz 0,6 MPa zmierzono i wyznaczono podstawowe parametry mikro- i makrostruktury strumieni: natężenie przepływu, kąt rozpylenia, rozkład masowy cieczy na powierzchni (intensywność zraszania), nierównomierność rozkładu gęstości zraszania oraz średnie średnice kropel i widmo rozpylenia. Do określenia paramentów mikrostrukturalnych strumienia zastosowano analizator widma rozpylenia, wykorzystujący metodę fotoelektryczną. Results: The tested nozzles generated dispersed streams with different parameters. Among the analysed nozzles, the highest degree of dispersion was obtained for the TF 6 FCN sample, whose average Sauter mean diameter (SMD) reached a value of 217.3 μm. In comparison, for the NF15 nozzle this parameter was 945 μm. The spray spectra indicate a high homogeneity of water dispersion in the stream produced by the nozzles TF 6 FCN and CW 50. From the distribution of mass sprinkling density, the CW 50 nozzle shows the greatest uniformity of spraying. At the same time, however, it reports a small amount of water, since the value of the spray density for this product did not exceed 100 g/( m2 · s), while for the NF 15 nozzle it was more than 2,700 g/( m2 · s). The obtained spray angles were close to those declared by the nozzle manufacturer. In the tests of all samples, a slight effect of supply pressure on the values of this parameter was observed. Conclusions: Among other things, the tests made it possible to conclude that in the range of supply pressures of 0.2÷0.6 MPa, the values of disperse angle and spray area of the analysed nozzles were constant or the recorded differences were insignificant. In addition, it was determined that in the case of nozzles with full spray cones, an increase in supply pressure (within the range of declared operating values) has little effect on changing the parameters of the micro- and macro-structure of the stream. The conducted tests showed the potential use of two nozzles (TF6 FCN, CW 50) in low-pressure fog extinguishing systems producing fog with SMD droplet diameters > 200 μm. For the absorption of hazardous substances, it is recommended to use nozzles with a large spray angle and a full spray cone, which, as tests have shown, produce uniform streams with small droplet diameters. Keywords: water nozzles, water spray, spray spectrum, mass spray density, water mist

CFD-DPM data-driven GWO-SVR for fast prediction of nitrate decomposition in blast furnaces with nozzle arrangement optimization

In the industrial production process, it is important to improve the productivity of blast furnaces in response to the worldwide call for energy saving and emission reduction. In this study, a data-driven method using computational fluid dynamics (CFD) is developed for the rapid prediction of nitrate decomposition in a blast furnace. The method includes the creation of a CFD database, for which nozzle arrangement patterns, relative distances, spray cone angles and temperatures are simulated and collected. Support vector regression (SVR) hyperparameters are optimized using genetic algorithm (GA), particle swarm optimization (PSO), and gray wolf optimizer (GWO). Machine learning interpretability methods shapley additive explanations (SHAP) and partial dependence plots (PDP) are used to analyze the impact of features on prediction results. The results show that the hybrid GWO-SVR model has a better performance, with the degree of fit (R2) improving from 0.7752 to 0.9719. When the distance is taken around 0.58, increasing the temperature and cone angle is more favorable to improve the decomposition rate of the blast furnace. SHAP method shows that only the arrangement 2 and 4 have a positive effect on improving the decomposition rate. The response time for accurate prediction of nitrate decomposition rate is 259200 times shorter than that of industrial-scale CFD simulations. The method is also used to determine the best combination of solutions. This cross-disciplinary approach provides a time-saving and cost-effective tool for improving the response of blast furnace productivity to changes in nozzle arrangement.

Processes Occurring in a Coolant Spray Cone

Processes Occurring in a Coolant Spray Cone

Factors affecting the highly dispersed spray when applying fertilizers

The article is devoted to devices for subsurface fertilization in the form of drip-air mixtures. A comparative analysis of spray mixers with centrifugal and jet nozzles has been carried out. The article presents the results of a study on the spray dependence on the ratio of air and liquid pressure with increasing fluid flow and steady air flow. It has been established that a spray mixer with a centrifugal nozzle gives a thinner spray cone is better in its operational qualities and will more fully meet the requirements for devices for intra-soil application of liquid fertilizers. In addition, it was determined that according to agrotechnical requirements, the average diameter of liquid droplets injected into the soil must be kept constant, and the flow rate must be changed, leaving the device speed and the compressor operating mode unchanged.

The cavitation flow and spray characteristics of gasoline-diesel blends in the nozzle of a high-pressure common-rail injector

In compression-ignition engines, gasoline-diesel blends have been widely concerned for its potential to reach 50% thermal efficiency and ultra-low emissions. Due to physical property difference between the two fuels, the spray atomization characteristics of the blended fuels are different from that of a single fuel, and the cavitation flow characteristics of the blends in the high-pressure nozzle and their impact on the spray are not well understood. In this paper, the visualization of cavitation flow and spray characteristics of five different proportion blended fuels (D100G0, D80G20, D60G40, D40G60, D20G80) was carried out. The influence of fuel properties corresponding to the gasoline-diesel mixing ratio on the initial generation of vortex-induced cavitation, the development of transient cavitation flow process and the injection rate and spray characteristics were studied respectively. For the tapered orifice nozzle, string cavitation is captured mainly concentrating in the needle opening initial period and closing end period, which is the main factor of spray instability and fluctuations. At the injection starting, the addition of gasoline into the diesel fuel resulted in a significant increase in string cavitation strength and larger injection rate compared to the pure diesel, even if the percentage of gasoline added is small. However, the different gasoline addition ratios have little effect on the maximum intensity of string cavitation and the duration of string cavitation in the nozzle. Accordingly, the addition of gasoline increased the overall spray cone angle and spray fluctuations throughout the injection process. Meanwhile, as the injection volume increased, the injection rate curve in the initial process is flat at first and then become steep which was precisely related to the cavitation of the vortex line in the nozzle. The findings of this paper are important guidelines for the determination of fuel injection strategies and spray analysis of gasoline-diesel blends for compression-ignition engines.

Effects of Key Structure of Pressure Swirl Nozzle on Atomization Performance

The structure of the pressure swirl nozzle is the key factor affecting the atomization quality. Optimal design of nozzle structure is conducive to improving the atomization quality and has important significance for improving the efficiency and stability of the combustor. The effect of the swirl section diameter, the contraction section angle, the straight section diameter, and the expansion section angle on the spray cone angle and the liquid film thickness is studied by numerical simulation. The results show that the liquid film thickness and spray cone angle both decrease with the increase of the expansion section angle. As the straight section diameter increases, the spray cone angle and liquid film thickness both increased. Both the spray cone angle and the liquid film thickness have an optimal contraction angle value that is 60° and 45°, respectively. The increase in the ratio of the swirl section diameter to the straight section diameter can increase the liquid axial velocity. When the nozzle outlet has an expansion angle, the thickness of the liquid film is reduced. When the expansion section angle, the straight section diameter, the contraction section angle, and the swirl section diameter of the nozzle is 30°, 4 mm, 45°, and 12 mm, respectively, the atomization performance of this nozzle is the best.

The effects of sub/supercritical conditions on the spray interface characteristics of alkane fuel

ABSTRACT Alkane fuels are widely used in engines. The spray characteristics in supercritical environments are very different than in subcritical environments, and supercritical environments significantly impact the formation of the gas mixture in the engine. In this paper, the spray images of n-heptane and n-tetradecane in subcritical (500K-2MPa) and supercritical (700K-4MPa, 800K-6MPa) environments were obtained on the constant volume spray test platform. The effects of the supercritical environment and carbon chain length of alkane fuel on spray characteristic parameters were investigated. The results showed that the carbon chain length and ambient pressure are the main factors of penetration. The ambient pressure is the main factor of the spray cone angle and the spray non-liquid layer thickness. Compared with n-heptane, in the 500K-2MPa (subcritical) environment, the cone angle of n-tetradecane was reduced by 2°, the penetration was increased by 10 mm, and the spray non-liquid layer thickness was reduced by about 1 mm. In the 800K-6MPa (supercritical) environment, the cone angle of n-tetradecane was increased by 2°, the penetration was increased by 10 mm, and the spray non-liquid layer thickness was increased by about 1.2 mm. In addition, the calculation model of alkane fuel spray penetration in sub/supercritical environments was modified and achieved 95% prediction accuracy.

Studies of Jet A1 Fuel Atomization Through Non Circular Orifices


 
 
 The performance of the liquid rocket engine depends on the atomization behavior of the fluid being injected into the combustion chamber. Generally, a plain injector with a circular orifice has been used in the injector, but it has the disadvantage of having a low spray cone angle. The breakup length, mean droplet diameter, and Sauter mean diameter is also higher. Thus, to overcome these drawbacks, non-circular orifices have been utilized in the present study. The shapes used for non-circular orifices are semi-circular and plus. The results obtained with the non-circular orifice is compared with the circular orifices of the same area ratio. The working fluid used for the studies is Jet A1 fuel. Studies were also conducted with different L/D ratios by choosing an effective orifice length to reduce the upstream losses. The axis-switching phenomena were observed with the semi-circular as well as with the plus jets. The mean droplet size of the circular jets was more prominent compared to non-circular jets, and the Sauter mean diameter of non-circular jets droplets was smaller than that of the circular jet droplet. The spray cone angle has increased by 290% for plus jets and 30% for semi-circular jets compared to circular jets.
 
 

An Experimental Study on the Injection Characteristics and the Macroscopic Spray Characteristics of Rapeseed Oil-Diesel Fuel Blends

In this study, the injection processes and spray behavior of diesel fuel (DF), rapeseed oil (RO) and their fuel blends (RO25, RO50, RO75) have been qualitatively and quantitatively analyzed to identify the differences in the injection rate and the spray parameters. The volumetric and mass injection rates, the spray penetration, the spray cone angle and the spray area under non-evaporation conditions in a nitrogen-filled camber were analyzed. The results showed that rapeseed oil leads to a decrease in the peak injection rate due to its higher density and viscosity. Moreover, rapeseed oil and its blends with mineral diesel oil exhibited smoother rising slopes at the start of injection. The spray tip penetration was the longest for the rapeseed oil and the spray tip penetrations of the fuel blends RO25, RO50 and RO75 were arranged between the values of DF and RO. As the injection pressure increased, the differences in the spray tip penetrations diminished. Increasing the amount of rapeseed oil in fuel blends resulted in a smaller spray cone angle compared to diesel fuel. The spray area of all tested fuels increased significantly with increasing spray tip penetration, the spray area of RO was consistently lower than that of diesel fuel.

A deep-learning framework for spray pattern segmentation and estimation in agricultural spraying systems

This work focuses on leveraging deep learning for agricultural applications, especially for spray pattern segmentation and spray cone angle estimation. These two characteristics are important to understanding the sprayer system such as nozzles used in agriculture. The core of this work includes three deep-learning convolution-based models. These models are trained and their performances are compared. After the best model is selected based on its performance, it is used for spray region segmentation and spray cone angle estimation. The output from the selected model provides a binary image representing the spray region. This binary image is further processed using image processing to estimate the spray cone angle. The validation process is designed to compare results obtained from this work with manual measurements.

Spray and Combustion Characteristics of CTL-Diesel Fuel Blends in a Constant-Volume Combustion Chamber.

Coal-to-liquid (CTL) fuel is considered a promising alternative fuel for diesel engine applications in China owing to its excellent fuel properties. However, little research on the spray and combustion processes of CTL fuel has been scarce. Therefore, in this study, the spray and combustion characteristics of diesel fuel blends with different CTL fuel blending ratios were investigated in a constant-volume combustion chamber. The results show that under non-evaporation conditions (300 K), a longer spray tip penetration (STP) and enlarged spray cone angle (SCA) were obtained with a higher injection pressure owing to the enhanced turbulent interaction. The SCA of CTL fuel blending was larger than that of diesel fuel owing to its lower viscosity and slightly shorter STP. Under the evaporation condition (700 K), with an increase in the CTL mixing ratio, both the STP and SCA of the fuel exhibited a decreasing trend owing to the higher volatility. Meanwhile, as the CTL mixing ratio increased, the ignition delay period was shortened, and the flame lift-off length decreased, whereas both the integrated natural flame luminosity and combustion duration increased. The cetane number of CTL fuel plays an important role in the occurrence of these results.

Effect of the arrangement of two nozzles on morphology, velocity, and particle size distribution of artificial snow-making spray field

A decline in natural snow due to global warming increases the reliance of ski resorts on artificial snow. To improve the formation rate and snow amount of artificial snow under any environmental conditions, it is necessary to use atomization technology that maintains the size of liquid drops of the snow-making spray field below a critical size, thus maximizing the number of freezing droplets into ice crystals. Here, we study the effects of the gas–liquid mass-mixing ratio (GLR) and the spacing (d) between two nozzles on the characteristics of the snow-making spray field produced by atomization technology for GLR of 0.05, 0.10, 0.15, and 0.2 and d of 5, 10, 15, and 20 cm. The measurement of the morphology, velocity, and particle-size distribution of the snow-making spray field is conducted by a laser particle-size measuring instrument, particle image velocimetry, and a high-speed camera. Our results show that both the spray cone and the intersection angles increase with the increase in the GLR in a two-nozzle arrangement, while the degree of interference between the nozzles increases with the decrease in spacing, d. We also find that the inward offset of the spray is the main reason for the increase in the intersection angle and the interference area and the deviation of the spray midline. In addition, we compare the characteristics of the spray field produced by the single and the two-nozzle systems. We conclude that the flow-field velocity of the single nozzle is smaller than that of the two nozzles and the velocity gradient of the liquid drops in the two-nozzle flow field varies greatly. The maximum vorticity (Max = 147) in the case of the two-nozzle arrangement is much larger than that of the single nozzle. Moreover, by analyzing the two-nozzle flow field at different spacings, we find that the particle-size distribution is most uniform for GLR = 0.10 and d = 15 cm. Thus, our study elucidates the characteristics of spray fields suitable for snow-making toward achieving higher quality and more efficient snow-making processes.

锥形风场式防飘喷雾流场特性及沉积性能试验研究

Conical wind field anti-drift spray is an innovative form of anti-drift operation using auxiliary air flow, which can resist the generation of vortex, and has the characteristics of reducing the droplets loss with wind at the vertical height. In order to explore the characteristics of spray flow field and droplet deposition performance under conical wind field, the structure and working principle were analyzed based on the basic principle of proton dynamics. Spraytec and PDPA system were used to explore the distribution characteristics of spray flow field. Box-Behnken experimental design was used to analyze the droplet deposition performance. The optimum combination of the working parameters with spray height is 0.46 m, the spray pressure was 0.34 MPa, the conical wind speed was 16.16 m/s, and the droplet deposition amount was 3.39µL·cm-2. The droplet deposition amount was optimal.

Review of physicochemical properties and spray characteristics of biodiesel.

The United Nations Sustainable Development Goals by 2030 deal with seventeen goals for the planet's sustainability. The present review focuses on affordable and clean energy through the effective combustion of fuels with minimal pollution. Effective fuel spray characteristics are essential for combustion among various parameters and fuel properties. The inherent nature of the fuel has a functional relationship with the injection and injectors' conditions. Therefore, the study of fuels' physicochemical properties is essential. This review deals with the spray characteristics of biodiesel. Biodiesels in its purest form and blended with diesel, di-n-butyl ether, dimethyl ether, diethyl ether, ethanol, and butanol are considered for the study. The physicochemical properties of biodiesels, injection conditions, and injector constraints are analyzed to understand the spray process. The atomization features such as spray tip penetration, Sauter mean diameter, spray cone angle, spray area, and spray volume are analyzed. The chemical properties of biodiesel are utilized to describe the spray's transient behavior. In addition, supporting systems for spray diagnostics and models are also discussed. The highlighted significant spray challenges features and future research direction benefit the fuel and combustion community.

Fractal Analysis of Fuel Nozzle Surface Morphology Based on the 3D-Sandbox Method.

The dual oil circuit centrifugal fuel nozzle is made of martensitic stainless steel, which has complex morphological characteristics. The surface roughness characteristics of the fuel nozzle directly affect the degree of fuel atomization and the spray cone angle. The surface characterization of the fuel nozzle is investigated by the fractal analysis method. A sequence of images of an unheated treatment fuel nozzle and a heated treatment fuel nozzle are captured by the super-depth digital camera. The 3-D point cloud of the fuel nozzle is acquired by the shape from focus technique, and its three-dimensional (3-D) fractal dimensions are calculated and analyzed by the 3-D sandbox counting method. The proposed method can characterize the surface morphology well, including the standard metal processing surface and the fuel nozzle surface, and the experiments show that the 3-D surface fractal dimension is positively correlated with the surface roughness parameter. The 3-D surface fractal dimensions of the unheated treatment fuel nozzle were 2.6281, 2.8697, and 2.7620, compared with the heated treatment fuel nozzles dimensions of 2.3021, 2.5322, and 2.3327. Thus, the 3-D surface fractal dimension value of the unheated treatment is larger than that of the heated treatment and is sensitive to surface defects. This study indicates that the 3-D sandbox counting fractal dimension method is an effective method to evaluate the fuel nozzle surface and other metal processing surfaces.

Numerical simulation investigation of drug deposition process during nasal administration with auxiliary airflow

Successful delivery of drugs to the Olfactory region (OR) is the key to treating diseases through the nasal cavity. The purpose of this paper is to investigate the effect of auxiliary airflow on particle deposition in the OR during nasal drug administration. A realistic 3D nasal ensemble model was reconstructed from CT scans of the head of a healthy adult. Computational fluid dynamics (CFD) was used to simulate the effect of auxiliary airflow on the deposition of drug particles in the OR during nasal administration. The discrete phase model (DPM) was adopted to track the deposition trajectories of drug particles. Three auxiliary airflows were selected together with three spray cone angles, four particle sizes, five drug particle delivery velocities and three specific injection positions on the deposition fraction of drug particles in the OR were analyzed. The results indicated that the effect of auxiliary airflow on the deposition fraction of drug particles of different particle sizes in the OR is significant. The delivery efficiency of injection position C is always the greatest. A delivery velocity of 15 m/s is more favorable for nasal administration and the effect of spray cone angle is proportional to the auxiliary airflow. Computational results should be helpful for experimental studies and future nasal optimization.

Deposition of spray droplets by four spray nozzles and two working pressures

The deposition of spray droplets on the target can be influenced by the type spray nozzle used, as well as the employed working pressure. Thus, with the commercial availability of new spray nozzles, performance studies with the new models become necessary. This study was carried out to evaluate ground deposition of spray droplets by four models of spray nozzles, at two working pressures. The experiment was conducted in Dourados/MS, in September 2020, with strip design and 4x2 factorial scheme, with five repetitions. Four spray nozzles were used (single flat fan, ST-IA 02 model; angle flat fan MUG 02; hollow cone MGA 02; and double flat fan ST-IA/D 02), working at 30 and 50 psi pressures. The distance between each nozzle was 50 cm, 60 cm above the ground. Water-sensitive paper was used and, immediately after application, the paper was scanned using the DropScan® tool. Subsequently, the number of droplets, coverage, amplitude, dispersion, Volume Median Diameter (VMD), Number Median Diameter (NMD), DV09, and DV01 were evaluated. The hollow cone spray nozzle provided a higher number of droplets and greater coverage compared to the other nozzles for the studied weather conditions.

An investigation of the effect of chamber temperature on macroscopic spray characteristic under GCI engine conditions

Spray characteristics play an important role in the application of gasoline compression ignition (GCI) engines because it affects engine performance as well as engine design. In this study, the influence of temperature on the non-vaporizing spray process was evaluated through the experimental process on the constant volume chamber (CVC) with simulated conditions of the GCI engine. The experimental matrix was constructed by varying key factors, including chamber temperature, fuel injection pressure, and chamber gas density. The CVC with built-in heaters allows for temperature variations at 323 K, 398 K, and 423 K. To accommodate low load conditions, the fuel injection pressure is varied between 50 MPa and 110 MPa. Simultaneously, chosen variations of gas density, including two levels of chamber density are selected at 15 kg/m3 and 30 kg/m3 respectively. In addition, the injector angles are arranged at 90° (vertical) and 180° (horizontal) to create an overview of the spray characteristics for the case study of GCI engine conditions, viable for future studies using a constant-volume combustion chamber (CVCC), or even rapid compression engine machine (RCEM) in which the injector is commonly set horizontally. The gasoline blended with biodiesel by volume percentage consisting of 80% gasoline and 20% biodiesel was used as the main fuel in this study, namely the GB20 blend. The results of the spray characteristics collected through the images of the spray process based on the Schlieren optical method and the highspeed camera, consisting of the spray evolution and penetration length, spray penetration rate, spray area, as well as the spray cone angle are investigated. The difference in the spray process is denoted as the chamber temperature is increased. The spray penetrates to the chamber wall limit more quickly at elevated temperatures. The results were recorded as a decrease in impingement time by 12% and 9.5%, respectively, at the injection pressure of 50 MPa together with an ambient gas density value of 15 kg/m3. The cone angle of the spray tends to reduce by approximately around 3° to 10° in all experimental cases when the chamber temperature is high. However, when entering the post-phase at 450–600 μs, cone angle differences are negligible during the injection reaching the stable phase.

Numerical and experimental study of the effects of tangential to axial velocity ratio and structural parameters inside the nozzle on spray characteristics

Pressure swirl nozzles are widely applied in spray cooling, dust removal, and fuel injection. To better connect the nozzle structure with the internal flow to analyze their influence on spray parameters, this paper designs a nozzle structure and uses experimental measurement and computational fluid dynamics simulation methods to investigate the influence of the nozzle's tangential velocity to axial velocity ratio (vτin/vzin) and the swirl diversion channel eccentric distance (dl) on the spray parameters. A phase Doppler particle analyzer was used in the experiment study to determine the spray axial velocity (vz) and sault mean diameter (D32). In the simulation investigation, the Eulerian multiphase flow model was used to calculate the multiphase flow field of the spray. The results showed that dl and vτin/vzin both have an obviously linear relationship to the peak location (rpeak) of each spray parameter. It means that dl plays similar roles as the vτin/vzin, which can enhance the swirl strength inside the nozzle and increase the spray cone angle. The rpeak of liquid phase volume fraction (αw) and D32 of the droplet particle are always greater than the rpeak of vz. The analysis of the flow field inside the spray orifice indicates that as the vτin/vzin rises, the liquid in the nozzle orifice tends to move farther from the central axis, causing atomization to occur more upstream. This study serves as a reference for the flow analysis and structure design of the pressure swirl nozzle.