Nozzle Spray Angle Research Articles

Numerical simulation of flow and mass transport in KDP crystal growth using solution alternate jetting method

In response to the limitations of some previous crystal growth method, which cannot generate ‘back-and-forth shear flow’ in rotating-crystal method and the partial realization of ‘back-and-forth shear flow’ in the crystal two-dimensional and three-dimensional motion methods, a novel KDP crystal growth method, named solution alternate jetting method, was proposed. This method can achieve complete coverage of crystal faces with ‘back-and-forth shear flow’. Numerical simulation results indicate that solution alternate jetting method outperforms rotating-crystal growth method and crystal two-dimensional and three-dimensional motion methods in terms of time-averaged supersaturation and its standard deviation on crystal faces. The jet velocity has a significant impact on the magnitude and distribution of time-averaged supersaturation on crystal faces. Other operating conditions, including the vertical distances from the nozzle outlet to the crystal surface, alternate jetting cycle, nozzle spray angle, and special motion velocity, have a relatively minor impact. Crystals grown with less than 50% ‘back-and-forth shear flow’ in the crystal two-dimensional and three-dimensional motion methods had significantly improved quality compared to rotating-crystal growth method. Therefore, the solution alternate jetting method, capable of achieving the ideal ‘back-and-forth shear flow’, undoubtedly holds promising application prospects.

Computational Fluid Dynamics Study on Bottom-Hole Multiphase Flow Fields Formed by Polycrystalline Diamond Compact Drill Bits in Foam Drilling

High-temperature geothermal wells frequently employ foam drilling fluids and Polycrystalline Diamond Compact (PDC) drill bits. Understanding the bottom-hole flow field of PDC drill bits in foam drilling is essential for accurately analyzing their hydraulic structure design. Based on computational fluid dynamics (CFD) and multiphase flow theory, this paper establishes a numerical simulation technique for gas-liquid-solid multiphase flow in foam drilling with PDC drill bits, combined with a qualitative and quantitative hydraulic structure evaluation method. This method is applied to simulate the bottom-hole flow field of a six-blade PDC drill bit. The results show that the flow velocity of the air phase in foam drilling fluid is generally higher than that of the water phase. Some blades’ cutting teeth exhibit poor cleaning and cooling effects, with individual cutting teeth showing signs of erosion damage and cuttings cross-flow between channels. To address these issues, optimizing the nozzle spray angle and channel design is necessary to improve hydraulic energy distribution, enhance drilling efficiency, and extend drill bit life. This study provides new ideas and methods for developing geothermal drilling technology in the numerical simulation of a gas-liquid-solid three-phase flow field. Additionally, the combined qualitative and quantitative evaluation method offers new insights and approaches for research and practice in drilling engineering.

Numerical Simulation on the Spray Angle of the Dual-layer Hole Nozzle in a Partition Combustion System of the Diesel Engine

To study the effect of the spray angles of the dual-layer hole nozzle on the combustion and emissions performance in the partition combustion system, the in-cylinder spray, mixture formation and combustion processes of the new combustion system were simulated and investigated using AVL FIRE software. The results show that, compared with the variation of the lower-layer spray angles, the change of the upper-layer spray angles has a great influence on the instantaneous heat release rate. The increasing spray angles of the lower-layer holes lead to reduced peak values of the heat release rate in the cylinder. In all the spray angle cases, the first fire area of the cylinder is in the B zone of the combustion chamber. Compared with lower-layer spray angle, the upper-layer spray angle has a greater impact on the airflow disturbance in the combustion chamber. Appropriately increasing the upper-layer spray angle facilitates the mixing of fuel and air in the combustion chamber and reduces the unburnt fuel equivalence ratio. When the spray angles of the upper- and lower-layer holes are 157° and 112°, respectively, the combustion indicates power has the largest value of 12.18 kW. At the same time, the Soot emission is also the smallest, with a value of 0.52 g/kW·h.

Study on the influence of airflow disturbance on spray atomization

The droplet distribution characteristics are one of the key factors that determine the dust suppression effect of spray system. In order to study the droplet distribution characteristics under different working conditions, the influence mechanism of wind speed and spray angle on droplet distribution characteristics was studied based on Fluent software. The results show that the increase of wind speed and spray angle will increase the lateral momentum of droplets, resulting in the increase of longitudinal height and lateral length of spray belt. The change of spray angle causes the change of the distribution ratio of transverse momentum and longitudinal momentum of droplets. With the increase of spray angle, the transverse momentum of droplets increases and the longitudinal momentum decreases, resulting in the increase of the longitudinal height and length of spray belt. In engineering practice, attention should be paid to the coordinated control of nozzle height, spray angle and airflow speed.

Study on duplex air-blast atomizers spray in the engine real operation conditions

Air-blast atomizers are widely used in passenger aircraft engines. In these atomizers, high-speed airflow is used for improved fuel atomization, and as a result, better combustion. The key purpose of this research is to investigate the duplex air-blast atomizers according to the engine data in the real operational conditions with the help of experimental method and numerical solution. When analyzing the variations in fuel sprays under different application conditions, it is important to consider not just one but multiple parameters such as fuel mass rate, air mass rate, and combustion chamber pressure. However, analyzing the individual effects of these parameters can be challenging as they change simultaneously. To address this, a dimensionless number namely K was defined, which takes into account the combined effect of fuel mass rate, air mass rate, and combustion chamber pressure. The results showed that when K decreased by 31.25%, the spray angle of nozzle 1 and nozzle 2 increased by 10.09% and 48.15%, respectively, while the average droplet diameter caused by primary breakup for nozzle 1 and nozzle 2 decreased by 76.29% and 71.57%, respectively. The secondary breakup was somewhat similar, and for nozzle 1 and nozzle 2, the average droplet diameter decreased by 76.5% and 71.88%, respectively. It is worth noting that the average error for spray cone angle in the simulation compared to the experimental results was 6.47%. The results of this research, in addition to causing a better understanding of the atomization processes in air-blast atomizers, can be useful for aerospace engineers.

Numerical simulation on gas-droplet flow characteristics and spray evaporation process in CFB-FGD tower

Nozzle arrangement in the nozzle spray system has a significant impact on the gas-droplet flow characteristics and the temperature distribution within the circulating fluidized bed flue gas desulphurization (CFB-FGD) tower, which is critical to the SO2 removal efficiency. The effects of spray direction, nozzle number and nozzle spray angle on gas-droplet distribution and temperature distribution inside the FGD tower are investigated with numerical simulation based on a Eulerian-Lagrangian mathematical model. An optimal nozzle arrangement scheme is proposed to improve the contact between gas and water droplets and the flue gas temperature distribution. Results show that upward spray direction is beneficial to the interaction between water droplets, improving gas-droplet flow characteristics and spray evaporation process, and water droplets number trapped by tower wall could be reduced in the water droplets evaporation. With the increase in nozzle number, it is conducive to the contact between flue gas and water droplets to increase the evaporation efficiency of water droplets, as well as the uniformity of temperature distribution inside the tower. With nozzle spray angle increases from 30° to 120°, flue gas velocity decreases, water droplets number trapped by the tower wall increases. The temperature distribution at different cross-section is the most uniform when the nozzle spray angle is 60°.

Metal Coating by TIG Arc Deposition Method

Metal (Aluminum) coating was prepared on stainless steel substrate by arc deposition method using TIG Welding machine. Plasma spray is a type of metal coating that is widely used in the industry and its preparation cost is expensive. It is also the most flexible method to apply a wide variety of coatings on a substrate. To reduce the cost of the set-up, the plasma will be generated by using a TIG welding machine to replace the plasma spray. The use of powder which is aluminium as a coating raw material causes almost no restrictions on the use of coating materials used in the plasma melting process. The changing parameters in this experiment are the angle nozzle powder and the flow rate of the working gas which is Argon (Ar) gas and the substrate used is SUS304 stainless steel and the feedstock powder used is Aluminium (Al) powder with an average size of 5 μm. Flow rate used in this study was 10,20 and 30 l/min of Ar and the powder nozzle spray angle was 45°, The live image, diameter, thickness, and surface roughness of the coatings were systematically analyzed using LEXT OLS5000 3D Measuring Laser Microscope.

ANALISIS PERFORMA TURBIN PELTON SUDU SEGITIGA DENGAN VARIASI SUDUT SEMPROT NOSEL

The availability of electrical energy in Indonesia is a very important factor in encouraging development. Increased development, especially in the industrial sector in the form of factories and home industries, continues to grow rapidly. These developments include economic and population growth, so that the need for electrical energy continues to increase. The Pelton turbine is an electrical energy generator that utilizes water as a propeller or bucket on the rotating wheel of the Pelton turbine. So that, it is expected as an alternative to provide electrical energy needs, especially in the industrial sector. This study aims to determine the effect of variations in the angle of the nozzle spray on the triangular blade on the performance of the Pelton turbine. The variations of the nozzle spray angle include 30º, 45º, and 90º. Each nozzle spray angle is varied to the valve opening angle of 60º, 75º, 90º with lamp loads of 0, 5, 10, 15, 20, 25 Watt. Based on the results of this study, it is proven that the nozzle spray angle of 90º has the best results at a valve opening angle of 90º and a lamp load of 15 Watt which produces a generator power of 6.784 Watt with an efficiency of 54.04%. Keywords— Pelton turbine with triangular blade, nozzle spray angle, valve opening angle, generator power, efficiency.

Analysis and Optimization of an Aftermarket Intercooler Spray‟s Nozzle

Abstract— Nowadays an intercooler is commonly integrated in vehicles to cool the air during induction. However, the intercooler does not perform effectively in countries where the climate is humid and hot as the air temperature is relatively higher. Therefore, this study is focused at developing an aftermarket intercooler spray to combat this predicament. The goal of the study was to improve the performance of a cooling-spray-integrated topmount intercooler via the analysis of nozzle diameter and spraying angles. Experiments were conducted on five nozzle types and three spraying angles: 00 , 150 and 300 . It was observed that the efficiency of the intercooler with the spray cooling unit was improved from 89.7% to 95.33%. A B1/8BX3 Hollow Cone Nozzle gave the highest efficiency, followed by B1/8QPPA+QPHA-5 Standard Full Cone Nozzle, HB1/8VV8007 Flat Fan Nozzle, HB1/8VV-6507 Flat Fan Nozzle and B1/8GG-4.3W Standard Full Cone Nozzle. The highest efficiency was observed at nozzle spray angle of 150 . Nozzle diameter and spraying angle were found critical in ensuring an enhanced overall performance of the intercooler. Keywords —Intercooler; Nozzle; Spray angle; Optimization

Construction of a theoretical model for fan nozzles with precise atomization angles for plant protection

The fan nozzle is widely used in the process of pest control in agriculture and forestry. The spray angle of the nozzle is an important characterization parameter in the atomization of liquids. The spray angle of the nozzle is an important characterizing parameter in the liquid atomization process. It affects the flow field at the exit of the nozzle, thereby affecting the size and velocity of the droplets, and further affecting the deposition effect of the droplets on the crop. Therefore, its research is of great significance for improving the deposition of liquid on plants and controlling pests and related diseases. Based on the classical theory of predecessors and considering the parameters of the flat fan nozzle, we further optimized the theory at the structural level by means of a simulation test and built a spray angle theoretical model taking into account the parameters of the inner chamber of the nozzle. We arrived at the following conclusions: (1) the average error of the spray angle measured by the simulation test and the actual test spray angle was 2.95%, the maximum spray angle deviation value was 2.81°, and the result proves that the simulation test parameter setting is accurate; and (2) the average error between the actual measured value and the theoretical model calculation value was 3.56%, the maximum spray angle deviation was 4°, through the actual test comparison, and the spray angle error of the theoretical model was within the allowable error range of industry production. It was proved that the model could effectively reflect the changing law of spray angle of the flat fan nozzle.

Average Degree of Coverage and Coverage Unevenness Coefficient as Parameters for Spraying Quality Assessment

The purpose of the research was to determine the influence of selected factors on the average degree of coverage and uniformity of liquid spray coverage using selected single and dual flat fan nozzles. The impact of nozzle type, spray pressure, driving speed, and spray angle on the average degree of coverage and coverage unevenness coefficient were studied. The research was conducted with special spray track machinery designed and constructed to control and change the boom height, spray angle, driving speed, and spray pressure. Based on the research results, it was found that the highest average coverage was obtained for single standard flat fan nozzles and dual anti-drift flat fan nozzles. At the same time, the highest values of unevenness were observed for these nozzles. Inverse relationships were obtained for air-induction nozzles. Maximization of coverage with simultaneous minimization of unevenness can be achieved by using a medium droplet size for single flat fan nozzles (volume median diameter (VMD) = 300 μm) and coarse droplet size for dual flat fan nozzles (VMD = 352 μm), with low driving speed (respectively 1.1 m∙s−1 and 1.6 m∙s−1) and angling of the nozzle by 20° in the opposite direction to the direction of travel.

Research on the sterilization effect of hydrogen peroxide and equipment optimizatio

Hydrogen peroxide sterilization is widely used in food packaging, public health and other fields. The sterilization effect is related to the vaporization spray time and nozzle parameters. This paper uses AnsysFluent software to mathematically simulate the flow field and concentration distribution of vaporized hydrogen peroxide in the sterilization space; and verify the correctness of the numerical simulation results through field experiments. UDF module is used to describe the component concentration of the nozzle, and the distribution of vaporized hydrogen peroxide is analyzed by changing the nozzle spray angle and spray speed of the equipment, and the spray time T required to reach the standard concentration in the sterilization space is the shortest and the hydrogen peroxide dosage Q is the minimum For the goal, optimize the design parameters. The results show that when the spray speed is 4.8m/s and the spray angle is -18°, the spray time required to reach the sterilization standard is the shortest, and the amount of hydrogen peroxide is the least. This article provides a theoretical basis for the improvement of vaporized hydrogen peroxide sterilization equipment.

Numerical optimization of a diesel combustion system to reduce soot mass and particle number density

In view of the recent emission legislations imposing a limit on the soot particle number density, a numerical optimization has been presented for a constant speed heavy-duty diesel engine to reduce soot particle number density while ensuring no penalty on NOx emissions. Closed cycle combustion simulations have been performed at three loads with the sectional soot model coupled to gas phase kinetics. The combustion model has been tuned at each load to ensure a good agreement for in-cylinder pressure, heat release rate and exhaust emissions. The validated combustion model has been used to study the effect of various parameters like intake swirl, start of injection, number of nozzle holes, spray angle and piston bowl shapes. Combustion simulations have been performed for every case of a full factorial design of experiments with 486 cases. Change in plume dynamics due to each parameter has been discussed in detail with the help of in-cylinder soot contours. A reentrant bowl with a higher swirl, lower number of nozzle holes and a deeper spray angle has been found to be the most promising option as it reduces the exhaust soot mass, number density with no penalty on NOx and specific fuel consumption.

Research on geometrical parameters effect of fan nozzle jet performance based on orthogonal experiment

In order to determine the significance and importance order of the jet performance caused by fan nozzle's geometric parameters of aero-engine online cleaning equipment, the orthogonal experiment method, standard k–ɛ turbulence model and volume of fluid (VOF) two-phase flow algorithm are used to research the jet of fan nozzle. The sensitivity of nozzle contraction angle, nozzle area ratio, nozzle incision angle, nozzle exit thickness and offset to the influence of fan nozzle spray angle was verified by range analysis and variance analysis. The results of the two analysis methods consistently show that the main order of influence of the geometric parameters of fan nozzle on spray angle is nozzle area ratio, nozzle incision angle, nozzle exit thickness, offset and nozzle convergence angle. The former two have more influence on the spray angle than the others. Finally, the simulation results and orthogonal test results are verified by the injection experiment of the fan nozzle. The jet shape is mainly determined by the nozzle area ratio and incision angle. The larger the incision angle and the nozzle area ratio are, the smaller the spray angle becomes.

Numerical Investigation of Heat and Mass Transfer Inside a Wet Cooling Tower

This paper presents a numerical investigation of heat and mass transfer inside a wet cooling tower with forced air draft, which find application in energy process industries and oil refineries. The mathematical model consists of mass, momentum and energy conservation equations, water droplet trajectories and their interaction with the gas phase, the computational domain and boundary conditions. Numerical distributions of air velocity, air temperatures, water vapor fractions and evaporation rates are shown and discussed. The wet cooling tower achieves an efficiency of around 80%, which can be improved by optimizing the value of the water droplet size, nozzle spray angle and water-to-air flow rate ratio. The water droplet size has a dominant effect on the cooling tower efficiency, whereas small droplets improve the efficiency up to 10%. On the other hand, the spray angle and the water-to-air ratio lead to slight improvements, about 2-3% in the best case.

Hard machining performance of indigenously developed green cutting fluid using flood cooling and minimum quantity cutting fluid

Cutting fluids play a vital part in turning process. Basically, these cutting fluids are made up of mineral oil (MO) and performance enhancing additives that are produced chemically. However, MO has adverse environmental effects and causes health hazards. Therefore, MO is gradually replaced by green cutting fluid (GCF). Indigenously developed environmental friendly vegetable based GCF with minimum quantity cutting fluid (MQCF) application technique can serve as a viable solution to make current work a cleaner process. In this present study, vegetable-based GCF was synthesised and characterized. Emulsion stability and anti-corrosion properties of GCF were investigated. MQCF machining process parameters such as cutting fluid emulsion composition, nozzle stand-off distance and nozzle spray angle were experimentally optimized to extract better output. Hard machining experiments were performed with developed GCF using flood cooling (FC) and MQCF techniques during turning of hardened AISI H-13 steel. For comparison, dry machining experiments were also carried out. Cutting force, feed forces, centre line average (CLA) surface roughness of workpiece were measured and the coefficient of friction was calculated. After machining, cutting tool rake face morphology and wear characteristics were studied using field emission scanning electron microscope, optical microscope and non-contact 3D surface profilometer. Result shows that cutting force, feed force, coefficient of friction and CLA surface roughness of workpiece were reduced using optimized MQCF process parameters. Also, machining performance was improved with MQCF technique using GCF as compared to flood cooling and dry machining.

Optimisation of injection-related parameters using the non-linear programming by quadratic Lagrangian algorithm for a marine medium-speed diesel engine

The match of an injector with the combustion chamber was studied through computational fluid dynamics simulation under four different engine loads. Four design parameters including the start of injection, spray angle, injector protrusion length and swirl ratio were examined. The Latin hypercube together with a non-linear programming by quadratic Lagrangian algorithm were used in the optimisation. Comparisons were made in the engine loads in terms of the optimisation history, objectives, sub-objectives and design parameters. The commonalities of the design parameters of the optimums were summarised. Additionally, a detailed combustion process comparison was conducted on the same engine loads (100% and 25% engine loads) between the optimum and baseline designs, respectively. Finally, the effects of the design parameters on the objective were investigated by the response surface methodology. The results indicate that the non-linear programming by quadratic Lagrangian method is an effective algorithm to spot the optimums with the best trade-off between nitrogen oxides and soot emissions. The optimisation process presents better qualities at 100% and 75% engine loads than in the case of 50% and 25% engine loads. The design parameters of the optimum under each engine load have something in common, namely, that they all prefer late injection, low swirl, large injection angle and slightly smaller nozzle protrusion length. Besides, start of injection and swirl ratio have larger influence on the objective as opposed to the nozzle protrusion length and spray angle. The large start of injection together with the small swirl ratio can reduce the objective significantly and vice versa. A large nozzle protrusion length with a small spray angle contributes to the reduction of the objective and so does the combination of a small nozzle protrusion length with a large spray angle.

Characteristics of intersecting airflows in the narrow flow channel

Air-jet loom is a kind of shuttleless loom, which is widely used in textile industries. The weft insertion system is composed of main nozzle, auxiliary nozzles, and profiled dent groove. The jets from the main and auxiliary nozzles intersect in the profiled dent groove. The velocity and stability of the intersecting airflows have a direct impact on the yarn’s motion. In this paper, the commercial software is adopted to simulate the intersecting airflows in the profiled dent groove. The result shows it is reasonable that the distance from the main nozzle to the first dent is 15 mm. The optimal distance from the main nozzle to the first auxiliary nozzle is between 45 and 50 mm based on the criteria of the utilization efficiency of the airflow. According to the standard of airflow stability, when the spray angle of auxiliary nozzle is about 7°, the standard deviation of the radical airflow velocity is the smallest in different cross sections. Therefore, the intersecting airflows are the most stable when the spray angle of auxiliary nozzle is about 7°. The velocity distribution of intersecting airflows in the profiled dent groove is measured using Particle Image Velocimetry (PIV) technique. The research results can provide some useful references for the optimization of the weft insertion system of the air-jet loom.

A characteristic study and optimization of in-cylinder configuration for particulate matters reduction in an off-highway diesel engine with mechanical fuel injection system

This paper shows development challenges for 11-liter heavy-duty off-highway diesel engines to meet Tier 3 emission regulations with a base diesel engine compliant with Tier 2 emission regulations. In the case of the installation of an exhaust gas recirculation (EGR) system for reduction of NOx emissions, there exists a risk of increased particulate matters (PM) emissions. An in-cylinder PM reduction is still necessary since a diesel particulate filter (DPF) after-treatment system is not under the consideration. The objective of this research is to see whether the base engine has a potential to meet Tier 3 emission regulations by changing in-cylinder configuration parameters including the bowl shape, injector position, the number of intake and exhaust valves, injector tip protrusion, and injector tip specifications such as nozzle spray angle and nozzle flow rate. These parameters are very important parts which enhance the air and fuel mixing process that helps the combustion process. Thus, the optimization of these design variables is essential to improve combustion efficiency and emissions reduction. In this study, the multi-dimensional computational fluid dynamics (CFD) code KIVA-3V is used to perform combustion simulations. The Kelvin–Helmholtz/Rayleigh–Taylor (KH-RT) model is employed for spray breakup and a reduced chemical mechanism for n-heptane is employed to simulate ignition delay and combustion of diesel fuel. To verify the simulation results, engine bench tests were performed with installations of the final version of in-cylinder geometry in C1-8 mode which is one of main test cycles to meet Tier 3 emission regulations. Finally, Tier 3 emission regulations have been met with the currently optimized in-cylinder configuration parameters.

Study of the generated density of cavitation inside diesel nozzle using different fuels and nozzles

A comparative study using different fuels and nozzles has been conducted focusing on the generated density of cavitation inside diesel nozzle. In this paper a visualization experiment has been carried out and the new parameters are presented to compare the effect of the injection conditions (including injection pressure, the spray angle of nozzle, the length–diameter ratio of nozzle orifice and the fuel type) on the generated density of cavitation. The research results indicate that the generated density of cavitation is sensitive to the change of injection conditions. The generated density increases about 10% for every 10MPa in injection pressure. The generated density increases with the increase of nozzle spray angle and with the decrease of length–diameter ratio. The cavitation appears early and changes fast by using the fuel with lower viscosity and higher saturated vapor pressure. The generated density of cavitation increases with the increase of saturated vapor pressure and decreases with the increase of viscosity.