Jet Impingement Angle Research Articles

Experimental study on optimization of abrasive water jet process parameters

Abstract In order to improve the mining speed of coal mine roadway and fundamentally solve the problem of mining imbalance, the abrasive water jet technology is used to cut rocks in front of mechanical tools to achieve efficient improvement of coal mine roadway mining efficiency. Based on the existing high pressure pure water jet test equipment, the abrasive water jet test platform was built, and the uniaxial compressive strength of soft and hard rock was obtained by testing the rock mechanical properties. The effect of jet pressure, target distance, transverse velocity and jet impact Angle on rock cutting is studied by using control variable method. According to the single factor test analysis, L16 (44) four-factor four-level orthogonal test analysis table is selected to carry out orthogonal tests on granite and sandstone respectively. The results of range analysis and variance analysis show that the main and secondary relationships of abrasive water jet factors are as follows: transverse velocity > jet pressure > jet inclination > target distance. The optimal jet parameters are when jet pressure is 40 MPa, target distance is 5mm, transverse velocity is 2mm/s and jet inclination is 10°.

Investigation of droplet splashing behavior during oblique jet impact onto a wall

For the issue of jet impingement on the wall in industrial cooling processes, an experimental setup based on high-speed photography for oblique jet impingement onto the wall was constructed. The experimental focus was on the study of liquid droplet splashing behavior after oblique jet impingement on the wall, discussing the liquid droplet splashing behavior under three jet impingement modes: Rayleigh regime, first wind-induced regime, and secondary wind-induced regime. By employing methods such as trajectory imaging and particle image velocity for liquid droplet parameter image measurement, obtaining the particle size, velocity, and distribution of splashed droplets after oblique jet impact on walls under different working conditions. The impact of jet impingement velocity and angle on droplet splashing parameters was analyzed. The results showed that when the impingement point is before the breakup length, with increasing flow velocity, the surface wave of the liquid column, and the spreading liquid film became more pronounced, but the loss of liquid-phase components due to splashing was relatively small. When the impingement point is after the breakup length, the secondary breakup resulting in a “crown”-shaped liquid film after droplet impingement leads to a significant loss of liquid-phase components through splashing. As the inlet velocity of the jet increases, there is a decreasing trend in droplet size and an increasing trend in droplet velocity. With an increase in jet angle, there is a decreasing trend in droplet size and velocity. Based on the concentration, size, and velocity distribution characteristics of splashing droplets, the area after oblique jet impingement on the wall can be divided into the impingement zone, low-concentration low-velocity zone, high-concentration high-velocity zone, and lateral splashing zone. This has significant implications for understanding the splashing mechanism after oblique jet impingement on the wall and optimizing operating conditions.

An experimental investigation into the potential of employing mixed eco-friendly abrasives during AWJ milling of nickel-based superalloy

Non-conventional machining processes are capable of achieving higher performance compared to conventional ones due to their inherent characteristics and higher amount of parameters which can be favorably regulated. Although the correlation between the most important process parameters and process outcome has been already established for a wide range of conditions and workpiece materials, the introduction of new considerations related to the three pillars of sustainability require further investigation on new means for the enhancement of AWJ milling process. As one of the most important parameters in AWJ milling is the abrasive material, the introduction of new materials may offer considerable advantages from different perspectives. Thus, in the present work, a comprehensive investigation on the efficiency of using eco-friendly, mixed abrasives is carried out under various conditions such as different traverse feed rate, abrasive mass flow rate, water jet pressure, jet impingement angle, and mixing ratio. The feasibility of using mixed abrasives is evaluated in terms of achievable depth of penetration, kerf width, kerf taper angle as well as material removal rate (MRR), and cutting efficiency. The findings indicate that among other factors, the mixing ratio plays a noticeable role especially regarding MRR and cutting efficiency and can offer an additional effective means to achieve the desired kerf characteristics in conjunction with other significant parameters such as water jet pressure.

A Study on the Optimization of Water Jet Decontamination Performance Parameters Based on the Response Surface Method

The substrate that adheres between the teeth of the traveling track plate during the operation of a deep-sea polymetallic nodule mining vehicle affects the driving performance, so this study aimed to investigate the effect of the water jet on the cleaning and decontamination performance of the track under different conditions. An optimization design method based on response surface methodology (RSM) is proposed. Based on the Box–Behnken design, the optimization variables of jet pressure, jet target distance, and impact angle, and the target response of jet strike pressure on tracks, were selected, and the numerical simulation method was combined with the response surface method to establish the regression model of the response of each optimization variable to the jet strike pressure on tracks and to determine the optimal parameter combinations. The study findings indicate that the primary factor influencing the pressure of the jet striking the crawler is the jet pressure. The hierarchical order of influence on the pressure of the jet striking the crawler, under the interaction of the three factors, is as follows: jet pressure and impact angle, jet pressure and target distance of the jet, and target distance of the jet and impact angle. The maximum pressure of the jet striking the crawler occurs when the jet pressure is 0.983 MPa, the target distance is 0.14 m, and the impact angle is 89.5°. Overall, the proposed design serves as a systematic framework for parameter optimization in the cleaning and decontamination process, and the research method and results provide theoretical references for the optimal design of mining truck desorption efficiency, which is critical for increasing mining efficiency and lowering energy consumption.

Experimental Study of Sediment Erosion in Pelton Turbine Bucket

Abstract In hydroelectric power plants (HPPs), sediment-laden water flows through entire turbines, causing components to be damaged over time. Pelton turbine components serve abrasive erosion from particle hardness, and rough surface when subjected to high flow velocities and various jet impingement angles. In this study, an experiment was conducted to examine the erosion-prone areas of a small-scale Pelton turbine bucket under actual flow conditions. For the experiment, the Pelton bucket was painted with four distinct layers of paint: red, yellow, green, and blue. These layers served as indicators, helping us to visually track the erosion process. The setup was specifically designed to inject sediment upstream of the nozzle. It operated for a significant period of 0- 30 minutes, and every 5 minutes, the erosion pattern was noted with the nozzle fully open at 10 l/s and a net head of 6m with jet impingement angle 75°, 90°, and 105°. After operating for 0-30 minutes in sediment-laden flow conditions, a pattern of erosion was revealed, showing the hot spots (areas more susceptible to erosion) during the investigation at jet angles of 75°, 90°, and 105°. The most severe erosion areas are in the bucket domain, specifically at the splitter region and the deeper upper and lower parts of the brim. The erosion mechanism was influenced by the jet diameter and impingement angle on the bucket splitter. The experiment revealed that the outer regions of the bucket, where the flow was directed outward, suffered the most severe erosion, providing evidence of particle separation at high accelerations.

Characterization of RF-Sputtered ZnO Thin Film Coatings on Aluminum (Al6061): Microstructure, Wettability, Cavitation, and Corrosion Analysis

The study focuses on the characterization of Aluminum (Al-6061) coated with RF-sputtered Zinc Oxide (ZnO) thin film, aiming to understand the complex interactions between microstructure, wettability, cavitation resistance, and corrosion performance. The study involves the use of various analytical techniques such as Field Emission Scanning Electron Microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and water contact angle (WCA) measurements. The cavitation erosion testing has been conducted under various factors namely jet velocity (m/s), impingement angle (°), and stand-off distance (cm), respectively, and that too at various levels. Further, with the use of RSM, the study also contributes to the interplay in between factors and acquiring optimized results. Moreover, the findings of the study provide valuable insights into the effectiveness of the ZnO coating in enhancing corrosion resistance and reducing mass loss due to cavitation erosion. The study’s results offer significant implications for the engineering and design of protective coatings for Aluminum surfaces, with the potential to enhance durability and performance in various industrial applications.

Microstructure, wettability, cavitation and corrosion performance of aluminum (Al6061) coated with RF-sputtered AlN thin film

This study addresses the challenge of enhancing aluminum substrates with AlN coatings for improved durability. Novel RF-sputtered AlN coatings were developed, demonstrating deposition with equiaxed crystals and a predominant presence of aluminum and nitrogen. The coatings exhibited hydrophobic properties as shown by contact angle measurements. Cavitation erosion resistance was systematically analyzed, revealing optimal parameters for minimizing mass loss, including jet velocity, impingement angle, and stand-off distance, thereby showcasing the protective role of the RF-sputtered AlN coating. Response Surface Methodology (RSM) provided insights into the correlation between operational parameters and mass loss, leading to process optimization with specific mass loss values and high desirability percentages. XPS analysis of corroded AlN on Al-6061 revealed aluminum compounds, sodium, NaCl, and oxidation products, aligning with SEM/EDS results and confirming the coating's effectiveness in mitigating corrosion. Carbon and oxygen were the most abundant elements by weight and peak area. Overall, this study offers valuable insights into the multifaceted performance and protective capabilities of RF-sputtered AlN coatings.

On the radial interface profile of the non-circular hydraulic jump

The radial interface profile of the non-circular hydraulic jump is analyzed based on the time-averaged film thickness profile of the liquid film formed by a round jet obliquely impinging on a horizontal plate. The influence of many factors, including the jet velocity, impingement angle, azimuthal angle, liquid viscosity, and surface tension, on the radial interface profile is considered. The interface profile is like a quasi-spherical crown when the azimuthal angle is small but is like a sewing needle when the azimuthal angle is larger than 100°. Six parameters, including the inner and outer tangential angles, width, maximum thickness, radial position of maximum thickness, and area are defined to describe the interface profile. Then, six empirical equations are developed to fit the variation of the six parameters. As the azimuthal angle increases, the inner tangential angle decreases, but the outer tangential angle increases. As the jet velocity increases to 20.3 m/s, both the maximum thickness and the area increase suddenly. All empirical equations have a prediction accuracy of about 10%, except for the empirical equation of the radial position of maximum thickness. The bubble trajectory indicates that the liquid flows radially in the thin-layer zone, deflects the flow direction within a relatively short distance in the inner half of the non-circular hydraulic jump, and then flows tangentially. The normal bulk velocity in the radial section of the non-circular hydraulic jump increases from zero at first and then decreases as the azimuthal angle increases.

Numerical Analysis of Convective Heat Transfer in Quenching Treatments of Boron Steel under Different Configurations of Immersed Water Jets and Its Effects on Microstructure

In this work, the effects of jet impact angle and water flow on the heat-transfer coefficient in boron steel probes were analyzed. Angles of 90°, 75° and 60° were used with stirring flows of 33 l·min−1, 25 l·min−1, 13 l·min−1 and 6 l·min−1. The aim consisted of determining the heat-extraction rates by analyzing the correlation programmed in the Ansys Fluent 2020R2 software when different cooling conditions are used, avoiding many experiments, and establishing quenching conditions free of surface defects on the workpiece. This process is currently used in heavy machinery, requiring high hardness and wear resistance. The fluid-dynamic field was validated using a scale physical model using the particle image velocimetry technique, PIV. In contrast, the thermal field was validated with transient state experiments solving the inverse heat conduction problem, IHCP. The results show that for high flows (33 l·min−1), the jets with an angle of 90° impact the entire surface of the piece, but their cooling rate is slower compared to the other angles, being 243.61 K·s−1, and 271.70 K·s−1, 329.56 K·s−1 for 75° and 60°, respectively. However, for low flows (6 l·min−1), the impact velocities are very similar for the three cases, promoting more homogeneous cooling rates of 58.47 K·s−1, 73.58 K·s−1 and 63.98 K s−1 for angles of 90°, 75° and 60°, respectively. Likewise, through the use of CCT diagrams, it was determined that regardless of the cooling rate, the final structure will always be a mixture of martensite–bainite due to the effect of boron as determined experimentally, which implies a more significant proportion of martensite at higher cooling rates.

Study on the film thickness and surface wave velocity of the thin liquid film formed by a round jet obliquely impinging on a horizontal plate

For a thin liquid film (in a supercritical flow) prior to the formation of a non-circular hydraulic jump formed by a round jet obliquely impinging on a horizontal plate, the time-averaged film thickness and the surface wave velocity are extracted based on the measured transient film thickness. On the one hand, the effect of many factors, including the jet velocity, impingement angle, azimuthal angle, liquid viscosity, and surface tension, on the time-averaged film thickness and surface wave velocity are discussed. When the jet Reynolds number increases to about 1.4×104, the film thickness profile suddenly increases, and the transition of liquid flow from laminar to turbulent occurs. Meanwhile, a rapid increase is observed downstream of the turbulent film thickness profile. The influence of surface tension on the time-averaged film thickness and surface wave velocity is negligible for thin liquid films before non-circular hydraulic jumps. Nonetheless, the surface tension has a significant influence on the interface profile of non-circular hydraulic jumps. Furthermore, a “crescent” kink region upstream of the jump can be identified when the surface tension is lower than 40.6 mN/m. On the other hand, experimental results are used to verify the prediction accuracy of existing approximate solutions. The laminar approximate solution with a quadratic boundary layer velocity profile can accurately predict the film thickness distribution of most laminar thin liquid films, except downstream of the thin liquid films with a dynamic viscosity higher than 9.71 mPa s. The surface wave velocities are found to be close to the predicted surface velocities of the approximate solutions.

Effect of pineapple leaf and ramie fiber length and weight percentage on the hybrid polymer composites dry sliding wear and air jet erosion studies

AbstractIn this work, pineapple leaf fiber (PALF) and ramie hybrid fiber‐reinforced epoxy composite samples were evaluated for their hardness strength and resistance to dry slide wear and air jet erosion. Primary reinforcement using the hybrid material was chosen from different lengths (10, 15, 20, and 25 mm) and weight percentages (10%, 20%, 30%, 40%, and 50%). The hardness strength of the hybrid composite varied from 74 to 97 Shore D hardness strength. A dry sliding wear test was conducted with the key parameters of load (20, 30, and 40 N), time (20, 10, 7 min), and speed (160, 320, and 479 rpm). By using the data analyzing software, Taguchi optimization method, the key contribution parameters were identified. In the air jet erosion experiment, impact angle (45°, 60°, and 90°), erodent velocity (28, 41, and 72 m/s), and discharge rate (1, 2.5, and 3.3 g/min) parameters were used. Fiber and matrix materials agglomeration effect and bonding behavior were identified by using the scanning electron microscope (SEM) images. The 20 mm length with 30% of the PALF and ramie hybrid fiber‐reinforced composite sample achieved high hardness strength (97 shore D) and created a high resistance toward wear and erosion studies.Highlights Natural plant pineapple leaf and ramie fibers are mixed with an epoxy matrix. Used Taguchi analysis to determine the means and signal‐to‐noise ratios Different weight percentages of the PALF and ramie hybrid composites Dry sliding wear and air jet erosion studies are conducted. Individual parameter contributions were identified.

Determination and Application of Optimum Abrasive Mass Flow Rate of Abrasive Waterjet

Abrasive waterjet can be effectively used in cutting reinforced concrete (RC) piles. The cutting performance increases with abrasive mass flow rate, but as the abrasive mass flow rate increases, damage of abrasive particles also increases. Using optimum abrasive mass flow rate in cutting RC piles, which is determined by considering damage of abrasive particles, can improve cutting performance. In this paper, quantification of effect of abrasive waterjet parameters on cutting performance is simplified by using maximum kinetic energy as medium to relate abrasive waterjet parameters to cutting depth. The damage of abrasive particles during acceleration is related to mixing tube diameter, abrasive material properties and gradation, and is independent of pump pressure, water mass flow rate, transverse speed, standoff distance (SOD), jet impingement angle, and number of cuts. It is found that damage of abrasive particles leads to a reduction of effective kinetic energy used in cutting RC structures. The model for prediction of optimum abrasive mass flow rate is proposed by introducing coefficient of momentum transfer, which considers loss of kinetic energy during acceleration. The optimum abrasive mass flow rate calculated based on proposed model is then used in field test, which shows obvious improvement of cutting performance.

Rock-Breaking Characteristics of High-Pressure, Dual-Stranded Water Jets

Because of the unclear understanding of the characteristics associated with coupled rock breaking using multiple water jets, a numerical model combining smoothed particle hydrodynamics (SPH) and the finite element method (FEM) was established to investigate the rock-breaking capacity of a high-pressure, double-stranded water jet structure. The effectiveness of this model was verified through field experiments. The study further examined the specific energy required for rock breaking using the high-pressure double water jets and analyzed the effects of jet pressure, nozzle diameter, jet impact angle, and impact point spacing on rock-breaking volume. The results demonstrate that the rock-breaking ability of a high-pressure double water jets is better than that of a single water jet. When the impact angle of the high-pressure double water jets was 15° and the distance between impact points was 2.0 d, the rock damage effect was the best. By comparing the specific energies for rock breaking of a single water jet and a double water jet, it was concluded that the best rock-breaking nozzle diameter is 1.6 mm. Furthermore, an orthogonal testing approach was employed to determine the main and secondary factors influencing the rock-breaking energy of the high-pressure double water jet. The order of significance was found to be jet pressure > impact angle > impact point spacing > nozzle diameter. These findings provide valuable guidance and reference for application in the coal mining industry.

Application of a hybrid ANFIS with metaheuristic algorithms to estimate the aeration design parameters

Abstract Cavitation is a common and complex hydraulic phenomenon on the chute spillways and may cause damage to the structure. Aeration in the water flow is one of the best ways to prevent cavitation. To design an aerator, estimation of aeration coefficient (β), jet length (L/h0), and jet impact angle on chute (tanγ) are important in this study. The potential of a hybrid adaptive neuro-fuzzy interface system (ANFIS) with metaheuristic algorithms was investigated to estimate the required parameters to design an aerator. The ANFIS was combined with four metaheuristic algorithms, including differential evolution (DE), ant colony optimization (ACO), genetic algorithm (GA), and particle swarm optimization (PSO). Experimental data and dimensionless parameters were used to develop the proposed hybrid ANFIS models. Three statistical indicators, including root mean square error (RMSE), mean average error (MAE), and coefficient of determination (R2), were employed to compare the proposed methods with empirical relations. According to the statistical indicators, among the data-driven methods, the ANFIS–DE method had the best prediction in estimating β (RMSE = 0.018, R2 = 0.984, MAE = 0.013), L/h0 (RMSE = 1.293, R2 = 0.963, MAE = 1.082), and tanγ (RMSE = 0.009, R2 = 0.939, MAE = 0.007).

Semi-empirical model for the liquid fuel film formed by an oblique jet impinging on a curved wall

The operating conditions and the properties of the liquid have great effects on the shape and size of the liquid film and eventually affect the efficiencies of the atomization of alternative fuels, liquid jet impingement cooling, and equipment cleaning processes. The shape and size of the liquid film are dominated by the distance from the stagnation point to the liquid film edge(rmax). In this study, after deducing the thickness profile and the theoretical rather than the numerical solution of the initial velocity profile of the liquid film, a set of semi-empirical models about the shape, size of the liquid film, and the width of the raised zone formed by an oblique jet impinging on curved walls have been developed. In order to validate the theoretical model, a corresponding experiment has been developed, in which the jet velocities, impingement angles, liquid viscosity, surface tension, and radius of curvature have been included. The comparisons showed the theoretical results are in good agreement with the experimental data. The error for the location of the inner and outer border lines are less than 14.9% and 13.5%, respectively, except for the location in the upstream part of the film. And the effects of jet velocity, impingement angle, surface tension, dynamic viscosity, and radius of curvature were also theoretically discussed. The outer border line of the liquid film is dominated by the impingement angle and the impingement velocity, which affect the rmax exponentially and linearly, respectively. And the liquid viscosity and surface tension coefficient also affect the rmax approximately linearly. But the effects of the liquid viscosity and surface tension coefficient on the rmax are much less than the impingement velocity. The radius of curvature has little effect on the outer border lines and width of the raised zone when gravity is ignored.

Study on the Fracturing of Rock by High-Speed Water Jet Impact

Due to the opaqueness of rock and the limitation of detection technology, it is impossible to accurately describe the crack growth process and determine the law of rock breakage. Based on smoothed particle hydrodynamics and the finite element method (SPH-FEM), a numerical model for high-speed water jet breaking was established in this work to simulate the fragmentation process of rock impacted by a high-speed water jet, and to study the effects of different jet angles on the propagation of microscopic cracks inside the rock. Additionally, we further analyzed the jet impact angle on the microscopic crack propagation trend of the rock by applying confining pressure to the rock. Theoretical and experimental analyses showed that the inclination angle of the jet determined the direction of axial crack propagation in the tension-type center. When the inclination angle of the jet exceeded 20°, the ability of water jet erosion was insufficient, and the efficiency of rock fragmentation was low. However, in the range of 15° to 20°, the capacity of erosion was strong, lamellar crack propagation was obvious, and rock chip block spalling was easily produced. The impact of the water jet on the rock at varying angles under rock confining pressure will make the crack propagation direction deviate from the direction without confining pressure and gradually become parallel to the rock plane, thereby promoting unilateral crack propagation in the direction of water jet impact, making the rock more likely to produce unilateral rock chip spalling.

Study on the slurry erosion wear of polycrystalline diamond compacts for application in fluidic oscillators

Fluidic oscillator made of tungsten carbide, the core component of the fluidic hammer, has a significantly reduced service life under the erosion wear of drilling fluids with solid particles. Polycrystalline diamond composite (PDC) has the potential to solve this issue due to its extremely high hardness and wear resistance benefits. However, few studies on the slurry erosion wear of PDC have been reported. In this paper, a modified slurry erosion experimental device based on submerged abrasive water jets was used to study the erosion resistance of four grades of PDCs with grain sizes of 2–3, 5, 10 and 25 μm respectively. The erosion surface of the damaged PDC was observed by scanning electron microscope (SEM) and the erosive mechanism of the PDC was analyzed. The experimental results showed that PDC had excellent slurry erosion resistance. The erosion rate of PDC was 1/192–1/43 of that of tungsten carbide when the jet velocity was 100 m/s. The erosion rates of PDC increased with the rise of jet velocity, impact angle and erodent particle size. In addition, the erosion performance of debris represented by quartz to PDC is greater than that of weighting agents represented by barite and hematite. Further research also showed that PDC with fine grain has greater erosion resistance than PDC with coarse grain, except PDC2 ~ 3. At a high impact angle, the erosive mechanism was forming the craters due to the crushing of diamond grains and the pits due to the overall pullout of diamond grains, while at a low impact angle, the erosive mechanism was ploughing and forming directional craters.

Experimental investigation of the abnormal rise of water-wings downstream of a step-type aerator

Abstract In the prototype observation of a huge water conservancy project, flood discharge in the deep outlets showed strong fluctuations in the downstream of step-type aerators. Intermittent eruption and rise of the water-wing was observed, and the water-wing occasionally impacted on the structures above the chute. In order to investigate the mechanism of water-wing rise, model tests of the deep outlet have been conducted. High-speed camera, pressure sensors, and hot-wire anemometer are adopted to obtain the characteristics of cavity and water-wing. Several key parameters are measured, including air pressure in the cavity and air entrainment volume. It is found that variations of net cavity length, filling water length, and the height of water-wing rise increase with the angle ratio R, and a substantial jump occurs for all related parameters when R approaches 1.4. The rate of water-wing rise W is less than 10% for R < 1.4, while it suddenly increases to over 25% for R > 1.4. Correlations among inflow condition, jet impact angle, cavity deformation, pressure fluctuation in the cavity, and the rise of water-wing are studied, thus the underlying mechanism of abnormal rise of water-wing is proposed.

Flow characterization in the uphill region of pulsed oblique round jet

An experimental study to investigate the effect of jet pulsations on the wall jet development in the uphill region of an obliquely inclined round water jet has been performed using particle image velocimetry technique. The study has been performed at a constant nozzle to target wall distance, L/D = 4 (D is the diameter of the nozzle) by varying the jet impingement angle θ (=60o, 45o, and 30o), Reynolds numbers (ReD = 1900 and 3280; based on nozzle diameter and average nozzle exit velocity Uavg), and Strouhal number (0 ≤ St ≤ 0.9; St=fDUavg, where f is the frequency of external pulsation). It is observed that the pulsations have no significant effect on the jet in the free jet region when the target plate is kept at a distance less than the potential core length (the potential core extends up to 4D–6D from the nozzle exit toward the impinging plate), and the jet impingement region extends up to 1D from the plate. The location of the stagnation point is observed to depend on all three parameters: the jet pulsation, the Reynolds number, and the jet impingement angle. An increase in Reynolds number creates an adverse pressure gradient toward the downstream direction in the uphill region, resulting in an intrusion of ambient fluid toward the wall jet. The distance between the geometric center and the stagnation point is observed to be minimum for St = 0.44 at both the Reynolds numbers. The wall jet that develops in the uphill region exhibits a maximum velocity decay rate and a jet half width growth rate corresponding to St = 0.44. These parameters are also observed to increase with the increase in the Reynolds number and decrease in the jet impingement angle. The velocity fields reconstructed using proper orthogonal decomposition reveal the dominant modes in the upstream location for St = 0.44 than the other pulsations. Furthermore, we observed that the jet after impingement deviates entirely in the downhill region for θ=30o irrespective of the jet pulsation, suggesting a non-dependence of the critical angle of inclination on jet pulsations for L/D = 4.

A study on the effect of multiple abrasive particle impact on the crater sphericity in AWJM using FEA

The workhorse of the Titanium alloy industry i.e., Ti-6Al-4 V, is classified among the foremost widely utilized Titanium (Ti)-alloys and is broadly utilized in aviation and medication industry where low-density, supreme quality and exceptional erosion resistance are required. Since this material has high strength, it is very hard to process by means of conventional methods of machining. Therefore, unconventional machining methods like Abrasive Waterjet Machining (AWJM) become of great importance. Current work exhibits an explicit modelling of multiple abrasive particles impact on Ti-6Al-4 V in AWJM using Finite Element Analysis (FEA) approach. For experimental verification purpose, the crater geometry made on the Ti-6Al-4 V were determined and compared with the crater sphericity values obtained through FEA simulation. Also, the influence of velocity of abrasive particles and jet impact angle on sphericity of the crater was examined. For experimental verification of FEA simulations, the impact angle emerged as a key process parameter. The error between the simulation and experimental crater sphericity values was below 20%. It was also observed that the simulation results were accurate upto 0.04% for 90° impact angle and overall, the simulation model showed better results for 220 m/s abrasive particle velocity.