Water Jet Process Research Articles

Experimental studies on penetration process of high-speed water-jet into ballistic gelatin

To reveal the penetration mechanism and present the penetration characteristics of high-speed micro-jet with injection volume larger than 0.3mL into soft tissue, the present study conducted experimental research on high-speed water-jet penetration into ballistic gelatin. The free jet dynamics of an air-powered needle-free injector that can emit up to 1.27mL of liquid at once and the penetration dynamics were visualized to reveal the details of the penetration process. In the early unstable stage, the jet is emitted in the form of pulses, and the first jet pulse can rapidly generate an initial slender channel in gelatin in a very short time. In the subsequent stable stage, energy input produces dispersion and further increases the penetration depth slowly. Changing the driving pressure by the power source mainly changes the penetration depth increment by dispersion; while changing the nozzle diameter mainly affects the penetration depth in the initial stage. The central position of the dispersion area in the injection direction was firstly defined in the present work and it was found that an approximate linear relationship between this position and the maximum penetration depth exits for different nozzle diameters and driving pressures when injecting the same liquid dose. These research results can provide a basis for a thorough understanding of the penetration characteristics of high-speed micro-jet with injection volume larger than 0.3mL into soft tissue, as well as the design and operation of the air-powered needle-free injector.

Experiments of Main Parameters Affecting the Erosive Behavior of Self-Excited Oscillating Abrasive Water Jets: Length of Self-Oscillation Chamber, Jet Pressure, Abrasive Fluid Velocity, and Abrasive Grain Size.

To enhance the erosion efficiency in traditional abrasive water jet processing, an abrasive water jet processing method based on self-excited fluid oscillation is proposed. Traditional abrasive water jet methods suffer from reduced jet kinetic energy due to the presence of a stagnation layer, which hinders efficient material removal. By integrating a self-oscillation chamber into the conventional abrasive water jet nozzle, the continuous jet is transformed into a pulsed jet, thereby increasing the jet velocity and enhancing the kinetic energy of the process. This modification aims to improve material removal efficiency. Using Ansys Fluent, we simulated the material removal efficiency on workpiece surfaces with varying lengths of self-oscillation chambers. The simulation results reveal that the optimal length of the self-oscillation chamber for maximum erosion is 4 mm. SiC materials were used to evaluate the impact of self-oscillation chamber length (L), jet pressure (P), abrasive flow rate (M), and abrasive grain size (D) on erosion. Experimental results show that the self-oscillation chamber increases erosion depth by 33 μm. The maximum erosion depths recorded were 167 μm when L = 4 mm, 223 μm when P = 16 MPa, 193 μm when M = 80 g/min, and 268 μm when D = 2000 μm. Overall, the self-excited oscillation effect enhances the erosion efficiency of the waterjet by 14%. This study further elucidates the factors influencing erosion behaviors in oscillating abrasive water jet processing.

워터젯 로봇의 가공 전용 치구 제작 공정 개선 및 평가에 관한 연구

Water-jet robots find application across various domains, including cutting, cleaning, and drilling diverse materials. Recently, they have been integrated into automated process lines for manufacturing automobile interior components. Consequently, with the advancement of water-jet robot processing technology, a dedicated fixture is required to support the product shape for processing complex-shaped automobile interiors. The existing water-jet processing fixtures were produced through a wet lay-up process using glass fiber to reduce manufacturing costs; however, recently, water-jet fixtures employed in automated lines have experienced deformation over prolonged usage, resulting in shape-processing errors and an increased the defect rate. Therefore, this study explores the use of carbon fiber and the VARTM vacuum bagging process to enhance the quality of water-jet dedicated fixtures, refine the manufacturing process, alleviate shape strain, and bolster the structural integrity of the fixtures compared to the conventional wet lay-up method typically employed for composite fixtures. A study was conducted on.

Study on water jet stability and processing morphology of groove cutting using water jet guided laser

In order to reveal the formation process of straight grooves using water jet guided laser (WJGL) technology and analyze the reasons for the formation of straight groove morphology, the stability of water jet in the straight groove were studied and the internal morphology of the straight groove obtained by WJGL processing was characterized. Firstly, the stability of water jet moving in straight grooves with different depths (0.5–50 mm), lengths (1–20 mm), widths (0–200 μm), inlet velocity (100–300 m/s), bottom shapes (flat, inclined), and types (through grooves, blind grooves) were studied through numerical simulation. Subsequently, the influence of water jet stability on the removal of material from the groove bottom was analyzed based on the guiding effect of water jet on laser. Then, different types of straight grooves (long blind groove, long through groove, short blind groove, short through groove) were processed using WJGL technology with different cutting cycles (2–10 times), and the internal morphology of the grooves was characterized through industrial computed tomography (CT). Finally, the reasons for the formation of the morphology inside the groove were analyzed based on simulation and experimental results. The results indicate that the fracture of the water jet in the blind groove includes when the water jet moves to the side wall, when the water jet reaches a stable length, and when the liquid is discharged from the narrow groove. The phenomenon of “inclined propagation” occurs when WJGL passes through the intersection of the flat and inclined bottom surfaces of the groove. The phenomenon of “inclined enhancement” occurs when WJGL is used to process the inclined bottom surface of the groove. This article reveals for the first time the flow morphology of micro water jet in straight grooves, and analyzes the reasons for the formation of groove morphology, which has guiding significance for the process optimization and practical application of WJGL technology in straight groove processing.

Effect of Leading-Edge Erosion on the Performance of Transonic Compressor Blades

In this paper, an experimental and numerical investigation of the effect of leading-edge erosion in transonic blades was performed. The measurements were carried out on a linear blade cascade in the Transonic Cascade Wind Tunnel of DLR in Cologne at two operating points with an inflow Mach number of 1.05 and 1.12. The numerical simulations were performed by ANSYS Germany. The type and specifications of the erosion for the study were derived from real engine blades and applied to the leading edges of the experimental cascade blades using a waterjet process, as well as modeled in detail and meshed within the numerical setup. Numerical simulations and extensive wake measurements were carried out on the cascades to evaluate the aerodynamic performance. The increase in losses was quantified to be 4 percent, and a reduction in deflection and a rise in pressure were detected at both operating points.

INTELLIGENT MODELS FOR CONTROL OF JET HYDRO-PROCESSING OF ROLLED STEEL DEFECTS

The structure of an intelligent control system for the hydro-processing of surface defects in rolled products is presented, which corresponds to the concept of the European program "Industry 4.0" in the direction of energy saving and total automation of processes.
 The considered local RBNN hydro-processing models are tuned using the Kaczmarz-Widrow-Hoff algorithm. The model for identifying the current task of the pressure of the processing fluid takes into account the relationship between the thickness of the processed defect, changes in the composition of the working fluid and, as a result, its abrasive properties. To form a given pressure in the corresponding jet, the following neural model estimates the duration and polarity of the voltage that controls the electric drive of the jet control valve in real time.
 The small-dimensional models’ conveyor is a promising solution for controlling waterjet processing of metals in such areas as rounding sharp edges; grinding and polishing complex surfaces; deburring and cleaning of welds; surface preparation for coating; removal of defects from the surface; high-precision waterjet cutting of metals. The solution will increase the speed of TP from 1.2 to 1.96 [m/s]. Taking into account the small dimensions of the models and the relatively low speed of the TP, a software application based on the proposed models can be implemented in the control system for the hydro-processing of rolled metal products in the form of an inexpensive IIOT microcontroller module.

A comprehensive study of diverse techniques for enhanced physicochemical and structural properties of bio-calcium from hybrid catfish bone

This research examined the impact of various comparative preparation methods on enhanced physicochemical, and structural properties of bio-calcium (BC) from hybrid catfish bone. Raw hybrid catfish bones (RB) were used to make bio-calcium in four steps. High-pressure water jet processing produced washed bone (WB), soaking the bone in an alkaline solution to remove proteins (PR), immersing it in ethanol to remove lipids (LR), then bleaching, and grinding it to make bio-calcium powder. The BC had greater lightness values (L*) (p < 0.05), and contained significant calcium, and phosphorus. The SDS-PAGE showed three significant protein bands with molecular weights of 250, 133, and 116 kDa. The crystalline structure of hydroxyapatite in BC was confirmed using X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The percentage of crystallinity of BC had a notable rise, increasing from the RB to BC of 36.25%–45.32%. The BC powder exhibited a consistent distribution of particle sizes, ranging from 2 to 10 μm. Additionally, the analysis of elemental profiles, and mappings using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) revealed that BC exhibits a significant concentration of calcium, and phosphorus. BC showed superior %bioavailability of calcium (18.94%) in an in vitro simulated gastrointestinal system (GIMs) compared to RB (10.58%), and calcium carbonate (11.19%). Hence, the BC production process proved to be a viable method for acquiring premium-grade BC, which holds potential for further development as a calcium dietary supplement.

Characterization and optimization of abrasive water jet machining parameters of aluminium/silicon carbide composites

Due to the complexity of high temperature and cutting tool wear, most machined components are still facing problems in terms of harder functional fillers that reinforce aluminium matrix composites. Conversely, abrasive water jet machining (AWJM) incredibly useful for the cutting of anisotropic and non-homogeneous metal matrix composites. In this research article, silicon carbide (SiC) particulates were utilized as reinforcement in the AA6026 matrix material (AA6026/SiC) and machined using AWJM under different process parameters namely SiC loading, traverse speed and stand-off distance. Two different compositions of SiC (4, and 8 wt%) were considered to fabricate AA6026 composites using the stir casting. In addition, outputs have been examined, e.g., surface roughness, material removal rate, and kerf angle. An optical microscope, scanning electron microscope, Brinell hardness tester and universal testing machine have been used to characterize the matrix material AA6026 and its composites. Microstructural analysis revealed that the inclusion of SiC particulates in AA6026 affects the very fine grain size of the composite. Furthermore, the 8 wt% composite exhibits the evolution of the Al-Si eutectic phase during solidification. Processing of these composites was performed using the L27 orthogonal geometry, successfully improving the parameters of the abrasive water jet process. The output response shows that reducing the SiC load improves the surface roughness under the key parameters of traverse speed and stand-off distance. However, increasing the SiC loading increases the material removal rate and kerf angle under the key parameters, namely traverse speed, and stand-off distance.

Optimization of the Morphology of the Removal Function for Rotating Abrasive Water Jet Polishing.

Abrasive water jet polishing has significant advantages in the manufacturing of complex optical components (such as high-slope optical component cavities) that require high-precision manufacturing. This is due to its processing process, in which the polishing tool does not make direct contact with the surface of the workpiece, and instead maintains a considerable distance. However, the removal functions of most existing abrasive water-jet polishing technologies do not possess strict symmetry, which significantly impacts the ability to correct surface figure errors. Therefore, this study implements rotating abrasive water-jet polishing based on traditional abrasive water jet processing to optimize the removal function, which turns it into a Gaussian form; thus, obtaining a type of removal function more suitable for CCOS polishing. This paper derives an empirical formula between the distance s' from the peak removal point of the removal function to the stagnation point and the nozzle tilt angle α, based on geometric relationships and experimental results, analyzes the relationship between material removal efficiency, nozzle tilt angle, and standoff distance. Finally, this paper verifies through experiments the validity of this empirical formula under different process parameters. Therefore, this study obtains the process conditions that allow rotating abrasive water-jet polishing technology to achieve a stable Gaussian form removal function, and the appropriate process parameters to be selected in conjunction with polishing efficiency; thereby, effectively improving the removal function's corrective ability and manufacturing efficiency. It provides theoretical support for the processing capability and process parameter selection of abrasive water-jet polishing technology, solves the problem of limited shaping capability of existing abrasive water jet tools, and significantly improves the manufacturing capability of high-end optical components.

Multi-performance optimization for AWJ drilling process in cutting of ceramic tile: BBD with EOBL-GOA algorithm

PurposeThe goal of this study is to determine the values of the process parameters that should be used during the machining of ceramic tile using the abrasive water jet (AWJ) process in order to achieve the lowest possible values for surface roughness and kerf taper angle.Design/methodology/approachIn the present work, ceramic tile is processed by the AWJ process and experimental data were recorded using the RSM approach based Box–Behnken design matrix. The input process factors were water jet pressure, jet traverse speed, abrasive flow rate and standoff distance, to determine the surface roughness and kerf taper angle. ANOVA was used to check the adequacy of model and significance of process parameters. Further, the elite opposition-based learning grasshopper optimization (EOBL-GOA) algorithm was implemented to identify the simultaneous optimization of multiple responses of surface roughness and kerf taper angle in AWJ.FindingsThe suggested EOBL-GOA algorithm is suitable for AWJ of ceramic tile, as evidenced by the error rate of ±2 percent between experimental and predicted solutions. The surfaces were evaluated with an SEM to assess the quality of the surface generated with the optimal settings. As compared with initial setting of the SEM image, it was noticed that the bottom cut surface was nearly smooth, with less cracks, striations and pits in the improved optimal results of the SEM image. The results of the analysis can be used to control machining parameters and increase the accuracy of AWJed components.Originality/valueThe findings of this study present an innovative method for assessing the characteristics of the nontraditional machining processes that are most suited for use in industrial and commercial applications.

Feasible study on the sustainable and clean application of steel slag for abrasive waterjet machining

The rapid development of the global steel industry has led to a surge in steel slag. The resource utilization of steel slag has become a hot research topic in the solid waste industry. In this study, a new method of resource utilization of steel slag by replacing garnet with it for abrasive waterjet (AWJ) processing was presented for the first time. Typical brittle material marble and plastic material 6061 aluminum alloy were used as workpieces to evaluate the process performance of the method. The results show that the density, hardness, and surface shape of the steel slag meet the requirement of an ideal abrasive. Steel slag demonstrates comparable performance to the widely utilized garnet abrasive in terms of kerf width and roughness. Particularly, the cutting efficiency of steel slag per unit cost is more than 250% of garnet. Considering the price disparity between the two abrasives, the approach has the potential to reduce operational costs by 45% for AWJ factories, resulting in annual savings of approximately ¥60 million for the AWJ industry in China. Simultaneously, it holds the potential to save 1.549 × 105 GJ of energy and reduce 1.159 × 104 tons of CO2 emissions in the world annually.

Research Progress in Abrasive Water Jet Processing Technology.

Abrasive water jet machining technology is an unconventional special process technology; its jet stream has high energy, and its machining process is characterized by no thermal deformation, no pollution, high applicability, and high flexibility. It has been widely used for processing different types of materials in different fields. This review elaborates on the basic principles and characteristics of abrasive water jet processing, the mechanism of erosion, the simulation of the processing, the influence of process parameters in machining removal, and the optimization of improvements, as well as introduces the current application status, new technology, and future development direction of abrasive water jet technology. This review can provide an important information reference for researchers studying the machining processing of abrasive water jet technology.

Study on the process of abrasive water jet cutting for zirconia ceramic tubes

Study on the process of abrasive water jet cutting for zirconia ceramic tubes

High speed water droplet impact erosive behavior on dry and wet pulsed waterjet treated surfaces

During water droplet impact onto a dry or wet rough solid surface, several phenomena affect the surface erosion process, such as splashing, crown formation, and small droplet emission to name a few. These phenomena have been extensively studied for various simple target surface geometries. However, droplet impact studies on complex irregular and asymmetric target surface topographies resulting from a waterjet treatment have never been conducted. Furthermore, very limited reports are found on the role of target surface topography and water droplet deformation development on the resulting target stress state. In the present study, high speed droplet impingements on surfaces exhibiting coarse topographical features associated with ultrasonic pulsed waterjet treatment are modeled to understand the underlying mechanisms causing erosion. Impacts on surfaces with various roughness values and water film thicknesses are modeled using a three-dimensional coupled Eulerian–Lagrangian approach. A detailed comparative analysis of the model with experimental ultrasonic pulsed waterjet erosion features and material loss is provided. It was found that the synclastic curvature of the modeled coarse surface features increases the shock wave's strength as many compression wavelets are simultaneously emitted at each water droplet contact location with the surface, resulting in concentrated high-pressure zones. The ultrasonic pulsed waterjet treated surface features and water film thickness also greatly influence the onset of water droplet splashing, subsequent finger, secondary droplet characteristics, and crown stability. According to the numerical results, strong splashing patterns and droplet breakup are generated and create high stress zones capable of accelerating surface erosion, explaining the enhanced performance of ultrasonic pulsed waterjet process.

Prediction and mechanism of surface evolution in high-pressure slurry jet micro-machining of channels

Recent advances in abrasive water jet (AWJ) processes have enabled controlled-depth micro milling for a variety of applications, such as micro fluidic chip manufacturing. However, AWJ micro milling can be difficult to control and its successful application requires judicious selection of the process parameters. Since the mechanics of the process have not been fully understood, prediction of the machined topography arising from a set of process parameters is difficult. The present work combines computational fluid dynamics, Lagrangian particle tracking, and a deformed geometry surface evolution technique into a comprehensive model that predicts the evolving shape of micro-channels milled on 6061-T6 aluminum plates using high-pressure abrasive slurry jet machining (HASJM). Requiring calibration using only a single channel centerline depth, the model could predict the machined profiles of micro-channels milled using multiple nozzle passes with less than a 2% error. The model was also used to investigate the underlying physics of the machining process. This allowed experimental observations to be explained in terms of the changes that occur, due to the evolving eroded shape, in stagnation zone size, particle ricochet behavior, secondary slurry flow, and local particle impact angles and velocities. Overall, the work shows that such models can not only very accurately predict evolving machined topography, but also be very useful tools to understand abrasive jet machining mechanisms which occur on time scales which are too brief to be directly observed experimentally.

Effect of pulsating water jet processing on erosion grooves and microstructure in the subsurface layer of 25CrMo4 (EA4T) steel

The erosion of 25CrMo4 (EA4T) steel was studied to determine the surface and subsurface damage due to the high-frequency impingement of water droplets using an ultrasonic droplet generator. The material under investigation is railway axle steel, where the pulsating water jet can be used as a surface treatment method to increase the fatigue resistance. The surface processing is related mainly to standoff-distance which was changed to explore the effect of pulsating water jet while the other parameters were kept constant. Surface and subsurface conditions of the material were analyzed by means of light microscopy, scanning electron microscopy and transmission electron microscopy. By altering the standoff distance, it is possible to investigate droplet impingement from the point of view of the pulsating water jet process for different purposes, such as for maximal erosion or for an increase of fatigue resistance by introduction of severe plastic deformation to the surface. The maximum erosion state was reached for a standoff distance of 35 mm when a crater depth of 750 μm and a width of 1500 μm was observed. The mild conditions, when only plastic deformation is reached occurred at a standoff distance of 21 mm. The occurrence of subsurface cavities in materials with higher hardness indicates a significant penetration ability of the periodic high-density action of water droplets at subsonic speeds.

Effects of different processes on characteristics and properties of bio‐calcium from hybrid catfish (Pangasianodon gigas × Pangasianodon hypophthalmus)

SummaryThe research was aimed to study the impact of various treatments on characteristics of bio‐calcium from hybrid catfish bone. Bio‐calcium from hybrid catfish bones (raw bone) was prepared using several 4 steps including high‐pressure water jet process (washed bone), soaking in alkaline solution (protein removal), ethanol immersion process (lipid removal), bleaching and grinding to obtain bio‐calcium powder. The obtained bio‐calcium had a yield of 14.46 g 100 g−1. Bio‐calcium had low protein, fat and moisture contents but had high ash content (P ≤ 0.05). Bio‐calcium was rich in calcium and phosphorus. Bio‐calcium contained high hydroxyproline content of 27.70 mg g−1 samples. Moreover, high contents of proline, glycine, aspartic acid alanine and glutamic acid were found in bio‐calcium. The ethanol immersion, bleaching and grinding process effectively decreased Thiobarbituric acid‐reactive substances (TBARS) values and total volatile acids (P ≤ 0.05) of bio‐calcium powder compared with washed bone, protein and lipid removal processes. Therefore, this research provided an alternative source for bio‐calcium production, which can develop as fortified in food products, calcium supplements and biomedical applications.

Full scale experimental and numerical simulation of outside transformer fire

To study the real scale transformer fire and fire control process, this paper uses FDS to simulate the transformer fire combustion process and analyzes the data of transformer fire temperature and flow field. Through data analysis, this paper establishes a fire visualization system based on the unity3d engine and uses modeling software to complete the Substation Scene Modeling, the visualization process of fire particles and fire water jet in the whole process of transformer fire occurrence and fighting is realized. The research results are of great significance for substation fire construction and emergency rescue.

Study the Effect of Cutting Parameters of Abrasive Water Jet Process on Aluminum Alloy 5083

Study the Effect of Cutting Parameters of Abrasive Water Jet Process on Aluminum Alloy 5083

Micro-machined deep silicon atomic vapor cells

Using a simple and cost-effective water jet process, silicon etch depth limitations are overcome to realize a 6 mm deep atomic vapor cell. While the minimum silicon feature size was limited to a 1.5 mm width in these first generation vapor cells, we successfully demonstrate a two-chamber geometry by including a ∼25 mm meandering channel between the alkali pill chamber and the main interrogation chamber. We evaluate the impact of the channel conductance on the introduction of the alkali vapor density during the pill activation process and mitigate glass damage and pill contamination near the main chamber. Finally, we highlight the improved signal achievable in the 6 mm silicon cell compared to standard 2 mm path length silicon vapor cells.