Objective The global greenhouse effect is escalating, leading to the progressive deterioration of ecosystems and climate worldwide. As the primary greenhouse gas, reducing CO2 emissions is crucial for effectively mitigating this effect. Fly ashu2013CO2 mineralization and sequestration technology represents a promising approach for carbon fixation and emission reduction. However, the low carbonation efficiency of fly ashu2013CO2 remains the central constraint hindering effective CO2 mineralization and sequestration. Thus, elucidating the microscopic mechanisms and key influencing factors of fly ashu2013CO2 carbonation is essential toward addressing this limitation. Methods To investigate these issues, a custom-designed setup was used to conduct experiments, including conventional immersion, immersionu2013carbonation, and microstructural characterization tests to examine the effects of immersion time on alkaline metal ion leaching and diffusion, as well as the impact of the microstructures of fly ash and CO2 on the carbonation efficiency. Results Results show that the pH increase rate exhibited a negative exponential decay relative to immersion time. After 24 hours of immersion, the carbonation efficiency and sequestration capacity reached peak values of 12.855% and 12.91 kg/t, respectively, representing a 0.25-fold increase over non-immersed fly ash. Raw, unmineralized fly ash contains amorphous silica (SiO2), mullite (Al2SiO5), and amorphous silica hydrate (SiO2u00B7xH2O). No diffraction peaks were detected for calcium carbonate, calcium hydroxide, or magnesium hydroxide, confirming the absence of calcium carbonate in the original sample. Conversely, the mineralized sample contained phases such as amorphous silica hydrate (SiO2u00B7xH2O), quartz (SiO2), mullite (Al2SiO5), calcium carbonate (CaCO3), and hydroxides (Ca(OH)2 and Mg(OH)2). The absence of the magnesite diffraction peak indicated that magnesium did not participate in the mineralization reaction. Furthermore, the observed low-intensity diffraction peaks were broad, indicating low sample purity and small crystal size, confirming the predominantly amorphous composition of the matrix. The diffraction-peak intensity of calcium carbonate initially increased and then decreased with increasing immersion time, with the maximum mass fraction (1.10%) observed at the 24-hour mark. Raw fly ash particles were spherical and dispersed. By comparison, the carbonated samples exhibited agglomeration and cementation, peaking at the 24-hour mark, with amorphous calcium carbonate deposited on the particle surface. Additionally, the carbon content of the carbonated fly ash increased with immersion time (within 24 hours), indicating a higher carbonation degree. The frequencies of larger and smaller particles increased and decreased, respectively, with the immersion time (u2264 24 h), suggesting positive and negative correlations between larger and smaller particles and the carbonation degree, respectively. Conclusions This study investigated the leaching and diffusion characteristics of fly ashu2013derived alkaline metal ions and their impacts on the microphysicochemical properties of fly ash, as well as their relationship with CO2 mineralization efficiency. Through a series of experiments involving fly ash immersion across different durations, followed by mineralization tests and microstructural characterization of the mineralized fly ash, the influences of soaking time on the leaching and diffusion behavior of alkaline metal ions were evaluated. Additionally, the effects of leaching on the microstructure of fly ash, as well as the efficiency of CO2 mineralization, were examined. Overall, these findings provide theoretical guidance for optimizing reaction parameters and enhancing mineralization efficiency in fly ashu2013CO2 mineralization processes.

An abrasive water jet (AWJ) has significant application potential in underground engineering. However, reports on the damage behavior of abrasives and high-pressure water on sandstone minerals are rare, and the coupled rock-breaking processes and mechanisms remain unclear. This study discusses the limitations of current AWJ simulation methods and the advantages of the material point method (MPM). Two realistic heterogeneous sandstone models were constructed, and AWJ experiments and numerical simulations were conducted. The stress transmission characteristics of the AWJ and the minerals’ damage behavior were elucidated, explaining the AWJ’s rock-breaking mechanism. The results showed the following. (1) The impact of abrasives caused stress concentration and mineral fracture, leading to shear failure. Stress wave diffusion resulted in energy transmission in the elastic region. The energy was dissipated when the material exhibited plastic damage. (2) The heterogeneity of materials and structures significantly affected the stress distribution. Minerals with higher mechanical strength responded more strongly to stress, and defects (pores, weak planes) in the rock became stress concentration regions during loading. (3) The water wedge effect caused weakness-driven failure. The cracks propagated along mineral interfaces or penetrated weaker minerals on the impacted surface. (4) The water wedge loosened minerals and created irregular fracture surfaces on the impacted face while applying sustained tensile forces. Thus, the abrasive particles efficiently removed the loosened material.

During hydraulic fracturing of layered reservoirs, the interaction among interlayer in situ stress differences, interfacial cohesion, and frictional properties governs whether hydraulic fractures penetrate the interface or induce interfacial slippage. However, traditional cohesive zone models struggle to accurately represent the dynamic coupling mechanism between interfacial friction and cohesion. To address this, a friction-cohesion element coupled with pore pressure was developed based on the finite element method and was then applied to three-dimensional fluid–solid coupled numerical simulations. A systematic study was conducted on the effects of in situ stress differences and interfacial mechanical parameters on the interaction between hydraulic fractures and interfaces, as well as on fracture propagation behavior. Additionally, the regulatory effects of fracturing parameters on the vertical propagation of fractures were further analyzed. The results indicate that the mechanical response of the interface is complex and diverse: the fracture initiation stage is dominated by shear failure, while the propagation stage exhibits two modes—a shear fracture mode and a mixed shear-tensile fracture mode. Under the combined influence of in situ stress differences and variations in interface friction and cohesion strength, five typical fracture patterns are formed. Among these, the “ ”-shaped fracture and penetrating fracture both significantly enhance the fracturing effectiveness of layered reservoirs. Further analysis reveals that increasing the viscosity and pumping rate of fracturing fluid facilitates the extension of hydraulic fractures along interfaces and promotes the development of complex fracture networks. However, increasing the pumping rate enhances cross-layer fracture propagation only under specific stress conditions. Furthermore, rapidly increasing the fluid pumping rate during the pad fluid stage also contributes to improved cross-layer fracture extension. In summary, this study provides theoretical and technical support for optimizing hydraulic fracturing in multi-interface layered reservoirs.

Abrasive water jet (AWJ) cutting can overcome the problems of large disturbance to surrounding rock, severe over‑ and under‑excavation, and tool wear associated with traditional rock‑breaking methods, showing great application potential in underground engineering development. However, the kerf response and deformation characteristics of AWJ-cut surrounding rock under in situ stress remain unclear. In this study, cutting experiments under in situ stress were conducted on two types of sandstone with different strengths. The effects of in situ stress, pump pressure, and cutting angle on the kerf response, deformation and pressure relief of the sandstone were analyzed. The results show that: 1) When the in situ stress increases from 5 to 25 MPa, the average cutting depth decreases by 8.86

Investigating rock behavior at the mineral scale provides critical insights into macroscopic failure mechanisms. This study developed a modular micromechanical modeling framework integrating mineral parameter characterization, three-dimensional (3D) digital core generation, and GPU-accelerated material point method (MPM) simulations to analyze granite under uniaxial compression. The framework uses nanoindentation tests, MPM simulations, and deep neural networks to determine mineral elastoplastic parameters. A convolutional neural network generates high-fidelity 3D digital cores representing mineral spatial distribution and geometry. The elastic modulus and uniaxial compressive strength derived from the numerical simulations and experimental results are in good agreement. The mineral’s spatial distribution and morphology significantly influence rock strength. The texture model, which preserves intergranular interlocking and heterogeneity, yields 13.4

This study proposed a deep learning-based nanoindentation simulation method to address the challenge of obtaining the mechanical parameters of rock-forming minerals and the complexity of regression analysis. This approach enables the accurate assessment of rock-forming minerals’ mechanical parameters. A material database of nanoindentation load-depth (P-h) curves was generated using the material point method (MPM) to characterize the mechanical behavior of major rock-forming minerals (quartz, albite, and muscovite) in sandstone. We used Bayesian hyperparameter optimization to determine the optimal hyperparameters for training a deep neural network (DNN). The trained DNN model accurately predicted the material parameters of rock-forming minerals using experimental nanoindentation P-h data. Numerical simulations of the uniaxial compression of heterogeneous sandstones were conducted using the predicted parameters to assess the sandstones’ macro-mechanical characteristics. The research findings provide new insights into the fundamental mechanical behavior of heterogeneous rock materials.

The interference of reservoir parameters during the multi-gas and multi-layer combined production of coal measure reservoirs seriously affect the efficient output of coal measure gas. In order to reveal the dynamic change laws and inter-relation of stress, reservoir pressure and fluid production during the multi-gas and multi-layered production process in coal measure reservoirs, a large-scale composite reservoir physical model (1 200 mm×1 200 mm×2 060 mm) containing two sandstone layers and two coal seams is innovatively designed based on the geological conditions of Linxing Block in Ordos Basin. A combined mining experiment of multi-gas and multi-layer in coal measure reservoirs was conducted utilizing the independently developed multi-functional physical simulation experimental system for deep coal and rock engineering. The dynamic gas production patterns of different production layers and interlayer flow interference among them were discussed, and the characteristics of stress transmission and reservoir pressure as well as their impact on adjacent layers were analyzed during the process of gas injection and gas extraction. The results show that during the combined production, the instantaneous gas production peaked and then decreased exponentially, with faster flow decay in sandstone layers during high-flow stages and in coal seams during low-flow stages. During the entire gas production stage, the instantaneous gas production rates of the four layers were observed to be higher in the sandstone layers than in the coal layers, and higher in the thick coal layers than in the thin coal layers. Increasing the flow rate of the sandstone layer would result in a decrease in the flow rate of the coal layer; while reducing the flow rate of the sandstone layer will cause an increase in the flow rate of the coal layer. This indicated that there was a significant inter-layer flow interference among the various production layers. During the combined production process, the decline in reservoir pressure and the rate of pressure decay in thick coal seam is lower than that in thin coal seam. Furthermore, when gas is injected into the sandstone layer, both the solid pressure of the sandstone layer and that of the coal layer will increase. Moreover, during the loading and unloading process, changes in the stress will significantly affect the variation of gas pressure. The research has revealed the interdependent relationships among stress, reservoir pressure and gas production volume during the multi-layered combined production of coal measure gas. It has significant implications for the dynamic regulation of flow rate, cross-layer stress and pressure transmission, as well as the coordinated control of inter-layer interference in the process of multi-layered combined production of coal measure gas.

Tight sandstone gas development is largely governed by mineral composition and micromechanical heterogeneity. This study proposes a cross-scale method integrating these two factors to characterize macroscopic sandstone heterogeneity. First, a CNN–Transformer model was trained on thin-section images to identify mineral types and contents. Second, probability density functions of Young’s modulus for each mineral were derived from nanoindentation data, and stochastic sampling was used to assign mechanical properties to mineral grains in an FDEM-GBM uniaxial compression model. Finally, numerical results validated against experiments show that the random spatial distribution of micromechanical parameters leads to a normal distribution of the macroscopic Young’s modulus. Decreasing high-strength mineral content reduces the mean Young’s modulus while increasing its standard deviation, indicating greater mechanical heterogeneity, with cracks preferentially propagating in low-strength minerals. Mineral composition and content are the primary controls on macroscopic behavior, while micromechanical heterogeneity plays a secondary role. A brittleness index integrating mineral composition and multi-scale Young’s modulus distribution is proposed, providing a theoretical basis for evaluating heterogeneity and fracability in tight sandstone reservoirs.

Accurately characterizing the three-dimensional multiphase microstructures of minerals is fundamental for achieving reliable mineral-scale rock mechanics simulations. However, acquiring high-fidelity three-dimensional mineral models typically requires destructive volumetric imaging that is costly and inapplicable to precious or inaccessible specimens. This paper presents a style-transfer-based framework for reconstructing 3D multimineral microstructures using only orthogonal surface images. This framework is capable of producing high-fidelity 3D mineral models at low computational costs without explicit statistical parameterization work. A discriminator-free 3D CNN generator supervised by a frozen pretrained VGG network through a Gram matrix-based texture loss is designed to synthesize 3D mineral models by encoding multiphase mineral statistics derived from 2D surface mineral maps. A novel high-frequency Gram loss implemented via Laplacian prefiltering supplements the conventional texture loss by selectively constraining the fine mineral boundaries that are critical for determining stress concentrations. The experimental results obtained for four-phase granite show that the developed framework generates realistic 3D mineral models whose morphological and spectral characteristics closely match those of a ground-truth serial grinding image dataset. Quantitative analysis confirms that the reconstructed 3D microstructures reproduce the original mineral volume fractions, grain size distributions, and spatial correlation functions. Material point method-based uniaxial compression simulations further yield macroscopic mechanical properties that are in strong agreement with both the experimental measurements and the ground-truth model. Cross-material demonstrations involving sandstone, a clay-pore structure, concrete, and a Martian rock specimen further confirm the potential generalizability of the framework.

The hard roof exhibits a considerable caving step,large block size,and high mine pressure,making it essential to investigate its damage and fracture characteristics for effective strata control.In this study,sandstone samples were carefully selected from the working face of Tashan Mine in the Datong mining area of Shanxi Province.These samples were deliberately prefabricated with cracks at various angles.A true triaxial cyclic loading and unloading test was then developed to simulate the actual mining conditions at the face of the mine.Subsequently,a numerical calculation tool based on the material point method and a strain softening constitutive model were used to establish a plane loading model incorporating different angles of prefabricated cracks.Comparison between the model calculations and experimental results revealed the capability of the model to accurately replicate the formation of real macroscopic physical cracks in fractured sandstone during cyclic loading and unloading,capturing the complex physical processes involved.Furthermore,a simulation study was conducted to examine the cyclic loading and unloading damage evolution process of fractured sandstone under varying angles of prefabricated cracks and different confining pressures.The findings indicate that:(1)The deflection angle of macroscopic crack propagation increases with the angle of the prefabricated crack.(2)Stress concentration areas in the sandstone samples originate from both ends of the crack during cyclic loading and unloading,extending to the rock's edge and diagonal in the stress concentration region.(3)As cyclic loading and unloading progress,dissipation energy steadily rises,especially with the development and propagation of macroscopic main cracks.Peak stress and dissipation energy at complete failure increase with higher confining pressures and angles of prefabricated cracks.These research finding can provide theoretical support for the control technology of hard roof in coal seams.

Accurate, cost-effective, and controllable reconstruction of three-dimensional (3D) digital samples of fractured rock masses is crucial for understanding the macro-mechanical effects of fractures. Traditional reconstruction methods are not only expensive but also limited by sample representativeness, often failing to capture the true complexity of fractures. In light of these limitations, this paper introduces an innovative method based on diffusion models, termed Text2Rock, for the reconstruction of 3D fractured rock mass digital samples with enhanced controllability. By incorporating a CLIP model and an improved U-Net3D network architecture, our approach enables control over key fracture characterization parameters such as fractal dimension, fracture intensity, and Feret's maximum diameter, thereby enhancing both the accuracy and controllability of the reconstructed samples. Reconstructed samples demonstrate that the proposed method can generate digital rock samples that closely adhere to the specified parameters, with reliability validated through two-point correlation coefficients and statistical analyses. Furthermore, the paper illustrates the application of these reconstructed samples in uniaxial compression numerical simulations, providing a new framework for investigating the macro-mechanical properties of fractured rock masses.

Understanding the capillary trapping mechanisms of hydrogen in natural rock with in-situ wettability is crucial for enhancing hydrogen recovery during underground hydrogen storage (UHS) in aquifers. In this study, microcomputed tomography images of the hydrogen-water-Bentheimer sandstone system acquired after drainage with hydrogen are utilized to calculate in-situ contact angles, reconstruct the pore model, and establish initial fluid distributions for subsequent simulations. A novel in-situ wettability modeling method for simulating pore-scale hydrogen-water two-phase flow is developed using the calculated in-situ contact angles and volume of fluid method. The effectiveness of this method is validated using experimental results. The hydrogen capillary trapping in Bentheimer sandstone under the in-situ wettability condition during both spontaneous and forced imbibition is simulated. The effects of water injection velocity and interfacial tension on hydrogen withdrawal are analyzed and discussed. The results show that (1) The hydrogen-water-sandstone system exhibits a heterogeneous water-wetting condition. Compared to experimental results, the developed in-situ wettability modeling method is more effective in predicting hydrogen-water two-phase flow in natural rock than previous methods. (2) The growth and accumulation of water films in the throats with large pore-throat ratios is the primary cause of snap-off events and capillary trapping of hydrogen. (3) The residual hydrogen saturation and hydrogen-water interfacial area decrease as the capillary number or water injection velocity increases. (4) The slight reduction in interfacial tension between gas and water due to the use of methane cushion gas has a negligible contribution to enhancing hydrogen recovery in the UHS.

In the face of intensifying global warming, carbon capture, utilization, and storage (CCUS) technologies are increasingly recognized as critical pathways toward achieving carbon neutrality. Although alkaline steel slag exhibits significant carbon sequestration potential, traditional mineralization methods are limited by low mass transfer efficiency and rapid efficiency decay caused by pore blockage and active surface coverage. To address these limitations, this study proposed an innovative approach leveraging steam-mediated activation to restructure the physicochemical properties of steel slag, thereby overcoming conventional barriers. Using a custom-designed hot steam-CO2 mineralization reactor, we systematically investigated the advantages of hot steam activation over conventional wet mineralization. Furthermore, we elucidated the effects of HS temperature on steel slag-CO2 mineralization efficiency and its underlying mechanisms. Results showed that the hydrated steel slag treated with hot steam exhibits a 2.4-fold increase in specific surface area and a 1.8-fold enhancement in porosity compared to conventional wet processing. This significant optimization of the mineralization conditions leads to an improvement in mineralization efficiency, reaching 22.48 %, which is four times higher than that achieved by conventional wet methods. With increasing hot steam temperature, mineralization efficiency showed significant enhancement, rising from 9.2 % at 100 °C to a peak of 35.14 % at 220 °C. The mineralization product CaCO3 exhibited a dual effect: filling micropores to reduce porosity for pores <3.5 nm, while forming new nanopores through stacking to increase porosity for pores >3.5 nm. The rapid generation of mesopores and macropores further drove the overall porosity increase. As HS temperature rose, the surface content of CaCO3 and C-S-H in MSS increased significantly. The pore-forming effect of CaCO3 stacking resulted in higher porosity, reaching 9.2 and 6.5 times the porosity and specific surface area of RSS at 220 °C, respectively.

Ground hydraulic fracturing has emerged as an effective technique for mitigating strong mining pressure manifestations in longwall top coal caving (LTCC). However, the influence of different hydraulic fracture types on the strength characteristics of hard roofs (HR) remains unclear, as does their impact on the fracture process and stress redistribution characteristics of HR. In this study, a numerical simulation tool based on the material point method (MPM) and a strain-softening model was employed to construct a model for LTCC involving overburdened multi-layer HR panels. Furthermore, LTCC mining simulation research was conducted, encompassing prefabricated horizontal hydraulic fracturing, vertical fracturing, and non-fracturing models. The results revealed the following: 1) The fundamental mechanism of HR fracture involves tensile failure induced by the gravity load of the overburdened rock layer when suspended. Vertical cracks resulting from surface hydraulic fracturing significantly diminished the tensile strength of HR, thereby greatly reducing its collapse step distance. 2) In LTCC, the stress transfer dynamics within rock layers were characterized by the following: horizontal stress concentrated in the middle through bending deformation of the rock layer upon suspension. Furthermore, upon reaching its peak, the rock layer fractured and collapsed, thereby releasing horizontal stress. Hydraulic fracturing-induced reduction in HR tensile strength effectively mitigated horizontal stress concentration. 3) Vertical stress concentration occurred through the collapse of lower rock layers and the pressure exerted by suspended upper rock layers. The appearance of its peak represents the collapse of multiple rock layers, and through hydraulic fracturing, the collapse step distance was effectively shortened, weakening the concentration of vertical stress.

The modeling of in-situ wettability is vital to accurately understand and predict two-phase flow in natural porous media. In this paper, the analysis of in-situ wettability in the pore-scale two-phase flow is implemented based on the automatic measurement of in-situ contact angle. The modeling method of the in-situ wettability in the porescale two-phase flow is developed by combining the measured in-situ contact angle and the volume of fluid method (VOF). The effect of heterogeneous wettability on pore-scale gas-water two-phase flow is also simulated and discussed. The results show that: (1) The in-situ contact angles of rock show a strong heterogeneity and present statistical Gaussian distribution. (2) Compared with the experimental result, the modeling method of insitu wettability proposed in this paper is more effective in predicting the pore-scale two-phase flow than that of the traditional method. (3) With the pore-scale displacement events such as Haines jumps and lateral and vertical-alternating growth of capillary fingers, the displacements under the heterogeneous weak water-wetting conditions with mean contact angles of 70 degrees and 80 degrees show the latest breakthrough times, as well as the highest breakthrough and final displacement efficiency.

To address the efficiency bottleneck caused by the passivation layer that envelops the active surface and obstructs the pores during the mineralization of CO2 in blast furnace slag (BFS), this study proposed a hot steam (HS) activation method. The study investigated the effect of different HS activation stages on BFS mineralization efficiency. The results reveal the following: (1) The HS pre-activation stage demonstrating the highest performance. Specifically, pre-activation at 180 degrees C for 20 min resulted in a mineralization efficiency of 29.6 %. Efficiency decreased sequentially from the HS pre- activation stage to full-process, later, and initial activation stages. (2) During pre-activation, mineralization efficiency increased with rising HS temperature up to 220 degrees C, peaking at 34.9 % at 220 degrees C. (3) Scanning electron microscopy indicated that the extent of surface coverage and accumulation of CaCO3 correlates directly with mineralization efficiency. In the HS pre-activation stage, HS facilitated BFS hydration, forming transition-zone macro-pores and gel pores. After mineralization, CaCO3 extensively covered BFS surfaces and filled its pores, increasing the carbon mass fraction from 0 % to 5.27 %. (4) The HS-activated mineralized blast furnace slag (MBFS) consistently exhibited enhanced porosity, with 22 % mineralization efficiency identified as a critical threshold. Below this threshold, pore-blocking effects from carbonate precipitation remain negligible, while beyond 22 % efficiency, the pore-filling effect of precipitated CaCO3 becomes increasingly pronounced, effectively moderating the rate of hydration-induced pore expansion. (5) With a pore size of 60 nm as the threshold, the porosity in the HS later activation stage first higher and then lower than that in the initial activation stage as pore size increased.

Ground fracturing technology is often used to treat hard roof in recent years. Current research on the mechanism of ground fracturing controlling hard roof mainly focuses on numerical simulation. However, the present numerical simulation methods reveal distinct limitations. Therefore, we developed a numerical model based on the material point method (MPM) to reveal the mechanism of ground fracturing. The model uses the convected particle domain interpolation (CPDI) technique to improve accuracy and a strain-softening model to describe the mechanical properties of rock mass. At first, the reliability of the model proposed in this study is verified by comparing the similar physical simulation test results of the same working face. Based on verification, hydraulic fractures are embedded in the 1# hard roof layer to simulate the impact of ground fracturing on the rock mass. Then the impact of hydraulic fractures on longwall mining is studied numerically. The results document that the hydraulic fractures are activated and communicated with the mining-induced fractures under the disturbance of excavation. This effect promotes the local slip caving of the hard roof, thereby reducing the advance abutment stress of the working face during the collapse of the hard roof.

The stability problems of layered rock mass are frequently encountered in tunnel and underground engineering. Affected by bedding plane, the mechanical properties of surrounding rock show obvious anisotropy, which makes its failure characteristics more complicated. Therefore, it is essential to clarify the deformation and damage characteristics of the tunnel in layered rock for the safe and efficient development. In this study, a numerical simulation tool based on material point method and strain softening model is used to establish the plane strain model of tunnel in layered rock, and the deformation process of the tunnel with different dip angles and different rock thickness is studied. The results show that: 1) Compared with the physical simulation test, it is proved that the tool used can simulate the complex process of tunnel deformation and instability, and effectively realize delamination, shear slip and rock fracture in the failure process of tunnel in layered rock; 2) The bedding plane has a significant influence on the failure characteristics of surrounding rock, and the damaged area increases significantly on the bedding plane, cracks are always concentrated in the direction perpendicular to the bedding plane, and the smaller the thickness of the rock layer, the larger the damage area of the surrounding rock; 3) With the increase of joint angle, the number of failure points presents a U-shaped trend, and the decrease of rock thickness will lead to an increase in the number of failure points and a decrease in the percentage of shear failure points.

We conducted continuous and transient impact tests using high-sensitivity pressure sensors to investigate the distribution of water jet impact pressure and its underlying mechanism. The following results were obtained: (1) Stagnation pressure decreases in the external flow field of the nozzle. At jet pressures of 1–7 MPa, peak pressure reached 64%–80%, and average pressure on the impact surface comprised 25%–37%. Higher jet pressures increased peak and average pressure attenuation rates as target distance increased. (2) Insufficient jet pressure contributed to excessive oscillatory energy consumption, resulting in pressure dispersion. Increasing jet pressure and adjusting target distance reduced oscillatory energy loss in the external flow field and decreased the dispersion of the pressure concentration area, improving jet energy utilization. (3) During transient impacts, an attenuation phase followed the water hammer pressure peak, with values approximately 1.4–1.8 times the peak stagnation pressure. High-speed imaging revealed that after receiving energy from the jet pressure, the water jet became more widely dispersed within the external flow field, forming larger areas of high-density compression. Increasing the target distance allowed the jet to attain a greater deflection distance at a given deflection angle, affecting both the impact area and its center.