Cavitation Region Research Articles

Numerical Prediction of Cavitation Erosion Risk Based on a New Erosion Indicator

ABSTRACTCavitation erosion would degrade the performance of the fluid machinery. To improve the reliability and prolong the life span of fluid machinery, it is necessary to study the mechanism of cavitation erosion and predict the possibility of erosion. Since the erosion power to be measured and calculated is closer to the actual state of cavitation, a new cavitation erosion indicator epp model based on erosion power is proposed, which can reflect the size and region of the erosion generated by cavitation more precisely. Concerning the cases of the axisymmetric nozzle and venturi tube, the prediction of cavitation erosion based on the newly proposed indicator is illustrated. It is found that cavitation erosion mainly occurs near the maximum margin of the cavitation region. This research indicates the possible erosion state of fluid machinery in a cavitation environment and provides a new approach to estimate the state of cavitation erosion.

Identification of incipient cavitation in control valve

Control valves as important elements in hydraulic systems are used to transport liquid and gaseous media, for example, water, water vapor, and hydrogen. They are mainly used in the power engineering, chemical industry, and so forth. Due to their large dimensions, the verification of hydraulic parameters is problematic. In the case of liquid flow, cavitation can occur, which is mainly characterized by noise, vibrations, or changes of hydraulic parameters. During the incipient cavitation in the valve, there are no noticeable changes in the hydraulic characteristics. The article, therefore, deals with the methodology of determining the cavitation by measuring and evaluating the characteristics of the valve, spectral analysis of noise, and vibrations during water flow. Mathematical modeling is also a suitable tool for determining the extent of cavitation in valve design. Newly created modified cavitation model, where the flowing medium is defined as a mixture of incompressible water and compressible gases (vapor and air), better corresponds to physical principles than the two-phase approach (water and vapor) with experimentally modified density and viscosity. Measured noise and vibration frequency characteristics and mathematically modeled pressure frequency characteristics identify cavitation in the (1 to 10) kHz range. The article proves that when identifying cavitation, the method of measuring hydraulic characteristics fails, but the method of measuring noise and vibrations is suitable in practice, i.e., in real industrial equipment, and the modified cavitation model is suitable for identifying cavitation regions in structural designs of the hydraulic elements.

Acoustic black hole immersed sonoreactor for high-efficiency cavitation treatment

Developing innovative sonoreactors to enhance acoustic processing efficiency holds immense importance in the field of sonochemistry. Traditional immersed sonoreactors (TISs) mainly produce cavitation at the probe tip, with a relatively weak cavitation around the probe, resulting in posing challenges for high-efficiency cavitation treatment. Here we propose an acoustic black hole immersed sonoreactor (ABHIS) in longitudinal-flexural coupled vibration, enabling high-efficiency cavitation treatment by unleashing the cavitation potential of the probe. The symmetrical structure of the probe is altered to introduce a coupling of flexural vibration mode, and an acoustic black hole (ABH) profile is integrated to further enhance both flexural wave number and amplitude. In this paper, we present a systematic theoretical design method for ABHIS and compare its performance with TIS using finite element method (FEM). An ABHIS prototype is fabricated and subjected to experimental tests and cavitation observation. The results demonstrate that our theoretical analysis model accurately predicts the frequency characteristics of ABHIS. The proposed ABHIS exhibits satisfactory dynamic characteristics, with significantly increased vibration displacement and acoustic radiation ability compared to TIS. Importantly, the ABH design significantly expands ultrasonic cavitation regions and enhances acoustic radiation intensity of ABHIS resulting in a substantial improvement in acoustic processing efficiency.

Performance characteristics of a contra-rotating pump-turbine in turbine and pump modes under cavitating flow conditions

Recent studies have indicated the potential of a contra-rotating pump-turbine (CRPT) as a low-head design that enables pumped hydro storage in regions with flat topography. However, the effects of cavitation have scarcely been investigated for the CRPT. The current paper utilises computational fluid dynamics simulations to study a model scale CRPT subjected to cavitating flow conditions to determine how cavitation affects the machine’s operating performance in both pump and turbine modes. In total, eight operating conditions have been evaluated for each mode. The inlet flow rate is considered fixed at 0.27 m3/s, while the outlet pressure is gradually changed to induce cavitating conditions. The study demonstrates that the pump mode operation of the CRPT is more sensitive to cavitation compared to the turbine mode. The pump mode operation shows a steady decline in efficiency with decreasing inlet pressure, whereas in turbine mode the efficiency settles at a lower level. The 3% head drop occurs at la Thoma number of 1.0 in pump mode and at 0.6 in turbine mode. At the 3% head drop, a large cavitating region is already present at the runner blades’ suction side of the runner closest to the lower reservoir in both modes. The large cavitating region causes the flow to separate from the runner blade surfaces, which explains the reduced operating performance. To ensure an almost cavitating-free operating condition and unaffected performance, the Thoma number needs to be above 1.0 in turbine mode and at least 1.5 in pump mode. A frequency analysis reveals that the presence of cavitation affects the dominant pressure pulsations in the system. A dynamic mode decomposition analysis is carried out, demonstrating that the non-trivial pressure pulsations are connected to the support struts.

A Method of Images to Study Plate-Impact-Induced Cavitation in Aluminum through Molecular Dynamics Simulation

The tensile stress generated by the superposition of two reflection waves in the target plays a critical role in explaining plate-impact-induced spalling. A method of images is proposed to simulate the physical process of wave superposition and this method is applied in order to study the cavitation mechanism in single-crystal Al through molecular dynamics simulation. The critical impact-load velocity for the cavitation obtained by this method is as small as 400 m/s, which is much lower than the result (650 m/s) obtained by the conventional piston-load method. The new cavitation mechanism found is distinctively different from the conventional dislocation-entanglement-induced cavitation under high-velocity impact. The new mechanism involves two key events: firstly, a crack-like defect is formed and its relevant atomic bonds are broken under high tensile stress, resulting in a great momentum of related atoms; and secondly, previous high-momentum atoms collide with the atoms in their running way, resulting in the destruction of the original FCC structure locally and nanovoids or penny-shaped voids being formed. Additionally, the cavitation region, the number of voids, and delamination surfaces increases with the impact-load rate.

Modeling and scaling of cavitation compliance in Venturi

Understanding cavitation compliance in Venturi is important for research on system oscillations in fluid machinery, which describes the responsiveness of the cavity size to alternating inflow parameters. To consider both Venturi geometries and inflow conditions in evaluating the cavitation compliance, the cavitation region is modeled as a large vapor bubble, based on the experimental characteristics of the attached cavity characterizing the cavity size. Steady-state numerical solutions of cavity sizes show the influencing trends by geometrical and inflow parameters consistent with experiments. According to the analytical solution approximating the numerical solution, effective cavitation number σe and effective length ratio L̃* are defined to unify these influencing parameters. Based on the causes of cavitation pressure drops at the throat indicated by σe, cavitation compliance can be categorized into two regimes. Regime I features a smaller σe, and the dynamic pressure dominates in the pressure drops, theoretically resulting in L̃*∝σe−9. Regime II features a larger σe, and the bend-flow inertia and dynamic pressure are comparable, resulting in L̃*∝σe−2 in contrast. The power-law predictions of cavitation compliance are validated by experiments and literature.

Slip velocity and field information of two-phase cavitating flows

In this work, laser-induced florescent particle image velocimetry was performed to measure simultaneously the liquid and vapor velocity fields at the mid-span of a small-scale Venturi type section to determine the presence of a slip velocity between the phases. Various dynamic behavior and Kelvin–Helmholtz (K-H) instability involved in the cloud cavity shedding regime are discussed at four different cavitation numbers. The velocity, vorticity, and turbulence field information of the two phases are analyzed. The liquid–vapor mixture in a cavitating flow is usually considered a homogeneous medium in currently used computational models, but it is shown in this study that the two phases have very different dynamics. The measurements of the time-averaged velocities highlight the existence of a noteworthy slippage between the liquid and the vapor phases, especially in the upstream part of the cavitation region, where the slippage between the two phases can reach about 50% of the liquid velocity. Using phase-locked average, it is shown that the slip velocity in the upstream region is mainly located at the upper liquid–vapor interface, while the slip velocity in the closure area is near the bottom wall, due to the reentrant jet. These results contradict a primary assumption of the current models, where the medium is usually considered as a homogeneous mixture with a unique velocity field, thus providing a reference for future computational model improvement.

Study on Cavitation Noise Monitoring and Characteristics Based on Venturi Bench Test

Cavitation phenomena are accompanied by harsh cavitation noise. Studying cavitation noise is an effective method to monitor cavitation conditions. In order to study the characteristics of cavitation noise, a Venturi test bench experiment platform is built, the cavitation flow field and cavitation noise of Venturi test bench are simulated. The frequency domain analysis of cavitation noise is carried out, and the relationship between cavitation region, flow rate and sound pressure level of cavitation noise is verified by comparison between simulation and experiment. Because the cavitation noise is easily polluted by ambient noise, wavelet transform is used to analyze the cavitation noise and background noise, and the characteristics of cavitation noise are studied by comparing the difference between them.

Influence of mass conservation cavitation boundary on transient performance of water-lubricated bearings

Given the current research gap regarding cavitation phenomena and startup conditions in water-lubricated bearings (WLBs), this study offers an innovative approach by integrating the mass conservation boundary condition proposed by Jakobsson, Floberg, and Olsson (known as the JFO boundary condition) with a transient mixed lubrication model of WLBs. It also considers the impact of elastic deformation and surface roughness peaks, thus establishing a transient startup model of WLBs that incorporates the cavitation effect. Furthermore, the dynamic behaviors of this boundary condition are contrasted with the commonly used Reynolds boundary condition during the startup process of the bearings, as well as under eccentric and step load impacts. The findings demonstrate that the JFO boundary condition, accounting for cavitation effects, significantly influences the transient performance of WLBs. The presence of a cavitation region diminishes the damping of the bearing system following step load impacts, leading to increased overshoot and adjustment time while weakening the system's self-adjusting ability against step loads. This study offers valuable insights for theoretical analysis of ship propulsion systems operating under complex conditions.

Eulerian–Lagrangian multiscale numerical analysis of multimodal partial shedding dynamics

The objective of this paper is to investigate the multimodal partial shedding dynamics from a multiscale perspective of cloud cavitating flows under two distinct cavity shedding mechanisms, namely the re-entrant jet mechanism and the shock wave propagation mechanism. A two-way Eulerian–Lagrangian coupling algorithm is applied to capture the multiscale vapor topologies from microbubble to large-scale cavities. The large-scale cavity evolution is solved through large eddy simulations (LES) with the volume of fraction (VOF) method in Eulerian frame. The sub-grid microbubbles are tracked in Lagrangian frame based on the discrete bubble model (DBM) method. The predictions agree well with experimental observation of the periodical cavity evolution and microbubble dynamics under both the re-entrant jet mechanism and shock wave mechanism around a NACA66 hydrofoil. The numerical simulation provides detailed analysis of the cavitating turbulent flow on the microbubble behavior with emphasis on the spatial-temporal distribution characteristics of microbubbles. The results show that the number and mean size of microbubbles in the cavitation region increase gradually with the growth of attached sheet cavity, development of re-entrant jet and collapse of largescale cavity for both cavitation patterns. Meanwhile, microbubbles are mainly distributed on the largescale interfaces where have high value of vorticity and turbulent kinetic energy under the effect of re-entrant jet and vortex structures. And the probability density functions (PDFs) of microbubble exhibit gamma distributions with a dominant peak at approximately 50 μm for both shedding mechanisms. However, the shock wave formation and propagation process only occurs in the final stage of cavitating flow under shock wave mechanism causing the condensation of vapor and the decrease of the number and mean size of microbubbles. Moreover, the microbubbles are uniformly distributed along the streamwise and vertical directions behind shock wave front.

Influence of starvation and cavitation on hybrid journal bearing under limited supply pressure

A new starvation model is established to explore the effect of starvation on cavitation and their couple influence on the performance of hybrid journal bearing. The starvation region is located in the recessed circumference and symmetry with the axial center. The novel starvation model aims to solve the issues of flow non-conservation by the axial starvation model and avoid calculation limitation by the JFO cavitation condition under severe starvation. The cavitation areas obtained by the approach, JFO model, and Reynolds model are compared to indicate the influence of starvation on cavitation. The static and dynamic performances are investigated by the three methods and the relative pressure distribution is given to analyze the effect of starvation and cavitation on the hybrid journal bearing. The result indicates that starvation has a significant impact on the cavitation region and has a slight effect on the bearing’s performance.

Impact of modelling assumptions in cavitating flow of simplified injector

Here, three-dimensional Reynolds-averaged Navier–Stokes (RANS) simulations are employed for in-nozzle flow modelling. The aim is to evaluate the capabilities and sensitivities of simulating in-nozzle flow phenomena by using homogeneous phase change models. Two commonly used homogeneous models are employed – (i) Homogeneous Equilibrium Model (HEM) and (ii) Homogeneous Relaxation Model (HRM) A simplified nozzle with reference experimental data is modelled in the developing, super cavitation, and hydraulic flip regimes using OpenFOAM. The influence of the inlet boundary condition and turbulence models are investigated. With HEM, three barotropic compressibility models are tested. The research seeks to understand the strengths and limitations of each approach by comparing different sub-models and their interactions with the flow fields and phase change phenomena. Ultimately, this study contributes to a better understanding of how different modelling choices can influence the accuracy and reliability of cavitation simulations using homogeneous phase change models. While the simulations demonstrated reliable predictions for low-order velocity statistics, substantial discrepancies were identified in the prediction of the cavitating region by both homogeneous models. Additionally, the relaxation model predicted only minor cavitation. In contrast, acceptable flow predictions were achieved using different barotropic compressibility models and inlet boundary condition types, as well as most RANS turbulence models, where the RNG k-ɛ model deviated more from the other turbulence models. Therefore, the added value of the present study is summarised as: (a) Four different cavitation regimes are simulated with HEM and HRM in a single study. (b) The more comprehensive HRM approach does not produce better velocity or cavitation predictions for a low-speed flow using the default relaxation time. (c) The choice of turbulence model can radically affect the cavitation prediction, in addition to velocity fields. (d) The HEM flow simulation has little sensitivity to the barotropic compressibility model.

Investigation of singlet oxygen and superoxide radical produced from vortex-based hydrodynamic cavitation: Mechanism and its relation to cavitation intensity

Presently, the hydroxyl radical oxidation mechanism is widely acknowledged for the degradation of organic pollutants based on hydrodynamic cavitation technology. The presence and production mechanism of other potential reactive oxygen species (ROS) in the cavitation systems are still unclear. In this paper, singlet oxygen (1O2) and superoxide radical (·O2−) were selected as the target ROS, and their generation rules and mechanism in vortex-based hydrodynamic cavitation (VBHC) were analyzed. Computational fluid dynamics (CFD) were used to simulate and analyze the intensity characteristics of VBHC, and the relationship between the generation of ROS and cavitation intensity was thoroughly revealed. The results show that the operating conditions of the device have a significant and complicated influence on the generation of 1O2 and ·O2−. When the inlet pressure reaches to 4.5 bar, it is more favorable for the generation of 1O2 and ·O2− comparing with those lower pressure. However, higher temperature (45 °C) and aeration rate (15 (L/min)/L) do not always have positive effect on the 1O2 and ·O2− productions, and their optimal parameters need to be analyzed in combination with the inlet pressure. Through quenching experiments, it is found that 1O2 is completely transformed from ·O2−, and ·O2− comes from the transformation of hydroxyl radicals and dissolved oxygen. Higher cavitation intensity is captured and shown more disperse in the vortex cavitation region, which is consistent with the larger production and stronger diffusion of 1O2 and ·O2−. This paper shed light to the generation mechanism of 1O2 and ·O2− in VBHC reactors and the relationship with cavitation intensity. The conclusion provides new ideas for the research of effective ROS in hydrodynamic cavitation process.

Research of Acoustic Cavitation: Results, Practical Implementation and Development Prospects

The most significant results of research performed in the Belarusian State University University of Informatics and Radioelectronics, aimed at creating methods and instruments for monitoring cavitation and controlling its activity, are presented. To achieve this goal, it was necessary to clarify the mechanisms and patterns of new and little-studied phenomena: ultrasonic capillary effect, sonoluminescence, cavitation noise and its spectral components and evaluate the possibilities of their use for hardware implementation as cavitation indicators. New cavitation phenomena have been discovered: reverse ultrasonic capillary effect, generation of constant EMF under the influence of alternating pressure of ultrasonic frequency; acoustic clearing of the cavitation area with pulsed modulation of the ultrasonic field, the effect of long-term memory of the cavitation properties of the liquid. Previously unknown patterns have been established: it is shown that the cavitation region goes through four stages of development with increasing ultrasound intensity; a theorem on the maximum cavitation activity was formulated; the spectral characteristics of cavitation noise were established, correlating with the intensity of sonoluminescence. It has been shown that pulsed modulation of the ultrasonic field makes it possible to control the dynamics of the development of the cavitation region and the activity of cavitation. Based on the data obtained, new methods and instruments have been developed to study cavitation and control its activity. In a number of parameters, the created equipment surpasses the best world samples, what is confirmed by deliveries to the Russia, EU countries, China, USA and South Korea.

Expansion of the cavitation region using ultrasound focus scanning in the direction of ultrasound propagation for an efficient method of histotripsy

Histotripsy is a non-invasive high-intensity focused ultrasound (HIFU) based therapy using the mechanical effect of cavitation bubbles. In this paper, we experimentally examined the effectiveness of a proposed method of scanning the HIFU focus in the direction of propagation to expand the region of the bubble cloud and increase the treatment throughput. First, the continuous generation of cavitation bubbles was observed with a high-speed camera, and it was confirmed that the region of bubble cloud generation could be expanded by focus scanning. Next, we performed ex vivo experiments. Tissue treated with histotripsy is disrupted and homogenized at the subcellular level, resulting in a decrease in the backscatter intensity of the ultrasound. Therefore, we observed the progression of tissue homogenization with histotripsy by evaluating the reduction of echo intensity in ultrasound imaging. The results suggest that focus scanning can improve the time efficiency of treatment.

Simulation study on the cavitation distribution in the ball valve of a common rail injector

A transient-state numerical simulation is conducted to investigate the cavitation flow in the ball valve of a common rail (CR) injector. The computational fluid dynamics (CFD) software, employing the RANS turbulence model, is employed for this purpose. The study aims to analyze the characteristics and underlying causes of the uneven distribution of cavitation in the ball valve. The results reveal a significant occurrence of cavitation, exhibiting an uneven distribution along the walls of both the ball and the valve seat. Notably, the initiation position of the intense cavitation region on the wall of the ball is observed to lag behind that on the wall of the valve seat. The intense cavitation region on the wall of the ball is found to reside behind the sealing surface of the ball valve. The intense cavitation region on the wall of the ball is located behind the sealing surface of the ball valve. This region experiences flow separation caused by main flow detour, resulting in the formation of vortices that entrapped the cavitation cloud, thus fostering the development of intense cavitation. Conversely, the intense cavitation region on the wall of the valve seat originates from the entrance of the ball valve. This can be attributed to the sudden change in geometry at the entrance, leading to a significant pressure drop and inducing cavitation based on geometric factors. Furthermore, the stagnation effect caused by the ball exacerbates the discrepancy in the distribution of the intense cavitation region between the ball and the valve seat.

ИССЛЕДОВАНИЕ КАВИТАЦИОННОГО ПРОЦЕССА В УЛЬТРАЗВУКОВОМ СМЕСИТЕЛЕ

An innovative way to solve pressing problems of energy saving and reducing environmental pollution during the operation of automotive equipment can be the use of a specially designed ultrasonic motor fuel mixer. The creation of cavitation areas in an ultrasonic mixer promotes the fragmentation of long hydrocarbon chains and thereby improves the quality of fuel (diesel and mixed diesel fuel), reduces fuel consumption, and prolongs the operation of the diesel engine fuel system. Possible modes of ultrasonic treatment were investigated in order to create an optimal cavitation region in the mixer. The establishment of treatment modes was carried out by changing the pressure-flow relationship in a laboratory installation, and the determination of cavitation areas based on the technique of numerical modeling of fuel flows in the structure under study. Numerical modeling made it possible to establish cavitation regions with different acoustic powers. The experimental studies of the hydrodynamic parameters of a real mixer indicate the adequacy of the developed model. 8 modes of ultrasonic exposure are defined depending on the pressure drop; they, in turn, are divided into pre-cavitation and cavitation. The operating pressure range was from 0 to 4 atm with a difference of 0.5 atm for each mode. The maximum reduction in kinematic viscosity (on average 23%) for all types of fuel is observed when the pressure drop reaches 2.5 atm. A further change in the cavitation regime towards an increase in the pressure drop does not lead to a significant change in the kinematic viscosity of motor fuels (about 2%).

Monitoring acoustic cavitation effects in tissues under the action of HIFU based on ultrasound images

The cavitation effect plays a key role in the field of High-intensity focused ultrasound treatment. By monitoring cavitation to adjust the irradiation dose, effective control of cavitation effects can be achieved, which is crucial for ensuring the safety and efficacy of HIFU therapy. In this paper, a method for monitoring cavitation effects in tissues based on ultrasound images is proposed. First, support vector machine is used to rapidly and accurately determine whether cavitation has occurred. Then, the improved watershed algorithm is employed to extract the regions where cavitation occurs, and the extracted cavitation region images are reconstructed using the total focusing method based on sparse array elements. Finally, to validate the feasibility and stability of the proposed method and investigate the development patterns of cavitation effects. An experimental system was established to conduct cavitation effect monitoring experiments on fresh bovine liver and a simulated human tissue model. The experimental results showed that, except for the recall rate in the fresh bovine liver test set, all classification metrics are greater than 0.9, demonstrating the practicality of the model established in this paper. The improved watershed algorithm achieved average values of Dice Similarity Coefficient, accuracy and precision at 93.69%, 96.74% and 92.23% respectively, representing a significant improvement compared to the traditional watershed method. The proposed total focusing method based on sparse array elements can effectively improve imaging efficiency while ensuring reconstruction accuracy.

Study on the Influence of a Rigid Wall on Cavitation in Underwater Explosions Near the Free Surface

A two-fluid, phase transition-based multiphase flow model is employed to simulate the dynamics of phase transition between liquid and vapor phases during shock wave and rarefaction wave propagation in underwater explosions. The aim is to understand the influence of a rigid wall on the cavitation evolution process and the cavitation collapse load, considering various charge quantities and water depths. The evolution of crucial physical qualities, such as the density, pressure, and the cavitation domain, within the flow field are analyzed and summarized. The presence of a rigid wall is found to significantly impact the cavitation evolution process in underwater explosions. It affects the shape, size, and dynamics of the cavitation domain, as well as the interaction between the explosion and the surrounding fluid. Specifically, the reflected wave on the wall influences the cavitation collapse load, leading to notable differences in the collapse time and collapse pressure compared to free-field conditions. Under different operating conditions, the size and position of the cavitation domain exhibit distinct changes. The proximity of the rigid wall results in unique patterns of cavitation domain evolution, which in turn lead to variations in the pressure distribution and the emergence of new cavitation regions. The findings of this study provide valuable insights into the behavior of cavitation and atomization induced by underwater explosions near the free surface. The understanding gained from these investigations can contribute to the development of effective safety measures and protective strategies in marine and underwater engineering applications. By accurately predicting and mitigating the effects of cavitation, it is possible to enhance the design and operation of underwater structures, ensuring their integrity and minimizing the potential risks associated with underwater explosions.

Numerical investigation of cavitation vortex dynamics in different cavitation patterns coupled implicit large eddy simulation and boundary data immersion method

The objective of this paper is to investigate the flow characteristics of different cavitation flow patterns around a NACA (National Advisory Committee for Aeronautics) 66 hydrofoil by applying the BDIM (boundary data immersion method) and ILES (implicit large eddy simulation) with an artificial code. Meanwhile, an artificial compressibility method is also employed to consider the effects of compressibility on cavitating flow. The results present that the numerical method can effectively capture different cavitation patterns, which agrees well with the previous experimental data. Subsequently, the detailed analysis of vortex structures and dynamics for the non-cavitation (σ = 3.0), sheet cavitation (σ = 2.0), and cloud cavitation (σ = 1.6) cases with the Liutex method and the vortex enstrophy transport equation have been investigated. When cavitation occurs, the degree of turbulence and the enstrophy in the flow field have been enhanced, due to the disturbance of the velocity field. For sheet cavitation, complex vortex structures appear in the attached cavity region with high-intensity enstrophy causing by the highly intense velocity and density gradient. As the cavitation pattern transits from the sheet cavitation to the cloud cavitation, more complex vortex structures can be observed in the cavitation region. Furthermore, the value and the fluctuation amplitude of enstrophy intensity increase significantly under the effect of reentrant jet. Analysis of the enstrophy transport equation indicates that the vortex stretching term and dilatation term for cloud cavitation increase relatively significantly with the movement of the reentrant flow and are highly dependent on the cavitation evolution. In addition, the region affected by the baroclinic torque also increases.