End Wall Research Articles

Multi-objective optimization analysis of air-cooled heat dissipation coupled with thermoelectric cooling of battery pack based on orthogonal design

As the energy supply core of electric vehicles (EVs), the battery's performance is closely related to its temperature. Therefore, the battery thermal management system (BTMS) plays a crucial role in ensuring the vehicle's driving safety and power performance. This paper proposes the air cooling as the primary heat dissipation method, combined with a semiconductor refrigeration sheet (SRS) to improve heat transfer and reduce local high temperature. Firstly, determine the optimum air volume with the U-type air-cooled structure. Additionally, orthogonal analysis is used to investigate the inlet and outlet locations, the front deflector position and length of the shunt chamber, and the rear deflector position on the air-cooling effect. Then, through multi-objective optimization, the optimal air-cooled structure is selected based on the air supply pressure drop. The chosen structure is the same-side dual-exit ventilation with a front deflector located 150 mm from the near-wind end wall and a length of 30 mm, and a rear deflector located 100 mm from the far-wind end wall. Finally, SRS coupled air cooling is used to dissipate the heat. Four SRSs are used to analyze the effect of mounting position and different currents on the battery pack. The findings suggest that the optimal placement for SRSs is parallel to the lower end of the battery module at the far-wind end. When SRSs pass a current of up to 0.4A at 37 ℃, the entire battery module can complete 7200 s discharge with 0.5C. This leads to a decrease in the maximum temperature (Tmax) to 46.09 ℃ and a drop in the temperature uniformity index (δT) to 1.36.

Effect of Tip Gap Size on the Tip Flow Structure and Turbulence Generation in a Low Reynolds Number Compressor Cascade

Abstract Efficient and compact axial compressors are currently undergoing rapid development for use in microcooling systems and small-scale vehicles. Limited experimental work concentrates on the inner flow field of the compressors working at such low Reynolds numbers (Re∼104). This study examines the vortical structures and the resulting turbulence production in the transitional flow over a C4 compressor blade at a Reynolds number Re of 24,000, with a specific focus on the impact of tip clearance. The particle image velocimetry measurements reveal the tip flow structures in detail, including the tip leakage vortex (TLV) and its induced complex vortical structures. The tip secondary flow at the low Reynolds number can be divided as the tip leakage flow (TLF)/vortex and transitional boundary layer both at the end walls and the blade surfaces. The TLV propagates at the highest spanwise positions and farthest pitchwise positions at the middle tip gap size (τ/C = 3%) for the three tip gap sizes investigated. The tip flow fluctuations decrease from τ/C = 5% to τ/C = 3% and then increase from τ/C = 3% to τ/C = 1%. The spatial distribution, streamwise evolution, and individual Reynolds normal stress components contributing to the turbulent kinetic energy (TKE) are discussed. The primary contributors to the turbulence generation are examined to elucidate the flow mechanism leading to the distinct anisotropic turbulence structure in the tip region with various tip gap sizes.

Tip-leakage-flow excited unsteadiness and associated control

Tip leakage flow in turbomachinery inherently generates intense unsteady features, named self-excited unsteadiness, which significantly affects the operating stability, aerodynamic efficiency, and noise but has not been well understood. A zonalized large eddy simulation is employed for a linear cascade, with wall-modeled large eddy simulation active only in the tip region. The simulation is well validated with advantages demonstrated for effectively reducing the computational cost while maintaining an equivalent prediction accuracy in the region of interest. The time-averaged and spatial-spectral characteristics of tip leakage vortex (TLV) structures are systematically discussed. The self-excited unsteady processes of TLV include the tip gap separation, the tip leakage and jet-mainstream interaction, the primary tip leakage vortex (PTLV) wandering motion, and the induced separation near end wall. The Spectral Proper Orthogonal Decomposition (SPOD) is used to examine the dominant frequencies and their coherent structures. It is found that these unsteady features change from a single high frequency to multiple lower frequencies due to the PTLV breakdown. The SPOD and correlation analyses reveal that the self-excited unsteadiness originates initially from unsteady vortex separation in the tip gap and is then fed by the interactions between the tip leakage jet and mainstream. The associated unsteady fluctuations are convected along the tip leakage jet trajectory, causing the wandering motion of PTLV core. Based on the revealed unsteadiness sources, a micro-offset tip design is proposed and shown to be an effective solution to reducing the tip flow unsteadiness. This work improves the understanding of tip-leakage-flow dynamics and informs the control of the associated unsteady fluid oscillation and noise.

Insights into shock velocity variation in double-diaphragm shock tubes

A comprehensive understanding of shock formation and propagation in shock tubes is crucial for their diverse applications. The shock velocity in single-diaphragm shock tubes, characterized by initial acceleration and subsequent attenuation due to viscous effects, has been extensively investigated. However, limited studies exist on the double-diaphragm mode of operation. In this study, shock tube experiments were conducted using helium at pressures of 10–60 bar as driver gas and argon at pressures of 100–600 Torr as driven gas. The shock velocity profiles in the double-diaphragm mode show a sequence of acceleration and deceleration stages of the shock front, strongly influenced by the driver-to-driven pressure ratios (P41) and the pressure in the intermediate section (Pmid). Particularly, at high values of P41, peak shock velocities can exceed those measured near the end wall by about 12%. Large axial temperature gradients arise in the driven gas due to the accelerating and decelerating shock. Selecting appropriate diaphragms to maintain the intermediate section's pressure close to the value of the driver pressure can reduce peak shock velocities and post-shock temperatures. An in-house one-dimensional (1D) weighted essentially non-oscillatory scheme-based code was utilized to analyze wave interactions in the shock formation region, revealing that the post-shock gas behind the secondary diaphragm and inhibition of the primary diaphragm's opening and subsequent reopening can lead to unique shock profiles in double-diaphragm shock tubes. These insights deepen our understanding of wave propagation in shock tubes and suggest ways to mitigate undesirable effects in double-diaphragm shock tubes.

Effect of the leading-edge vortex generator on the performance of the linear cascade

In this paper, based on the airflow improvement mechanism of dragonfly wing veins, a vortex generator is designed at the leading edge of the suction surface to improve the flow condition of compressor cascades. The influence of the placement positions and geometric dimensions of the vortex generators on the flow field structure and aerodynamic performance is investigated by numerical simulation. The research reveals that vortex generators at the leading edge of the suction surface can generate induced vortices near the end wall, suppressing the accumulation of low-energy fluid in the corner region. This results in a backward shift of the separation initiation point, a reduction in the corner separation region along the pitch direction, and a reduction in flow loss. The vortex generators exhibit favorable characteristics with positive incidence angles. However, when the incidence angle is below the minimum loss incidence angle, the vortex generators increase the flow losses of the cascade. Optimum performance is achieved when the vortex generators are positioned at the start of the corner separation. The flow control influence initially increases and then decreases as the height of the vortex generators increases. Similarly, the control impact is enhanced and then weakened as the placement position moves away from the suction surface. The flow losses decrease by 10.3% when the vortex generators are placed at the junction between the end wall recirculation and the mainstream region at a height equal to 2% of the blade height.

Mechanism for axial pattern formation of concentrated suspension in a horizontal rotating cylinder

We have performed numerical simulations to investigate the phenomenon of axial pattern formation exhibited by a non-neutrally buoyant concentrated suspension. Continuum modelling of the concentrated suspension is done using the suspension balance model to identify the underlying mechanism of the phenomenon. We demonstrate that axial concentration variations become amplified to axial bands owing to the influence of the second normal stress difference ( $N_2$ ), and the first normal difference ( $N_1$ ) accentuates the effect of $N_2$ . We demonstrate that the end walls of the rotating cylinder are necessary to prevent the smearing out of axial bands but are not a direct cause of the phenomenon.

Purge–Mainstream Interactions in a Turbine Stage With Rotor Endwall Contouring

Abstract Purge flows are prevalent in modern gas turbine design, allowing for increased turbine entry temperatures. The purge flow passes through a rim seal and interacts with the mainstream flow, modifying the blade secondary flow structures and reducing stage efficiency. These structures may be controlled using end wall contouring (EWC), though experimental demonstration of their benefit is seldom reported in the literature. The optically accessible turbine at the University of Bath was designed to directly measure and visualize the flow field within the blade passage for a rotor with EWC. The single-stage turbine enables phase-locked flow field measurements with volumetric particle image velocimetry (PIV). Purge flow was supplied to investigate a range of operating conditions in which the secondary flow structures were modified. The modular turbine rotor allowed for expedient change of a bladed ring, or bling, featuring non-axisymmetric EWC. The identified secondary flow structures were the pressure-side leg of the horse shoe vortex (PS-HSV) and an egress vortex (EV) of concurrent rotational direction. An increase in purge flowrate monotonically shifted the EV toward the suction-side (SS) of the adjacent blade. The migration of the PS-HSV toward the SS caused the two aforementioned vortices to merge. The EWC rotor design included a leading-edge (LE) feature to alter the PS-HSV and a trough to guide the EV low spanwise in the passage and maintain displacement from the adjacent suction-side. The EWC rotor was found to be effective at altering the formation and positioning of the secondary flow structures at a range of purge flow conditions.

Experimental and numerical research on blended blade and end wall technique in a compressor cascade

In this paper, to explore the effects and mechanisms of the blended blade and end wall (BBEW) technique on corner separation control, two different BBEW configurations, including the side blended blade and end wall (S-BBEW) and full blended blade and end wall (F-BBEW), are studied and compared through experimental and numerical analyses. First, for a linear cascade, the S-BBEW and F-BBEW designs are carefully built. Then, both numerical simulations and experiments are conducted for each design, demonstrating a significant reduction in the loss coefficient. The results indicate that the S-BBEW is effective in the control of boundary layer development and delays the initial point of separation, especially at the design working condition. Moreover, the F-BBEW design nearly eliminates the corner separation by the control of both boundary layer development and secondary flow, which provides a higher performance improvement, especially at a large incidence angle.

Investigation of control effects of end-wall self-adaptive jet on three-dimensional corner separation of a highly loaded compressor cascade

To overcome the limitations posed by three-dimensional corner separation, this paper proposes a novel flow control technology known as passive End-Wall (EW) self-adaptive jet. Two single EW slotted schemes (EWS1 and EWS2), alongside a combined (COM) scheme featuring double EW slots, were investigated. The results reveal that the EW slot, driven by pressure differentials between the pressure and suction sides, can generate an adaptive jet with escalating velocity as the operational load increases. This high-speed jet effectively re-excites the local low-energy fluid, thereby mitigating the corner separation. Notably, the EWS1 slot, positioned near the blade leading edge, exhibits relatively low jet velocities at negative incidence angles, causing jet separation and exacerbating the corner separation. Besides, the EWS2 slot is close to the blade trailing edge, resulting in massive low-energy fluid accumulating and separating before the slot outlet at positive incidence angles. In contrast, the COM scheme emerges as the most effective solution for comprehensive corner separation control. It can significantly reduce the total pressure loss and improve the static pressure coefficient for the ORI blade at 0°-4° incidence angles, while causing minimal negative impact on the aerodynamic performance at negative incidence angles. Therefore, the corner stall is delayed, and the available incidence angle range is broadened from −10°–−2° to −10°–4°.This holds substantial promise for advancing the aerodynamic performance, operational stability, and load capacity of future highly loaded compressors.

Determination of the Strength of a Container with Sandwich Panel Walls under Operational Loading Conditions

Purpose. The main purpose of this work is to present the results of determining the strength of a container with sandwich panel walls under the main operating modes of loading. Methodology. To ensure the strength of the bearing structure of the container, it is proposed to make its end and side walls from sandwich panels. This involves the creation of sandwich panels from two metal sheets, between which there is a filler in the form of an energy-absorbing material. The thickness of the sandwich panel sheets is determined by the Bubnov-Galerkin method. The sheet is considered as a thin-walled plate with the corresponding width and height parameters. To determine the strength of the load-bearing structure of a container with sandwich panel walls, the corresponding calculations were performed using the finite element method in the SolidWorks Simulation software package. The Mises criterion (IV theory of strength) was used as a calculation criterion. The spatial model of the container was created in SolidWorks. Findings. Taking into account the calculations, the rational thickness of the sheets, in terms of strength, of the side and end walls was established, which was 1.6 and about 3.0 mm, respectively. It is important that the use of rectangular corrugations makes it possible to reduce the thickness of the end wall sheet to 1.0 mm. The thickness of the side wall sheet is the same. The maximum stresses in the container in the case of its longitudinal loading occur in the fittings and amount to 268.3 MPa, which is 13.6 % lower than the permissible ones. The maximum stresses in the container under transverse loading were recorded in the areas of interaction between the side wall and the corner posts. The numerical value of these stresses was 178 MPa, which is 15.2 % lower than the permissible ones. Originality. The paper scientifically substantiates the use of sandwich panels as the walls of a uni-versal container. Practical value. The research will contribute to the creation of recommendations for the design of modern modular-type vehicle structures and improve the efficiency of the transport industry.

Modelling the impact of a dam‐break wave on a vertical wall

SummaryDam‐Break waves arise from the sudden release of the water stored behind a wall, and they cause destruction and losses on nearby areas. Characterisation of the impact force on obstacles is very important for risk assessment. In this work, we performed a series of lock‐release experiments to evaluate the wave‐induced impact force on a vertical end wall situated some distance from the lock. Laboratory data were used to evaluate the performance of several types of numerical models to predict the wave‐induced force on the vertical end wall. The selected models were as follows: the hydrostatic 1D De Saint‐Venant model, the multi‐layer hydrostatic model and the Navier–Stokes two‐phase flow. For the latter two models, both 2D (in the ‐ plane) and 3D simulations were performed. The results show that, independently of the hydrostatic assumption, the 2‐D simulations generate nonphysical oscillations which are not present in the measured temporal histories of the pressure and force values. By contrast, the predictions of both 3D numerical models better reproduce the temporal variation of the pressure forces on the end wall. The present study also shows that from a practical point of view, the 1D De Saint‐Venant model predicts with sufficient accuracy the impact time and the magnitude of the peak value of the impact force. Therefore, if the use of a fully 3D models is not a feasible option, in terms of a trade‐off between computation cost and accuracy, the use of a simple hydrostatic 1D De Saint‐Venant model is preferable to a 2D model.

Numerical simulation and experimental validation of the heat transfer characteristics in a circuit gas gap heat switch for the dilution refrigerator

The gas gap heat switch (GGHS) used for controlling heat transfer between different stages can be an important component for the precooling process of some dilution refrigerators. In this paper, a novel circuit GGHS is a rotationally symmetric heat switch assembly with annular fin arrangements to strengthen the heat-transferring effect. A numerical model considering 4He actual gas properties is proposed to investigate the heat transfer characteristics in the circuit GGHS, in which the effects of charge pressure, cold end temperature, thickness and length of walls on the mean thermal conductance (MTC) are studied. Simulation results show that the MTC increases with the growing cold end temperature, wall thickness, and length, respectively. Given the pressure of 10 kPa, cold end temperature of 4.2 K, wall thickness of 0.97 mm, and wall height of 66 mm, the theoretical MTC is 0.828 W/K. Experimental results indicate that the proposed simulation model is reasonable. Furthermore, the increment of the MTC decreases with the growing temperature. The GGHS used in experiments had a cold end temperature of 4 K, wall thickness of 0.65 mm, and wall height of 33 mm; the measured MTC was 0.219 W/K. Only when the temperature is above 10 K does the charge pressure have a pronounced effect on the MTC. This study provides helpful theoretical guidance for the design and optimization of the circuit GGHS.

A new rapid deflagration-to-detonation transition in a short smooth tube

A new rapid deflagration-to-detonation transition in a short smooth tube

Effects of curved vanes on aerodynamic performance and flow structures in highly loaded tandem cascades

Combining tandem cascades and curved vanes can mitigate the separation in highly loaded compressor cascades. Flow loss mechanisms in curved tandem cascades are crucial for fundamental design and optimization. This study investigates the flow losses and vortex structures in curved tandem cascades with different curved angles and an original straight tandem cascade. Numerical simulations are conducted at variable incidence angles. The results indicate no consistent effect of curved angles on the aerodynamic performance of curved tandem cascades. The tandem cascade with a curved angle of 5° effectively reduces losses at all incidence angles, while the tandem cascade with a curved angle of 15° extends the critical incidence angle to 3°. The comparative analyses reveal that curved vanes increase spanwise pressure gradients, causing low-energy fluid near endwalls to move toward the midspan. The weighting coefficient of losses quantitatively describes that curved vanes weaken the trailing edge shedding vortices of both vanes and passage vortex while enhancing the end wall spanwise vortex of the front vane, thus affecting the loss distribution. Finally, this study innovatively applies topological analysis methods to curved tandem cascades, establishing the relationship between topological structures and vortex structures in corner regions of tandem cascades, which provides a valid research approach to reveal the vortex dynamics mechanisms of the loss distribution in tandem cascades influenced by curved vanes.

Callose in leptoid cell walls of the moss Polytrichum and the evolution of callose synthase across bryophytes.

Leptoids, the food-conducting cells of polytrichaceous mosses, share key structural features with sieve elements in tracheophytes, including an elongated shape with oblique end walls containing modified plasmodesmata or pores. In tracheophytes, callose is instrumental in developing the pores in sieve elements that enable efficient photoassimilate transport. Aside from a few studies using aniline blue fluorescence that yielded confusing results, little is known about callose in moss leptoids. Callose location and abundance during the development of leptoid cell walls was investigated in the moss Polytrichum commune using aniline blue fluorescence and quantitative immunogold labeling (label density) in the transmission electron microscope. To evaluate changes during abiotic stress, callose abundance in leptoids of hydrated plants was compared to plants dried for 14 days under field conditions. A bioinformatic study to assess the evolution of callose within and across bryophytes was conducted using callose synthase (CalS) genes from 46 bryophytes (24 mosses, 15 liverworts, and 7 hornworts) and one representative each of five tracheophyte groups. Callose abundance increases around plasmodesmata from meristematic cells to end walls in mature leptoids. Controlled drying resulted in a significant increase in label density around plasmodesmata and pores over counts in hydrated plants. Phylogenetic analysis of the CalS protein family recovered main clades (A, B, and C). Different from tracheophytes, where the greatest diversity of homologs is found in clade A, the majority of gene duplication in bryophytes is in clade B. This work identifies callose as a crucial cell wall polymer around plasmodesmata from their inception to functioning in leptoids, and during water stress similar to sieve elements of tracheophytes. Among bryophytes, mosses exhibit the greatest number of multiple duplication events, while only two duplications are revealed in hornwort and none in liverworts. The absence in bryophytes of the CalS 7 gene that is essential for sieve pore development in angiosperms, reveals that a different gene is responsible for synthesizing the callose associated with leptoids in mosses.

Simulation of flow and debris migration in extreme ultraviolet source vessel

Practical extreme ultraviolet (EUV) sources yield the desired 13.5 nm radiation but also generate debris, significantly limiting the lifespan of the collector mirror in lithography. In this study, we explore the role of buffer gas in transporting debris particles within an EUV source vessel using direct numerical simulations. Our study involves a 2 × 1 × 1m3 rectangular cavity with an injecting jet flow subjected to sideward outlet. Debris particles are introduced into the cavity with specified initial velocities, simulating a spherical radiating pattern with particle diameters ranging from 0.1 to 1 μm. Varying the inflow velocity (from 1 to 50 m/s) of the buffer gas reveals a morphological transition in the flow field. At low inflow velocities, the flow remains steady, whereas higher inflow velocities induce the formation of clustered corner rolls. Upon reaching sufficiently high inflow velocities, the jet flow can penetrate the entire cavity, impacting the end wall. Interestingly, the resulting recirculation flow leads to the spontaneous formation of spiraling outflow. The distinct flow structures at various inflow velocities lead to distinct patterns of particle transport. For low-speed gas, it is efficient in expelling all particles smaller than 0.4 μm, while for high-speed gas, those fine particles accumulate near the end wall and are challenging to be extracted. Our findings highlight the significance of controlling flow conditions for effective debris particle transport and clearance in diverse applications especially in EUV source vessels.

A New Car-Body Structure Design for High-Speed EMUs Based on the Topology Optimization Method

In recent years, the research and development of high-speed trains has advanced rapidly. The main development trends of high-speed trains are higher speeds, lower energy consumption, higher safety, and better environmental protection. The realization of a lightweight high-speed car body is one of the key features in the development trend of high-speed trains. Firstly, the basic dimensions of the car body’s geometric model are determined according to the external dimensions of the body of a CRH EMU, and the specific topology optimization design domain is selected to establish the finite element analysis model; secondly, the strength and modal analyses of the topology optimization design domain are carried out to check the accuracy of the design domain and provide a comparative analysis for subsequent design. Then, the variables, constraints, and objective functions of the topology optimization design are determined to establish the mathematical model of topology optimization, and the design domain is calculated for topology optimization under single and multiple conditions, respectively. Finally, based on the topology optimization calculation results, truss-type reconstruction modeling is carried out for the car body’s side walls, roof, underframe, end walls, and other parts. Compared with the conventional EMU body structure, the weight of the reconstructed body structure is reduced by about 18%. The results of the finite element analysis of the reconstructed car-body structure prove the reliability and safety of the structure, indicating that the reconstructed car-body scheme meets the corresponding performance indicators.

Evaluation and Investigation of Hydraulic Performance Characteristics in an Axial Pump Based on CFD and Acoustic Analysis

In this work, the internal flow behaviour and characteristic pressure fluctuations of an axial pump with varying water conditions are analysed. The impact of tip vortex flow on the pattern of turbulent flow is simulated numerically by the application of the CFD technique and experimentally using an acoustics analysis method. The numerical CFD data are verified with an experimental test model for accuracy and reliability. Based on the results, the difference in pressure in the internal flow and at the surfaces of the blade can be impacted through tip leakage vortex regions, which leads to changes in internal flow. Subsequently, the flow in the clearance and tip leakage vortex regions is changed. Moreover, the results reveal that the suction wall upstream is more unsteady near the surface due to more mixing, secondary flow, and tip leakage vortices. Pressure fluctuation occurs near the tip of the blade, caused by the increasing vortex flow velocity and hence raising the turbulent kinetic energy (TKE). Using different monitoring points at the blade impeller reveals high values of the pulsation amplitude. Owing to the region of clearance backflow under low-water conditions, the axial pump displays larger fluctuations in pressure near the tip blade area. Because the leakage flow leaves the gap at a high flow rate, shear layers are formed quickly between the main flow and the leakage flow. Near the end wall, there is a negative-vorticity-induced vortex. Moreover, as the flow rate increases, the pump’s amplitude decreases along with its main frequency. For the low-water flow, the results reveal that there is an important clearance backflow because the axial pump has large clearance.

Flow mechanism of a highly loaded low pressure turbine cascade with integrated-optimized end wall contouring and root lean

The end wall loss of modern highly loaded low pressure turbine (LPT) has been greatly increased, due to the enhanced secondary flow loss and boundary layer separation loss. Thus, it is of great significance to develop effective flow control strategies to improve the end wall flow condition and aerodynamic performance of modern LPT. This research carried out a numerical investigation on the coupled flow control strategy, which combined non-axisymmetric end wall contouring (NEC) and root tangential lean (RTL), based on a highly loaded LPT cascade (Zweifel = 1.59). Meanwhile, the optimization process was used to get the optimal design parameters of the coupled method NEC&RTL. The results indicate that the optimal coupled configuration can reduce the total pressure loss coefficient by 12.68% and the non-dimensional secondary kinetic energy by 23.91%. Compared with the reference cascade without modification, the coupled method is found to improve the end wall flow conditions: the passage vortex is weakened both in size and strength, mainly attributed to the smaller cross-passage pressure gradient resulting from NEC; the closed separation bubble near end wall and the three-dimensional separation flow before trailing edge are eliminated, due to the great downward pressure gradient near end wall resulting from RTL; and the counter vortex is eliminated and the slender back flow is weakened under the additional coupling flow control effect of NEC&RTL. Therefore, the coupled flow control method can not only highlight the advantages of the independent methods, but also induce external flow control superiorities, demonstrating the application prospect of the coupled flow control strategy on the highly loaded LPT.

Controlling the flow loss of a supersonic compressor rotor using the blade slotting method

The flow loss in the blade passage of a supersonic compressor rotor mainly comes from the boundary layers on the blade surface and end wall, the shock wave, the shock wave/boundary layer interaction, and tip leakage flow; the instability is mainly caused by the shock wave near the rotor blade tip exiting the blade passage. This paper adopts an internal slot in the blade, with the inlet of the slot located at the leading edge of the blade and the outlet located on the suction surface of the blade, by using the momentum of the incoming flow to form a high-velocity jet to control the flow loss and improve the stall margin of the supersonic rotor. The mechanism of reducing flow loss by a slotting jet was studied, and a genetic algorithm optimization platform was further used for the coupled optimization design of the slot and blade. The numerical calculation results showed that the slotting jet can effectively suppress the development of the boundary layer on the suction surface while reducing the intensity of the shock wave, thereby reducing the loss of the boundary layer and shock wave, significantly improving the peak efficiency of the rotor, and increasing the mass flow rate at the peak efficiency point. The slotting jet can cause the shock wave in the passage to move downstream, thereby improving the stall margin of the rotor. Due to the strong shock wave in the blade passage near the blade tip, the slot outlet should be near and upstream of the shock wave; the shock wave in the middle and root regions of the blade is weaker, and the slot outlet should be located downstream of the shock wave.