Increase In Pressure Ratio Research Articles

Three-dimensional discrete element analysis of the excavation face stability of deep-buried shield tunnels

To study the stability and the influencing factors of shield tunnel excavation face under deep burial conditions, relying on the Bailuyuan shield tunnel in the second phase of the "Water Diversion from the Han to the Wei River" project, we conducted indoor uniaxial compression tests, repose angle tests, and three-dimensional discrete element simulation analysis, calibrated the microparameters of the strata, and constructed a three-dimensional discrete element model of shield tunnel excavation face. The stability and settlement characteristics of the shield tunnel excavation face under different influencing factors were studied. Research results showed that (1) The horizontal displacement of tunnel excavation face and the critical chamber earth pressure ratio increase nonlinearly with the increase of tunnel burial depth; (2) The horizontal displacement of the excavation face, geological settlement, and critical chamber earth pressure ratio all increase with the increase of the cutterhead opening rate; (3) The horizontal displacement of the excavation face and the settlement of the strata increase with the increase of excavation speed and cutterhead rotation rate. The critical chamber earth pressure increases with the increase of cutterhead rotation rate, but is not significantly affected by changes in excavation speed; (4) As to the degree of influence, the burial depth has a significant impact on the horizontal displacement of the excavation face. The influence of the cutterhead opening rate and cutterhead rotation rate on the horizontal displacement of the excavation face is greater than on the settlement of the strata, while the influence of excavation speed on the settlement of the strata is greater than that of the horizontal displacement of the excavation face.

Effect of the change of foundation stiffness on the dynamic characteristics of base‐isolated structure

AbstractThe safety of an isolated structure built on the soft soil ground under the action of earthquakes is of major concern because the current seismic design of isolated structures has not considered the motions of the foundations caused by the effects of the soil‐isolated structure dynamic interaction (SISI). On this basis, a shaking‐table test method for base‐isolated structures on change of soil foundation stiffness was proposed and implemented. The foundation stiffness was controlled by the duration compression ratio and intensity of the input ground motion based on the influence of the increase in the excess pore water pressure ratio on the stiffness of the saturated sandy foundation. Meanwhile, the influence laws of foundation stiffness on the dynamic characteristics of base‐isolated structures were summarized and analyzed. The results showed that the first‐order natural frequency of base‐isolated structures on change of foundation stiffness decreased with an increase in the relative stiffness ratio of the structure–soil foundation (Rs), while its damping ratio increased significantly. The seismic isolation efficiency of the seismic isolation layer and the amplification effect on the rotational angular acceleration of the pile cap were significantly weakened. Meanwhile, under the same conditions, for the soil foundation with relatively small stiffness, the amplitudes of the bending moment and horizontal lateral displacement in the middle and upper parts of the pile remarkably increase because of the effects of the ISI. The research results of this test provide a certain scientific basis and reference for the seismic design of base‐isolated structures considering the SISI effects.

Predictors of VILI risk: driving pressure, 4DPRR and mechanical power ratio—an experimental study

BackgroundVentilator-induced lung injury (VILI) is one of the side effects of mechanical ventilation during ARDS; a prerequisite for averting it is the quantification of its risk factors associated with a given ventilatory setting. Many clinical variables have been proposed as predictors of VILI, of which driving pressure is the most widely used. In this study, we compared the performance of driving pressure, four times the driving pressure added to respiratory rate (4DPRR) and mechanical power ratio.ResultsIn a study population of 121 previously healthy pigs exposed to harmful ventilation, we compared the association of driving pressure, 4DPRR and mechanical power ratio to lung weight, lung wet-to-dry and total histological score. All the three variables were associated with these outcomes. Driving pressure, 4DPRR and mechanical power ratio increase linearly with the lung weight (adjusted R2 of 0.27, 0.36 and 0.40, respectively), the lung wet-to-dry ratio (adjusted R2 of 0.19, 0.25 and 0.37) and the total histological score (adjusted R2 of 0.26, 0.38 and 0.26). Using a multiple linear regression model with forward analysis, starting with tidal volume and progressively adding respiratory rate and positive end-expiratory pressure, and comparing the topic with the outcome variables, we obtained R2 values, respectively, of 0.07, 0.20, 0.42 for lung weight, 0.09, 0.19, 0.26 for lung wet-to-dry ratio and 0.07, 0.27, 0.43 for total histological score.ConclusionsDriving pressure, 4DPRR and mechanical power ratio, were all associated with lung injury in healthy animals undergoing mechanical ventilation.

CFD-based unsteady simulation and performance analysis of scroll compressor

The scroll compressor is an essential part of the heat pump air conditioning system in electric vehicles, with its performance and efficiency having a significant impact on the vehicle's range. This paper employs a combination of experimental and numerical simulations (using the dynamic mesh method) to study the scroll compressor in electric vehicles, exploring the effects of rotational speed and pressure ratio on compressor performance. The results reveal a significantly uneven temperature distribution across the chambers, primarily due to tangential leakage, which results in elevated temperatures in the central areas of the chambers and reduced temperatures near the meshing points. As the rotational speed increases, both the mass flow rate and the isentropic efficiency of the scroll compressor rise, whereas the discharge temperature declines; notably, discharge temperature drops by an average of 1.6 % for 600 r·min-1 increase in rotational speed. For each unit increase in the pressure ratio, the discharge temperature increases by an average of 12.22 K, while the mass flow rate decreases by 7.95 %. The study also shows that the isentropic efficiency initially rises with increasing pressure ratio, reaching a maximum of 67.06 % before starting to decline. These findings provide valuable insights into the performance characteristics of scroll compressors and offer theoretical support for optimizing compressor efficiency in practical applications.

Performance evaluation of supercritical CO2 Brayton cycle with two-stage compression and intercooling

Due to its small structures and high energy efficiency, the Brayton cycle using supercritical carbon dioxide (sCO2) can be implemented in various energy industries. The simulation model for a sCO2 recompression Brayton (RB) system with a two-stage compression and intercooling process (TCIP) is developed. At the design working conditions, there are minimum and optimum split ratios for the sCO2 RB with TCIP cycle. The sCO2 RB with TCIP cycle has a broader range of split ratios compared to the RB cycle. The sCO2 RB with TCIP cycle can achieve a minimum split ratio of 0.315, compared to 0.36 for the sCO2 RB cycle. The maximum efficiency of the sCO2 RB with TCIP cycle is 50.95 %, which surpasses the efficiency of the sCO2 RB cycle by 3.14 %. There exists an optimal value for the first-stage pressure ratio because the maximum efficiency of the sCO2 RB with the TCIP system tends to increase and then decrease with the increase in the first-stage pressure ratio. The pressure ratio of 1.1 for the first-stage compressor, corresponding to an interstage pressure of 8.25 MPa, maximizes the efficiency of the sCO2 RB with the TCIP cycle. The results can be used to further explore the applicability of sCO2 RB with TCIP.

Experimental study and sensitivity analysis of performance for a hydrogen diaphragm compressor

As the critical infrastructure of hydrogen in transportation, the energy consumption of hydrogen refuelling stations plays a pivotal role in the progress of hydrogen energy within the transportation sector. Volumetric and isentropic efficiencies serve as metrics for evaluating compressor performance. To investigate the extent of factors, including suction pressure, pressure ratio, overflow pressure, and rotational speed, to the efficiencies of the diaphragm compressor, an experimental rig was set up in this study. The volume and energy losses were analysed by studying pressure–volume diagrams. The result shows that elevating suction pressure results in an increased isentropic efficiency. Specifically, raising suction pressure from 0.2 MPa to 0.8 MPa yields a 10.2 % increase in isentropic efficiency. The increase in pressure ratio leads to a reduction in volumetric efficiency but an increase in isentropic efficiency. When the pressure ratio increased from 3 to 7, the volumetric efficiency decreased by 6.5 % in volumetric efficiency, but the isentropic efficiency increased by 9.8 %. Moreover, the escalation in rotational speed corresponds to a decrease in both volumetric and isentropic efficiencies. As the rotational speed increased from 420 r/min to 660 r/min, volumetric efficiency dropped by 9.6 %, and isentropic efficiency experienced a 19.2 % decrease.

Air Excess Coefficient and Irreversibility Value Analysis of Gas Turbines

Gas turbines used in natural gas cycle power plants have been researched in terms of energy efficiency. Gas turbines used in power generation plants have a very complex structure because they contain many components. In order to determine the thermodynamic performance of this system, the efficiency of each component and the increase in entropy of each component were calculated using exergy analysis. Irreversibility was chosen as the main parameter and used for thermodynamic optimization of production. The system consists of many components. An increase in the irreversibility of a single component causes an increase in the irreversibility of other components. The effect of gas turbine pressure ratio and excess air percentage on fuel consumption, fuel exergy, combustion chamber exergy change and irreversibility change was investigated. It was observed that the increase in compressor pressure ratio increased irreversibility. Maximum irreversibility was observed in the combustion chamber. Irreversibility was compared with the excess air used in the combustion chamber. The air excess coefficient was examined as percentages of 100%, 200%, and 300%, respectively. The compression pressure ratio was examined for air excess coefficient percentage values from 3 to 40.

Effect of tip injection on performance of highly loaded helium compressor in high-temperature gas-cooled reactor

As one of the representatives of the fourth-generation advanced nuclear reactor, the continuous development and application of high-temperature gas-cooled reactor (HTGR) technology has promoted the technical progress of the whole nuclear energy field. Helium compressor is one of the core components of HTGR. The highly loaded helium compressor effectively solves the disadvantages of the low single-stage pressure ratio and numerous stages of the traditional helium compressor. But it also brings a more complex tip-leakage flow. Tip injection, which is an active control method, can effectively control the tip clearance leakage and inhibit the development of the leakage vortex. This paper analyses the effects of axial deflection angle and injection pitch angle on the rotor performance of a highly loaded helium compressor via numerical simulation and validates them via experiment. Results show that the leakage vortex can be blown to the pressure surface of the adjacent blade by proper axial deflection angle to reduce the vorticity of the leakage vortex. The injection pitch angle directly affects the intensity of the leakage vortex during its initiation and development. When the axial deflection angle is 60° and the injection pitch angle is 20°, the adiabatic compression efficiency and total pressure ratio increase by 0.554 % and 0.160 % respectively under the design condition, and by 0.822 % and 0.162 % respectively under near-stall conditions.

Predictions of windage heating and flow characteristics in a high-speed rotating seal of aero-engine

The labyrinth seal plays a crucial role within the secondary air system of an aeroengine, significantly impacting its safety and reliability. This paper presents a comprehensive evaluation of the complex windage heating phenomenon within a high-speed rotating labyrinth seal system. Employing similarity criteria and dimensional analysis, the multifactorial influences on the seal system are thoroughly characterized. A dedicated high-speed rotating labyrinth seal test rig was constructed to conduct an experimental investigation into the windage heating characteristics of a four-tooth, stepped-slanted labyrinth seal. The results demonstrate a peak windage heating of 11.8 K and windage heating coefficient of 1.14 when the inlet temperature rose from ambient to 100 °C, under the rotating Mach number of 0.418 and pressure ratio of 1.1. Conversely, as the seal clearance increased from 0.2 mm to 0.6 mm, with a rotating Mach number of 0.487 and a pressure ratio of 2.0, the windage heating coefficient decreased to 0.57. Furthermore, five dimensionless operating cases were analyzed using similarity principles to elucidate the correlation between system performance and the combined effects of strong rotating flow and windage heating characteristics. The analysis revealed that the windage heating coefficient exhibited a decreasing trend with increasing flow Reynolds number, effective pressure ratio, inlet swirl ratio, and dimensionless clearance, as the effective pressure ratio increase from 1.1 to 5.0, with the rotating Mach number of 0.624 and flowing Reynolds number of 9600, the windage heating coefficient decrease from 1.831 to 0.797, representing a 56 % reduction. Conversely, the windage heating coefficient increased with a rising rotating Mach number, while the flowing Reynolds number demonstrated a minor influence.

Study on Rain Absorption Performance and Flow Field of Transonic Compressor under Different Working Conditions

Taking a four-stage transonic compressor as the research object, the Lagrange particle tracking method was used to simulate the multiphase flow by considering the particle fragmentation, collision and evaporation models, and the influence of different inlet conditions (raindrop diameter, velocity, temperature and flow rate) on the compressor’s performance and stable working range was studied. The results show that inlet rain absorption can weaken the clearance leakage vortex make the shock wave move downstream, thus increasing the inlet flow rate, resulting in a decrease in stability margin and the highest efficiency point moving in the direction of flow increase. With the decrease in raindrop diameter, the pressure ratio and wet compression efficiency increase, and the stability margin decreases. With the increase in inlet raindrop velocity, the degree of pneumatic breakage increases and the raindrop diameter becomes smaller, which leads to the decrease in pressure ratio and efficiency. The influence of the mass flow rate of imported raindrops on the stable working range is significant. When the mass flow rate of imported raindrops accounts for 5% of the design flow, the stable working range can be reduced by more than half. Rain absorption increases the reaction force of the compressor and increases the load of the rotor blade.

Analysis of cooperative cooling performance between the battery and cabin of pure electric vehicles

Abstract The cooperative cooling of the cabin and battery in pure electric vehicles (PEVs) is crucial for the comfort, thermal safety of the occupants, and the lifespan of the batteries. Therefore, a well-designed thermal management system (TMS) is particularly important. Thus, this paper constructs an cooperative cooling for the battery pack circuit and the cabin circuit in parallel, aiming to enhance the vehicle system’s integration and reduce energy consumption. Firstly, a one-dimensional simulation model of the cooperative TMS is established, and the model is calibrated through experiments. Subsequently, the system’s performance is analyzed under different ambient temperatures. The study finds that as the ambient temperature increases, the system’s energy consumption rises, and the Coefficient of Performance (COP) decreases. Moreover, when the system switches from the simultaneous cooling mode of the cabin and battery to the sole cooling mode of the cabin, the temperature of the cabin will fluctuate to a certain extent, within a range of 2°C. At same time, the COP value also increases with the switch of the mode. Finally, the analysis of the simultaneous cooling mode of the cabin and battery side under different ambient temperatures reveals that as the ambient temperature increases from 34°C to 42°C, the exhaust temperature, pressure ratio, and compressor speed increase accordingly, while the compressor efficiency decreases. The condenser and chiller experience a reduction in their heat transfer efficiency by 59.4 watts per degree Celsius and 218.5 watts per degree Celsius, respectively. Conversely, the evaporator’s heat transfer efficiency undergoes an enhancement of 6.77 watts per degree Celsius.

Drag reduction mechanism based on the aerospike-jet composite approach under different incoming dynamic pressures

The drag experienced by the nose of an aircraft varies significantly under different incoming flow conditions. In order to reduce the aerodynamic force on the nose of the (hypersonic) supersonic vehicle, the numerical simulation approach has been used to analyze the drag reduction laws and mechanisms of a blunt-body vehicle with the aerospike-counterflowing jet composite approach under different incoming flow dynamic pressures. The effects of two environments with H = 0.1 km and H = 30 km, as well as the influence of different incoming Mach numbers on the drag reduction at H = 0.1 km were investigated. The research has shown that there exists a minimum overall drag value for the vehicle under different dynamic pressures, while the variation in the wall pressure is related to the actual operating conditions. The recirculation zones at the aerospike and in front of the blunt body are important flow structures that affect the drag reduction. When the jet total pressure ratio increases, the position of the recirculation zone at the head of the drag reduction rod moves away from the central axis of the model. When the incoming flow dynamic pressure is higher, the separation point of the recirculation zone in front of the blunt body is located further downstream, and the reattachment point is related to the incoming flow and jet conditions, aligning with the trend of variation of the position of the maximum pressure on the blunt body wall. As it can effectively push away the shock wave, the enhanced drag reduction effect of the jet is significant when the incoming flow dynamic pressure is higher. However, the high jet pressure resulting from high dynamic pressure needs to be considered in the actual design. Furthermore, the complex turbulent flow field formed by the high dynamic pressure incoming flow and the jet is worthy of further study by means of the large eddy simulation.

Experimental Investigation and Numerical Validation of a Roots Pump’s Performance Operating with Gas-Liquid Mixtures

To facilitate the high operating pressure of a novel underwater power cycle, the potential of Roots pumps for pressurizing gas-liquid mixtures is experimentally investigated in this paper. The experimental facility is constructed, and the effects of inlet gas volume fractions and rotational speeds on the pump performance are discussed. The results show that the increased inlet gas volume fraction is beneficial to increasing the pump efficiency. This is associated with the increased pressure ratio and the gas-liquid mixture compressibility. In addition, the increases in rotational speed and liquid phase volume fraction negatively affect the pump’s efficiency. These phenomena are caused by the resulting high pressure difference and subsequently the back-flow from the pump outlet, thereby increasing the gap leakage and decreasing the Roots pump’s operating efficiency. The numerical model is further compared against experimental resultsk and the maximum difference is found to be less than 7.53%. This paper experimentally tests the potential of Roots pumps for pressurizing gas-liquid mixtures.

Effects of endwall clearances of variable diffuser vane on centrifugal compressor performance

To ensure the variable diffuser vane can rotate around a pivot fluently in practical applications, there have to be clearances between vanes and diffuser walls. As the compressor pressure ratio increases, the effects of the vane endwall clearances are enhanced and cannot be ignored. This paper investigates the effects of both-side vane endwall clearances on the centrifugal compressor performance. Results show that the existence of endwall clearances mainly enlarges the flow capacity of the vane diffuser and decreases the compressor efficiency, and these effects are more significant as the vane stagger angle decreases. A one-side endwall clearance of 2.7% of the diffuser width increases the choke mass flow rate by as much as 20% and decreases the compressor peak efficiency by 2.7%. Due to the non-uniform flow along span at the impeller outlet, the shroud-side vane endwall leakage plays a more important role than the hub-side in affecting the compressor performance. In additions, the respective contributions of the vane throat, the hub-side and the shroud-side endwall clearances to the increases of the vane choke mass flow rate are quantitatively studied. The flow physics and loss mechanisms of the endwall leakage are revealed.

Effect of self-excited oscillation of three-dimensional rectangular shock-induced thrust vector nozzle jet

The fluidic thrust vector nozzles including the shock-induced thrust vector nozzles stand out from traditional mechanical thrust vector nozzles used in aeronautics and astronautics due to their simplicity and potential for higher efficiency. However, a significant challenge in the transition from theoretical studies to practical applications is the phenomenon of self-excited oscillation of the nozzle jet, particularly in ramjet and scramjet engines. This oscillation can notably impact the jet control stability, which is critical for the operational reliability, accuracy, and safety of these engines. To investigate the effects of self-excited oscillation of the jet in the three-dimensional rectangular shock-induced thrust vector nozzles, a large eddy simulation approach has been utilized to examine various nozzle pressure ratios and secondary pressure ratios. The simulation data are in good agreement with the experimental data of National Aeronautics and Space Administration Langley Research Center, lending credibility to the simulation results. The research sheds light on the formation and evolution of self-excited oscillation. It does so by examining the interactions between shock waves and boundary layers, as well as bubble dynamics, offering a comprehensive view of the oscillation mechanism in a three-dimensional context. The results demonstrate that the self-excited oscillation of jet mainly belongs to low-frequency oscillation. With the increase in nozzle pressure ratio, the self-excited oscillation of the jet is suppressed because the shock system is pushed out of the shock-induced thrust vector nozzle exit. The variation of secondary pressure ratio only affects the amplitude of jet self-excited oscillation and does not transform the motion pattern.

Thermodynamic Optimization and Energy-Exergy Analyses of the Turboshaft Helicopter Engine

Energy demand is a critical contemporary concern, with significant implications for the future. While exploring renewable or sustainable energy sources offers potential solutions, optimizing energy consumption in existing power generation systems is also key. Aviation accounts for a substantial portion of energy demand, underscoring the importance of energy efficiency in this sector. Conventional energy analyses may be misleading; hence, employing exergy-based analyses provides a clearer understanding of energy consumption. Also, most of these analyses do not include the effect of the turbine blade’s cooling in calculations. In the present study, exergy analyses have been conducted on a helicopter turboshaft engine with turbine-blades cooling, focusing on design parameters such as ambient temperature, compressor pressure ratio, and turbine inlet temperature. Thermodynamic optimizations are conducted using a genetic algorithm. Results show that increasing pressure ratio and turbine inlet temperature boost performance, yet technical restrictions on compressor and turbine size, and metallurgical constraints on turbine blades’ material limit these gains. Sea level scenario prioritizes ambient temperature-drop for enhancing net-work and efficiency, while altitude-gain boosts turboshaft performance. Combustion chambers incur the highest exergy destruction of 74-80%, followed by 16-20% and 4-6% exergy destructions in the turbine and compressor, respectively. Lower air temperatures and higher flight altitudes demand larger fuel consumption for equivalent turbine inlet temperature, albeit enhancing cooling capacity and reducing required cooling air fraction for turbine blades.

Effects of Spatial Variation in Relative Density on Seismic Behavior of Saturated Sandy Ground

Proper consideration of variations in soil properties and their effects is necessary to enhance the seismic safety of structures. In this study, the effect of spatial variations in the cyclic resistance ratio on seismic ground behavior was investigated. Initially, dynamic centrifuge model tests were conducted on sandy ground featuring a 20% mixture of weak zones with low relative density and on homogeneous sandy ground with no mixture of weak zones. Subsequently, an effective stress analysis was performed by modeling the distribution of weak zones in the centrifuge model tests. Finally, after confirming the validity of the parameter settings, several analytical models with different weak-zone distributions were generated and numerically analyzed using random field theory. The results indicate that a local mixing of approximately 20% weak zones has only a limited effect on overall ground behavior. However, differences were observed in the rate of increase and dissipation of the excess pore water pressure ratio and in the residual horizontal displacement.

Study of the Effects of Different Ambient Gases and Buoyancy on Hydrogen Jet Characteristics.

Substituting nitrogen with inert gases in an inert gas cycle engine can not only effectively improve engine efficiency but also eliminate NOX emissions in the combustion products. Owing to the low density of hydrogen, jet development is affected by buoyancy. This study explored the effects of different ambient gases, such as Ar, N2, and He, as well as buoyancy, on the hydrogen jet and mixing characteristics based on Schlieren. The results indicated that as the pressure ratio increases, the penetration length and volume of the hydrogen jet increase, whereas the dispersion angle and entrainment ratio decrease. The penetration capacity of the hydrogen jet is strongest in He, followed by N2, and weakest in Ar. Additionally, in He, the hydrogen jet exhibits the smallest dispersion angle, fastest jet volume growth, and largest entrainment ratio. The entrainment ratio of the H2 jet in He is 2.75-3.84 times that of N2 and 4.72-8.3 times that of Ar. In N2 and Ar, the penetration length of the inverted jet after 2.5 ms is approximately 2-4 mm longer than that of the upright jet, indicating that buoyancy has a certain influence on jet development.

Upgrading the Compressor Stage of the CAT250TJ Micro Gas Turbine Engine

AbstractDue to their simplicity and relative ease of manufacture, single-stage centrifugal and mixed flow micro gas turbine (MGT) engines are preferred in thrust-based remotely piloted aerial vehicles. A single-stage mixed-flow compressor upgrade for the 200 N CAT250TJ MGT engine is numerically evaluated and presented. An in-house developed mean line application and commercial CFD software is used for the design and performance evaluation of the proposed upgrade configurations. The CAT250TJ – Gen1 engine features a single-stage centrifugal compressor, annular combustor, and single stage axial turbine. Apart from an upgraded impeller, a new crossover diffuser configuration is introduced to replace the wedge-type, straight outlet diffuser configuration of the Gen1 engine. The new single vane crossover diffuser configuration provides a design point total-to-total efficiency and pressure ratio increase of 8.3% and 12.1%, respectively. A disadvantage of a single-vaned crossover diffuser compared to legacy diffusers is a narrower operating range. To alleviate this issue, various combinations of tandem and splitter vane crossover diffuser configurations are proposed. These provide an enhanced operating range, comparable with the operating range displayed by the Gen1 configuration. A turbine power matching analysis is additionally completed to ensure proper compressor integration. Gas turbine cycle software is used to evaluate the on-engine performance of the upgraded compressor configurations. It is shown that the new baseline, single vane crossover diffuser configuration provides a 10.74% increase in design point static thrust.

Investigations of a turbine pre-swirl system with high temperature drop efficiency through the design of a novel vane-shaped receiver hole

The pre-swirl system, a vital system responsible for supplying cooling gas to the turbine blades. However, the pre-swirl system involves rotor-stator matching and intricate power-heat conversion challenges, which has led to a bottleneck in the development of its temperature drop potential. This study investigates the traditional pre-swirl system structure to identify factors limiting its temperature drop performance. A novel design idea is proposed to enhance the temperature drop performance by reducing the power consumption in the pre-swirl system. Subsequently, the structure optimization and performance improvement for pre-swirl system are conducted through the design of four vane-shaped receiver hole models. To assess the effectiveness of these enhancements, the thermodynamic and aerodynamic characteristics of the pre-swirl system before and after optimizations are evaluated using numerical simulations. Finally, the system temperature drop characteristics equipped with optimal receiver holes are thoroughly evaluated by experimental test analysis. The findings reveal that the new type of pre-swirl system, featuring a leading-edge vane-shaped receiver hole design and the removal of the cover-plate cavity, surpasses traditional designs. It exhibits a remarkable 35.3 % improvement in the receiver hole discharge coefficient, a 39.7 % reduction in system entropy increase, and a 6.36 kW/(kg/s) decrease in specific power consumption. Significantly, experimental verification demonstrates a 10 % increase in the nozzle pressure ratio, the temperature drop of pre-swirl system increased by 53.6 % from 23.5K to 36.1K, and the temperature drop efficiency of pre-swirl system increased from 0.567 to 0.872. Therefore, this study offers valuable insights for the design of high-performance pre-swirl systems, contributing to the overall improvement of turbine efficiency.