Leakage Flow Research Articles

Innovative foresight for water utilities asset management using PRISM software

Our analysis aims to better understand water losses by developing a specific methodology for estimating water leak flow rates and durations. Additionally, it aims to improve asset management practices for drinking water utilities by forecasting the costs and benefits of investment and operational decisions on the network. Current utility practices are compared to a "do nothing" policy and to the potential effective asset management policies proposed by an artificial neural network (ANN) based software, PRISM. Applied to four utilities in France, our methodology provides valuable insights for enhancing water loss estimates and finding trade-off asset management policies.

Numerical Investigation of Sediment Erosion in Guide Vanes of Francis Turbine with Experimental Validations

Abstract Serving as crucial elements within the distributor of Francis turbines, guide vanes aid in converting pressure energy into velocity energy. Additionally, they are responsible for directing water into the runner at the appropriate angle and quantity. The existence of a clearance gap in the guide vanes leads to the development of a leakage flow due to the pressure variation between the two sides. This leakage flow develops into a vortex, which interacts with sediment-laden flow and causes erosion of the guide vane as well as the runner. This study conducts a comprehensive analysis of erosion patterns in the guide vanes of a 2-kW model Francis turbine. Employing a dual approach that combines both experimental and computational methods, the investigation focuses on the impact of clearance gaps on erosion. The numerical study focuses on two cases, one incorporating a 2 mm clearance gap on the hub side of the guide vane and the other without the clearance gap. Both studies report erosion initiating from the mid-section and extending to the trailing edge at the suction side of the guide vane. Noteworthy is the leakage flow from the pressure side to the suction side of the blade, which, when converging with the main flow, disturbs the primary flow pattern and forms vortices, leading to erosion. This research also shows that the results from both the experimental and numerical analyses are in agreement.

Effect of the leakage flow through guide vanes on the erosion pattern and performance of Francis runner

Abstract The role of hydropower as a renewable energy source is well understood. However, due to the geological characteristics of certain regions, hydropower systems there are facing a unique challenge of excessive sedimentation in rivers. A significant number of research works were performed in the past, which focused on the effects of sediments on the turbine components, that includes reduction in efficiency of the turbine and increase in the erosion wear. Experimental studies of erosion in laboratory conditions are usually limited by several characteristics that affect erosion and complications of handling sediments. As a result, these investigations are normally carried out in a simplified apparatus. This study focuses on using a non-recirculating type of sediment erosion test rig, where a model of Francis turbine is used for experimental investigations. Previous studies have shown that in the case of Francis turbines, erosion occurs in the clearance gap of guide vanes, which increases the size of the gap. The flow from the pressure side of the guide vane is driven into the suction side due to the pressure difference between the two sides. This leakage flow ultimately develops into a vortex filament and hits the runner blades towards the hub and shroud. In this study, the erosion pattern of the runner blades towards these locations are studied by using color coatings. A clearance gap of 4 mm has been created in the guide vane and the consequent impact on the erosion and efficiency of the turbine are studied. The objective is to isolate the effects of leakage flow on erosion in the runner inlet, as well as the overall performance of the Francis turbine. The effect has been observed in terms of increased flow rate, decreased efficiency and erosion in the leading edge of the runner.

Fast flow field prediction of pollutant leakage diffusion based on deep learning.

Predicting pollutant leakage and diffusion processes is crucial for ensuring people's safety. While the deep learning method offers high simulation efficiency and superior generalization, there is currently a lack of research on predicting pollutant leakage and diffusion flow field using deep learning. Therefore, it is necessary to conduct further studies in this area. This paper introduces a two-level network method to model the flow characteristics of pollutant diffusion. The proposed method in this study demonstrates a significant enhancement in flow field prediction accuracy compared to traditional deep learning methods. Moreover, it improves computational efficiency by over 800 times compared to traditional computational fluid dynamics (CFD) methods. Unlike conventional CFD methods that require grid expansion to calculate all operation conditions, the deep learning method is not confined by grid limitations. While deep learning methods may not entirely replace CFD methods, they can serve as a valuable supplementary tool, expanding the versatility of CFD methods. The findings of this research establish a robust foundation for incorporating deep learning methods in addressing pollutant leakage and diffusion challenges.

Unsteady measurement in a transonic axial compressor with optimized axial slot casing treatment

Casing treatment has been widely adopted to enhance the operating range of compressors by extending the stall margin. In this article, a high-precision experimental investigation was conducted in a transonic compressor. Unsteady pressure is measured in the casing wall using a cluster of time-resolved transducers with axial and circumferential spatial resolution. The experimental data show that the optimized axial slot casing treatment improves the stall margin without peak efficiency penalty for all measured speedlines. A comprehensive flow field analysis indicates that the surge boundary of transonic compressor is sensitive to the position of shock wave and tip leakage flow. After the application of optimized axial slot casing treatment, the flow structure can be significantly modified, which specifically manifests as both the mitigation in shock wave detachment and redistribution of tip leakage flow trajectory toward the trailing edge of the blade. Furthermore, power spectral density analysis is conducted to examine the unsteady effect. The amplitude of characteristic frequency band induced by the unsteady fluctuation of tip leakage flow and shock wave is considerably suppressed, which can also be regard as the stability enhancement mechanism of casing treatment.

Experimental study of sediment erosion in Francis runner using a non-recirculating test rig

Abstract The problem of sediment erosion in hydraulic turbines has posed challenges in design, operation and maintenance of hydraulic machinery. A study was conducted with a 2 kW model Francis runner for investigating the erosion prone locations. The runner and guide vanes were coated with four different coats of colour (red, yellow, green, and blue). The system was then operated in sediment-laden condition with an average concentration of sediment particles of about 24000 ppm. The runner was operated in sediment-laden conditions for 36 hours and the observations were made after each 4 hours of operation. With increasing hours of operation, the colour coating of the runner was eroded at specific locations and a pattern was revealed showing the areas affected by erosion. The erosion was mostly observed at the trailing edge of the pressure side and the junction of the suction side of the blade and hub. Erosion on the hub was observed towards the leading edge of the runner in the area close to the suction side and the region near the trailing edge of blade. Similarly, the guide vanes were eroded at the pressure side of the leading edge and the trailing edge of the suction side. The causes of erosion were identified as high velocity and acceleration of sediment particles, inter-blade vortex, and vortex due to leakage flow.

Physics-informed neural network for turbulent flow reconstruction in composite porous-fluid systems

This study explores the implementation of physics-informed neural networks (PINNs) to analyze turbulent flow in composite porous-fluid systems. These systems are composed of a fluid-saturated porous medium and an adjacent fluid, where the flow properties are exchanged across the porous-fluid interface. The segregated PINN model employs a novel approach combining supervised learning and enforces fidelity to flow physics through penalization by the Reynolds-averaged Navier-Stokes (RANS) equations. Two cases were simulated for this purpose: solid block, i.e. porous media with zero porosity, and porous block with a defined porosity. The effect of providing internal training data on the accuracy of the PINN predictions for prominent flow features, including flow leakage, channeling effect and wake recirculation was investigated. Additionally, L2 norm error, which evaluates the prediction accuracy for flow variables was studied. Furthermore, PINN training time in both cases with internal training data was considered in this study. Results showed that the PINN model predictions with second-order internal training data achieved high accuracy for the prominent flow features compared to the RANS data, within a 20% L2 norm error of second-order statistics in the solid block case. In addition, for the porous block case, providing training data at the porous-fluid interface showed errors of 18.04% and 19.94% for second-order statistics, representing an increase in prediction accuracy by 7% compared to without interface training data. The study elucidates the impact of the internal training data distribution on the PINN training in complex turbulent flow dynamics, underscoring the necessity of turbulent second-order statistics variables in PINN training and an additional velocity gradient treatment to enhance PINN prediction.

Estimating and Reducing Leakages in the Water Distribution Networks of Small Settlements: The Case of Agios Germanos in the Prespes Municipality

Pressure management is a fundamental and highly effective method for the management of real losses in water distribution networks and therefore reducing non-revenue water. In this work, a methodology is developed to assess leakages in the water distribution networks of small settlements. The settlement of Agios Germanos in the Municipality of Prespes is selected as a representative case study. The hydraulic modeling of the water distribution network in the study area is used to assess the hydraulic behavior of the existing infrastructure in its current state of operation and to find critical locations to install the necessary measuring equipment (pressure sensors, flow meters, water level sensors, and pressure reducing valves). This equipment is used to calibrate the hydraulic model, estimate leakages, and manage them effectively. Minimum night flow analysis is utilized to assess leakages in the studied network based on measurements of the hydraulic parameters from the equipment installed. The effects of pressure management on leakages are then examined by assessing the relationship between the pressure and leak flow rate in the selected settlement.

Prediction of icicles on lining surface in high-speed railway tunnel in severe cold region based on the characteristics of daily temperature fluctuation

：Icicles in high-speed railway tunnels in cold regions pose a serious threat to operational safety. Tunnels with long lengths and large sizes require manual inspection, generating considerable work and expense for operation management. To reduce the workload of icicle inspection and guide manual deicing, a growth and development model of tunnel icicles was developed based on a tunnel icicle simulation system, and a tunnel lining icicle prediction and warning system was established, that provides guidance for deicing by predicting the range and development degree of tunnel icicles. The icicle simulation test shows that there is an obvious division of icing and non-icing area in the tunnel, and the boundary of the division is −5 °C. There is an optimum temperature range for the growth and development of icicle in tunnels. Under daily temperature fluctuations, the icicles grow back after being removed. A model for degree of icicle development was established. The degree of icicle development is affected by leakage flow, daily fluctuation amplitude of temperature, and daily average temperature. The smaller the daily temperature fluctuation and the closer the daily average temperature to the optimum temperature for icicle growth, the better the development of icicle. Based on the icicle development model, a prediction and warning method for icicles in tunnel was developed. Based on the network of instruments measuring and reporting temperature, the real-time temperature distribution of the tunnel was obtained, combined with the leakage distribution and volume in the tunnel, the icicles section and the icicles severity of the tunnel were obtained by analyzing the icicle growth model embedded in the system, providing guidance for the inspection of icicles in the tunnel. A comparison shows that the icicle prediction and warning system can reduce the walking inspection workloads by half.

Investigation of Reynolds number effects on flow stability of a transonic compressor using a dynamic mode decomposition method

With the continuous increase in aircraft flight altitude, low Reynolds number effects in high-altitude environments significantly impact the stability of compressor operation. In this study, dynamic mode decomposition (DMD) of the flow field at various time instances near stall conditions in a transonic compressor was performed to investigate the influence of Reynolds number (Re) effects on critical flow characteristics and instability mechanisms. The results indicate that under different Reynolds number index (RNI) conditions near stall conditions, the frequency of tip leakage flow varies. Under high RNI condition, the influence of tip leakage flow is concentrated mainly from the leading edge to the mid-chord. The stall mode is primarily caused by the interaction of shock with the Tip Leakage Vortex, resulting in the breakdown of the vortex. The development of vortex structures inside the passage leads to a delay in the flow field response to blade passing. Under low RNI condition, the tip clearance leakage flow is stronger, with a relatively reduced influence from the leading edge to the mid-chord and an increased impact from the mid-chord to the trailing edge. The main cause of the stall mode is the circumferential movement of vortex structures, causing secondary leakage over adjacent blade tip clearances. The blockage formed by vortex structures within the passage is weaker, and the flow field response to blade passing remains consistent with the blade passing frequency. However, as stall develops further, the flow field response significantly decreases.

Visualization and Quantification of Facemask Leakage Flows and Interpersonal Transmission with Varying Face Coverings

Although mask-wearing is now widespread, the knowledge of how to quantify or improve their performance remains surprisingly limited and is largely based on empirical evidence. The objective of this study was to visualize the expiratory airflows from facemasks and evaluate aerosol transmission between two persons. Different visualization methods were explored, including the Schlieren optical system, laser/LED-particle imaging system, thermal camera, and vapor–SarGel system. The leakage flows and escaped aerosols were quantified using a hotwire anemometer and a particle counter, respectively. The results show that mask-wearing reduces the exhaled flow velocity from 2~4 m/s (with no facemask) to around 0.1 m/s, thus decreasing droplet transmission speeds. Cloth, surgical, and KN95 masks showed varying leakage flows at the nose top, sides, and chin. The leakage rate also differed between inhalation and exhalation. The neck gaiter has low filtration efficiency and high leakage fractions, providing low protection efficiency. There was considerable deposition in the mouth–nose area, as well as the neck, chin, and jaw, which heightened the risk of self-inoculation through spontaneous face-touching. A face shield plus surgical mask greatly reduced droplets on the head, neck, and face, indicating that double face coverings can be highly effective when a single mask is insufficient. The vapor–SarGel system provided a practical approach to study interpersonal transmission under varying close contact scenarios or with different face coverings.

A Computational Analysis of Turbocharger Compressor Flow Field with a Focus on Impeller Stall

Understanding the flow instabilities encountered by the turbocharger compressor is an important step toward improving its overall design for performance and efficiency. While an experimental study using Particle Image Velocimetry was previously conducted to examine the flow field at the inlet of the turbocharger compressor, the present work complements that effort by analyzing the flow structures leading to stall instability within the same impeller. Experimentally validated three-dimensional computational fluid dynamics predictions are carried out at three discrete mass flow rates, including 77 g/s (stable, maximum flow condition), 57 g/s (near peak efficiency), and 30 g/s (with strong reverse flow from the impeller) at a fixed rotational speed of 80,000 rpm. Large stationary stall cells were observed deep within the impeller at 30 g/s, occupying a significant portion of the blade passage near the shroud between the suction surface of the main blades and the pressure surface of the splitter blades. These stall cells are mainly created when a substantial portion of the inlet core flow is unable to follow the impeller’s axial to radial bend against the adverse pressure gradient and becomes entrained by the reverse flow and the tip leakage flow, giving rise to a region of low-momentum fluid in its wake. This phenomenon was observed to a lesser extent at 57 g/s and was completely absent at 77 g/s. On the other hand, the inducer rotating stall was found to be most dominant at 57 g/s. The entrainment of the tip leakage flow by the core flow moving into the impeller, leading to the generation of an unstable, wavy shear layer at the inducer plane, was instrumental in the generation of rotating stall. The present analyses provide a detailed characterization of both stationary and rotating stall cells and demonstrate the physics behind their formation, as well as their effect on compressor efficiency. The study also characterizes the entropy generation within the impeller under different operating conditions. While at 77 g/s, the entropy generation is mostly concentrated near the shroud of the impeller with the core flow being almost isentropic, at 30 g/s, there is a significant increase in the area within the blade passage that shows elevated entropy production. The tip leakage flow, its interaction with the blades and the core forward flow, and the reverse flow within the impeller are found to be the major sources of irreversibilities.

Brush Seal Performance with Ideal Gas Working Fluid under Static Rotor Condition

The study investigated how variations in pressure ratio affect the leakage flow of a brush seal for both contact and clearance structures, in which the clearance is measured as the distance between the bristles tip and the rotor surface. This investigation utilized the Reynolds-Averaged-Navier–Stokes (RANS) equations alongside a two-dimensional axisymmetric anisotropic porous medium model. To verify the model’s accuracy and dependability, the obtained results were compared with previous numerical results and experimental observations, showing a satisfactory level of agreement. The results indicate that the predominant pressure drop occurs downstream of the bristle pack with the clearance model exhibiting a higher leakage rate compared to the contact model. Leakage increases proportionally with the pressure ratio, while axial velocity gradually rises and radial velocity experiences a significant increase. In conclusion, the leakage in the brush seal contact structure is significantly lower than in the clearance structure, resulting in the best performance.

Investigation of aerodynamic effects and dominant design variables of cavity squealer-tip in three-dimensional performance of a centrifugal compressor

Enhancing the performance of turbomachines has been a longstanding area of interest, with numerous geometry modification methods proposed in the literature. One such method, historically prevalent in turbines, is the cavity squealer tip. However, its application in compressors, particularly of the centrifugal type, remains relatively underdeveloped. This study employs the Taguchi method's L-9 orthogonal array as a sensitivity analysis (utilizing Design of Experiments) to investigate the impact of cavity squealer design variables on the performance of the NASA-CC3 compressor at three key operational points: choke, design, and near stall regions. Computational fluid dynamics is utilized to derive performance parameters, and various sets of design variables result in improvements across pressure ratio, isentropic efficiency, mass flow rate, and surge margin. Notably, a significant 20 percent enhancement in surge margin is achieved in one instance. The performance at the remaining operating points varies among the nine cases, with improvements observed in some areas and declines in others. Processing the data yields three optimal geometries, with the best configuration enhancing all performance parameters (0.59% for design mass flow rate and 2.20% for efficiency, maintaining a constant pressure ratio compared to the base). As anticipated, the optimal impellers exhibit reduced flow leakage compared to the baseline.

On-Site Characterization of Automotive Diffuser Aerodynamics by 3D LPT

This investigation proposes a novel LPT facility featuring Helium-Filled Soap Bubbles flow tracers, LED illumination and two high-speed cameras to characterize the dominating flow patterns within automotive underbodies. A remote control (RC) car model, fitted with custom-made floor and diffusers, traverses a region of seeded air following the Ring of Fire methodology. Underground-placed cameras view the car through a transparent panel, providing unparalleled optical access to the underbody of the car. The on-site measurement setup and the interaction between car model and ground enhance the realism and fidelity of the experiments, while potentially reducing testing costs associated with wind tunnel operation. The setup is shown to be a valid alternative to conventional testing approaches to capture flow separation, 3D flow evolution and differences in the flow field between the four tested configurations, whereby the diffuser angle was varied in the range between 5° and 20°. The 15° diffuser led to the largest velocity and pressure peaks under the car, whereas the 10° diffuser produced the most downforce thanks to the diffuser “pumping” effect, leading to a large region of low pressure under the vehicle. Notably, the 20° diffuser featured the most prominent flow separation at the diffuser’s leading edge, heavily affecting its ability to sustain low pressures under the car. The results show that the wide tyres have a major impact on the underbody flow, because their large wakes induce mass flow leakage through the sides of the car, thus disrupting the mechanism of downforce generation and impairing the generation of streamwise vortices.

Effect of tip clearance on non-synchronous propagating flow disturbances of compressor rotors under high aerodynamic loading conditions

The complex tip flow instability and its induced non-synchronous vibration have become significant challenges, especially as aerodynamic loading continues to increase. This study investigates the effects of tip clearance on non-synchronous propagating flow disturbances of compressor rotors under high aerodynamic loading conditions by conducting full-annulus unsteady numerical simulations with three typical tip clearance values for a 1-1/2 stage transonic compressor. The non-synchronous aerodynamic excitation frequency, circumferential mode characteristics, and annular unstable flow structures are analyzed under near stall conditions. The results show that the total pressure ratio and normalized mass flow parameters first increase and then decrease as the tip clearance increases from 0.5%C (where C represents the tip chord length) to 2%C under high aerodynamic loading conditions, instead of constantly decreasing. For the 0.5%C tip clearance case, the traveling large-scale tornado-like separation vortices cause a low non-synchronous aerodynamic excitation frequency and severe pressure fluctuations. The periodic shedding and reattachment processes of the rotor blades separated by 2 – 3 pitches result in 19 dominant mode orders in the circumferential direction. As the tip clearance increases from 1%C to 2%C, the difference of tip flow structures in each blade passage is significantly weakened, and the dominant mode order of the disturbance is equal to the rotor blade-passing number. The pressure fluctuation is mainly caused by cross-channel tip leakage flow, and the aerodynamic excitation frequency exhibits evident broadband hump characteristics, which has been reported as a rotating instability phenomenon.

UPDATED MATHEMATICAL MODEL OF THE TRUNK PIPELINE SECTION WITH LOOPING IN CASE OF LEAKAGE

Pipeline transport is the main method of moving volumes of oil and oil products, as it has several advantages, for example, quality safety and high throughput. At the same time, it also has some disadvantages, which can include the difficulty of increasing throughput without high capital investments and possible leaks and unauthorized tie-ins into pipelines, which are sometimes difficult to identify. Looping is one of the main ways to increase the throughput of the existing pipeline system, when the need to increase the volume of oil and oil products supplies requires the construction of several parallel pipelines — looping. At the same time, the basic mathematical model for calculating the section of the trunk oil pipeline with looping does not fully cover all the physical processes associated with the distribution of flows in the parallel section, which arise due to turbulences in the connection nodes, as well as head loss along the length of the jumpers. Taking into account the resulting flow redistributions, it becomes difficult to detect a potential leak, since any of the detection methods can not solve the problem with high accuracy with determining the leak coordinate with an unknown distribution of fluid flow rates in a parallel section. As part of the study, an updated mathematical model of the oil export pipeline section with looping was developed, which took into account the presence of a potential leak in the parallel section. Mathematical modeling was carried out on the basis of the assumption of a known coordinate, the effect of leakage on the redistribution of flows in a parallel section was estimated. To assess the impact of the leak, various coordinates and volumetric flow rates were set, based on the calculation results, graphs of the flow rate in looping versus its length and internal diameter were plotted. The study is the initial phase of developing a hydraulic location leak detection system for the oil export pipeline section with looping. The need to refine the mathematical model for determining the flow rate in the parallel section is an urgent and necessary task, the solution of which will allow identifying potential leaks with reliable accuracy.

Experimental study of flow control on tip leakage flow in variable geometry linear turbine cascades with different pivot layouts

Variable geometry turbines are essential for adjusting operational conditions in industrial gas turbines and variable cycle engines. These adjustments necessitate partial gaps at both ends of the variable guide vanes to alter the turning angle, consequently introducing an aerodynamic performance penalty. Moreover, the pivot layout profoundly influences aerodynamic losses. Research on turbine cascades that considers various partial gap layouts is limited, particularly in terms of experimental studies, which are rarely conducted. This study aims to diminish aerodynamic losses and augment the efficiency of gas turbines by examining the impact of pivot layouts on partial gap clearance and secondary flow. It further investigates the effectiveness of flow control strategies at the blade tip across different pivot configurations within a variable geometry turbine cascade, utilizing pneumatic probe scanning and surface oil flow visualization techniques. The results reveal that employing a cavity at the tip can significantly reduce aerodynamic losses in schemes both with and without a pivot, achieving maximum loss reductions of 15.8% and 3.7%, respectively. Additionally, a narrower squealer width can further decrease these losses. However, with a pivot located at the tip, the resulting separation flow and wake vortex become predominant sources of losses. The presence of the pivot weakens the tip leakage flow rate and the intensity of the tip leakage vortex (TLV), thus diminishing the effectiveness of cavity tip flow control. The cavity moderates TLV and enhances the interaction between TLV and the wake vortex, leading to increased aerodynamic losses.

A comparison of static and rotordynamic characteristics for two types of liquid annular seals with and without helical grooved stator

Less leakage is a benefit of parallel grooved liquid seals (labyrinth seals). But researches show that the liquid seal with parallel grooves on the rotor harms the rotor stability. The seal with helical grooves on stator performs well in terms of rotordynamics, and its leakage is sensitive to the rotating speed. To make use of the advantages of both seals and improve seal stability, based on the Smooth-stator/Parallel Grooved-rotor (SPG) liquid seal, a Helical Grooved-stator/Parallel Grooved-rotor (HGPG) liquid seal is designed. To evaluate two liquid seals’ leakage, rotordynamic characteristics and drag power loss, a transient computational fluid dynamics-based method is employed. This method is based on the multi-frequency elliptical-orbit rotor whirling model and the mesh deformation technique. The published experimental data of the leakage and rotordynamic force coefficients for an SPG liquid seal are used to validate the accuracy and dependability of the current method. Seal leakage and force coefficients are presented and compared for the SPG liquid seal and the HGPG liquid seal at various pressure drops. The influences of parallel groove depth on the leakage and rotordynamic properties for the HGPG liquid seals at two rotational speeds (2000, 6000 r/min) are analyzed. The numerical findings demonstrate that the novel HGPG liquid seal has a lower leakage flow rate (by ∼22.3%) than the traditional SPG liquid seal. There is an optimal parallel groove depth that minimizes leakage. The presented novel HGPG liquid seal significantly improves rotordynamic stability, due to the similar effective stiffness and the obviously larger positive effective damping. Reducing parallel groove depth can increase the positive effective damping. In terms of leakage and rotordynamic characteristics, the novel HGPG liquid seal is a better seal design for liquid turbomachinery.

Flow stability analysis on low-speed compressor with swept rotor blades under radial inlet distortions

Flow stability enhancement for axial flow compressors under radially distorted inlet conditions through rotor sweep design is an important issue for designers. To investigate the couped effect of rotor swept and radial inlet distortion on flow stability, steady numerical simulations, theoretical model predictions, and experimental validations were conducted for a low-speed, single-stage axial compressor (TA36) under various intensities of tip total pressure distorted inlet conditions with different swept rotor configurations. The steady pressure rise significantly decreases as the intensity of the distortion increases, whereas the rotor sweep has little effect on the pressure rise characteristic. The maximum error via model prediction is 1.25 %, while for steady numerical calculation, it is 3.89 %. Higher intensities of distortion lead to worse flow stability. Under radially distorted inlet conditions, forward sweep enhances flow stability whereas backward sweep further worsens it. What's more, quantitative analysis shows that the stability enhancement of forward sweep cannot fully counteract the adverse impact of radial distortion on flow stability. Elevated rotor tip loading was identified as the primary cause of instability under tip total pressure distorted inlet conditions. Forward sweep can slightly reduce this loading, whereas backward sweep has the opposite effect. Furthermore, the impact of rotor sweep on rotor tip loading intensifies with increasing distortion intensity. Unsteady flow field analysis was conducted. Which shows that radial distortion and blade sweep both affect flow stability by altering the intensity of tip leakage flow.