Experimental Rig Research Articles

A meta transfer learning-driven few-shot fault diagnosis method for combine harvester gearboxes

Combine harvester gearboxes operate for extended periods under variable operating conditions, making it costly to gather sufficient fault data. A meta transfer learning-driven fault diagnosis method for combine harvester gearboxes is proposed to solve the complex operating conditions and scarce fault samples. The meta learning is employed to train the model so that the performance of the proposed method is not contingent upon the quantity of training data. The multi-step loss optimization (MSL) method is introduced to improve the inner loop and address the unstable update gradients in training. The enhanced method uses each task to refine the model updating strategy, thus circumventing the gradient explosion and decay. The proposed method employs conditional domain adversarial network to extract deep discriminative features from both domains. The batch feature constraint (BFC) is proposed to balance the features’ transferability and class discriminability. A weight-balancing strategy is employed to reconstruct the training loss function, enabling gearbox fault diagnosis under variable operating conditions with few-shot data. The effectiveness of the proposed method is validated through data collected from the combined harvester gearbox’s fault diagnosis experimental rig.

Electromechanical modelling and vibration control analysis of cyclic symmetric structures with a piezoelectric vibration absorber

This study explored the application of piezoelectric vibration absorbers (PVAs) equipped with synthetic circuits for the vibration control of cyclic symmetric structures. A cyclic symmetric electromechanical model (CSEM) integrated with PVAs was introduced to facilitate the design and optimization of the PVAs. This model was formulated analytically based on the circulant matrix theory, and the dynamic response was computed using the complex mode superposition method with explicit consideration of the intrinsic resistance within the PVA. A case study involving a simplified blisk model and an experimental test rig was conducted to validate the proposed CSEM. The validity of the model was confirmed through a comparative analysis of both the natural and dynamic characteristics obtained using the finite element model and experimental results. Furthermore, the impact of synthetic circuit parameters (inductance and negative capacitance values) and the placement of piezoelectric patches on the vibration control performance of PVA were investigated. The results suggested that the optimal inductance coincide with the analytical value, whereas the optimal negative capacitance of the series was slightly greater than the intrinsic capacitance of the patch. Additionally, mounting the piezoelectric patch on the blade root improved the vibration control.

Comparative Analysis of Heat Exchanger Models for Phase Change Material Melting Process: Experimental and Numerical Investigation

ABSTRACTThermal energy storage systems using PCM offer promising solutions for efficient thermal applications. This study aims to provide valuable insights into the PCM melting process and compare the thermal performance of different heat exchanger models. The experimental rig is carefully designed to simulate a shell and tube heat exchanger with five longitudinal copper fins at specific conditions. Three distinct models of the heat exchanger, labeled Models A, B, and C, were examined for their heat transfer efficiency during the melting process. Numerical simulations were conducted for the three models and compared with experimental results. Model A represented the benchmark model. It had uniform fin length, location, and angle. Model B was the modified design aimed at enhancing melting progress. These modifications included a longer lower fin, a shorter side fin compared to the reference, and a lower fin angle to optimize heat transfer performance. Model C incorporates further design modifications, with a longer lower fin, a shorter top fin, and different lower fin location. Numerical simulations and experimental observations revealed significant differences in heat transfer performance among the three models. The average heat transfer rates, measured up to the critical decline point, are crucial parameters for practical applications. A comparison among the three models showed that Model B surpassed the average heat transfer rate up to the critical point of Models A and C by 10% and 4%, respectively, demonstrating its superior practical applicability.

An FBG-based method for load measurement of a cylindrical rolling element bearing

Abstract Contact forces between raceways and rolling elements of a bearing stand as crucial operational aspects defining the bearing’s performance. While monitoring bearing load through load cells or strain gauges on the shaft or housing is feasible, it may not precisely reflect the distributed load transmitted by the rollers directly to the raceways. This paper introduces a method to calculate these contact forces, relying on a linear assumption correlating the loads to the measured strains on the outer race of a bearing. In our research, we conducted both static and dynamic tests on cylindrical roller bearings through simulations and experiments. We designed an experimental test rig to conduct both static and dynamic experiments and utilized FBG optical fiber sensors for contact force measurement in bearings due to their multiple advantages, including high sensitivity, resistance to corrosion and magnetic interference, and ease of installation on the bearing outer race due to their shape and size. Our findings indicate a consistent linear relationship between contact forces and strains measured on the bearing’s outer race. Furthermore, we calculated the linear coefficient K values from three test groups: static tests under simulation study, static tests under experimental study, and dynamic tests under experimental study. The K values obtained from static tests (simulation and experimental studies) and dynamic tests (experimental study) align consistently. Following this, we calculated contact forces in both static and dynamic experiments by multiplying the measured strains with K. Our calculations resulted in an error percentage of less than 2% for static tests and below 5% for dynamic tests, highlighting the accuracy of our approach in determining these contact forces.

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.

Transient Analysis of Flow Unsteadiness And Machine Instabilities In a Centrifugal Compressor at Surge and Second Quadrant Operation

Abstract Instabilities in turbomachinery operation originate from intrinsic flow unsteadiness, sudden variations of operating conditions, and interactions with the surrounding system, affecting both system stability and machine reliability. The flow unsteadiness, presenting a characteristic behaviour, requires a deep understanding of the underlying flow fundamentals, a careful analysis using advanced experimental methods and a clear distinction on how the system might lead to instabilities. The identified approach addresses deep surge and second quadrant characterization. The analysis presented here benefits from the responsiveness and flexibility of the experimental test rig, fine tuning of the system layout, the instrumentation installation, and the transient tests procedure. The main focus area is the time-frequency analysis of flow and pressure signals at transients, thus providing a proper reconstruction of flow mechanisms and instability evolution. Valuable techniques include: short-time fast Fourier transform, wavelet analysis, and Wigner-Ville distribution; coherence between flow and pressure, to trace waves propagation, is considered too. These, presented outlining their strengths and weaknesses, are evaluated considering real time field applicability with regards to computational resources too. The experimental campaigns and data processing are presented, with a test matrix covering a wide range of parameters, including system layout and surge volume size, rotational speeds, flow rates ranging from nominal point to full second quadrant operation. These data are vital for system modeling validation for a full compressor-system digital twin. Results indicate the importance of ensuring reliable data acquisition and analysis, with adequate instrumentation range, accuracy, synchronization, responsiveness and positioning.

Impact of Nano-TiO2 Combination with Biodiesel on Diesel Engine Performance and Emissions Under Fuel Magnetism Conditioning

AbstractProblems of atomization, spray, and lower output power are due to the biodiesel’s higher viscosity. All of these aim to encourage fuel magnetism and nanoparticles addition to reduce fuel consumption. Waste cooking oil was converted to methyl ester by transesterification. To make methyl ester blend, diesel and biodiesel were mixed at volume ratio of 20%. TiO2 nanoparticles were added to biodiesel blend B20 at doses of 25 and 50 mg/L. TEM and XRD were used to characterize the nanomaterials. A magnetic coil was placed before the fuel injector to apply a magnetic field on the line of fuel. South pole of the magnetic field is located near to the fuel line, whereas the north pole is located further away. To examine the impact of these nanomaterials with fuel magnetism on engine performance and emissions using WCO biodiesel mixture, an experimental test rig was built connected to diesel engine. During testing, diesel engine operates at 1500 rpm with load variation. The average increases in BTE were 1, 1.5, 3.5, 5.5, and 6.5% but the decreases in BSFC were 1.2, 2, 4, 5, and 6% for B20 + magnet, B20 + 25 TiO2, B20 + 25 TiO2 + magnet, B20 + 50 TiO2, and B20 + 50 TiO2 + magnet, respectively, at engine load range. The average drops in CO, NOx, and HC concentrations were 16, 22, and 33%, respectively, at load range for B20 + 50 TiO2 + magnet. To improve engine performance and reduce emissions, biodiesel blend B20 from waste cooking oil with nanoTiO2 concentration of 50 ppm under magnetic field effect was recommended as a substitute fuel in diesel engine.

Aerodynamic Feasibility Investigation of the Novel Experimental Rig on Turbine Blade Tip With High Relative Motion

Abstract The relative casing motion can significantly alter the over-tip-leakage (OTL) flow aerodynamic performances. Traditional tip experimental facilities for relative motion researches, including stationary linear cascade with low-speed moving belt, annular cascade with rotating outer wall, and full-scale experimental rig with rotating blade, were either extremely costly or not capable to reproduce engine-representative casing Mach number. Very recently, a novel design concept for high-speed disk rotor rig has been proposed for tip research. Subsequent to this research, the present study evaluates the aerodynamic performances and the periodicity of the disk rotor rig design using Reynolds-averaged Navier–Stokes computational fluid dynamics simulation. Furthermore, first-of-its-kind experimental results of total pressure loss distributions measured by five-hole probe under high relative casing Mach number are reported. The results demonstrate the applicability of the disk rotor experimental rig for tip aerodynamic investigations.

Highly dynamic force control for experimental vibration analysis with an electrodynamic shaker

A new control method aims at the precise high dynamic control of the force signal for experimental vibration analysis, which is generated by an electrodynamic shaker. A bending beam is used as a nonlinear test object. A design and a surrogate model of the test rig are shown and parameterized based on test rig measurements. The force control algorithm using input/output linearisation is described and implemented in Matlab/Simulink for simulative validation studies. Conclusions drawn from the mathematical description of the problem as well as simulation results show that the design of the contact between shaker and test object is crucial to achieve a high control bandwidth and at the same time reduce the energy consumption of the shaker. This leads to the practical application using a novel damping contact element. Finally, experimental test rig results are presented which show a closed loop bandwidth of at least 250 Hz for sinusoidal excitation signals.

COOLING INJECTION EFFECT ON THE SUCTION SIDE NEAR-TIP REGION OF TURBINE BLADE WITH HIGH-SPEED RELATIVE CASING MOTION

Abstract The high-speed relative casing motion between the casing and the turbine blade tip introduces significant complexities to the flow field near the tip, resulting in alterations to the heat transfer distribution on the suction surface of the blade near the tip, and further influence the arrangement of film cooling arrangements. However, due to the challenges associated with measuring heat transfer, the influence of cooling injection on the near-tip region of the suction side under high-speed relative casing motion still remains uncertain. This study aims to address this knowledge gap by conducting experiments on a high-speed disk rotor experimental rig. The heat transfer coefficient and cooling effectiveness are investigated for different cooling hole arrangements. Additionally, based on Computational Fluid Dynamic (CFD) method, the interaction mechanism of cooling injections under high-speed relative casing movement is comprehensively discussed. It is observed that the cooling effect, which would be effective under stationary conditions, is greatly diminished or even rendered ineffective when subjected to high-speed relative casing conditions. Furthermore, arranging the cooling holes at the location where the interaction between the Over-Tip-Leakage flow and the passage flow occurs would be an effective approach to enhance the cooling performance on blade near-tip suction side. The effect of different relative casing speed on suction side near-tip region cooling injection performances are also numerically investigated. These findings contribute to a better understanding of the considerations involved in the film cooling design of turbine blades.

Development and tests of the novel configuration of the solar chimney with sensible heat storage

Heating, ventilation, and air conditioning systems account for a significant part of the energy usage in buildings and are primarily responsible for greenhouse gas emissions and operating costs. These can be lowered by the adoption of solar energy. This paper presents the developing and testing of a novel solar chimney with sensible heat storage. The thermal performance and potential contribution of the developed thermal chimney to decreasing residential buildings energy consumption in Polish climate conditions is investigated. The developed solar air chimney is composed of a novel accumulation material that allows for sensible heat storage. Solar radiation can heat the accumulation layer during the day and the stored energy can be used to preheat the ventilation air. The prototype of the solar chimney was tested in laboratory conditions using a dedicated experimental rig. Furthermore, numerical calculations were performed using TRNSYS software, where a validated dynamic numerical model was developed to simulate the performance of the device. The results show that airflow direction, volume, and the number of heated walls significantly impact the power transferred from the solar chimney walls to the air. The maximum power transferred from the solar chimney walls to the air per unit of surface varied from 360.2 W/m2 (when all walls were heated) to 672.4 W/m2 (when only one wall was heated). The validated model underestimates the outlet air temperature of the solar chimney by a maximum of 0.39 °C on average basis and shows that the increase of air temperature between −10 and 20 °C at 1000 W/m2 determines a decrease of 12.5 % of the thermal output. The obtained results allow one to highlight that the proposed solution can be considered as a replacement for typical brick chimneys located on roofs or as a thermal storage wall.

Ammonia Sprays for Combustion: A Review

Ammonia is a globally transported chemical used for a variety of applications, most notably, the production of fertiliser. Over the past decade, attention has been afforded to the use of ammonia as an energy carrier, coupling global supply of renewable energy to demand regions. Ammonia’s advantages as an energy carrier include its ease of liquefaction and established international transportation routes; overcoming its low reactivity, excessive production of nitrogen oxides and its toxicity remain as challenges. For energy applications, fuel delivery is a critical aspect of effective combustion in boilers, burners and engines. Due to its adaptable phase change characteristics, ammonia fuel may be injected as a liquid or vapour, each with respective advantages or disadvantages. The focus of this review concerns the characterisation of liquid ammonia fuel injection for combustion, including recent research findings from experimental and simulation studies. Liquid ammonia injection can result in the highly dynamic so-called ‘flashing’ or ‘flash boiling’ phenomena. Research findings have been drawn from other related applications such as accidental hazardous releases. Bespoke optical experimental rigs together with diagnostic techniques and two-phase computational fluid dynamics (CFD) simulations have enabled studies of the flashing jets under various initial or final conditions, with recent work also examining ammonia spray combustion. The review concludes with an insight into future trends and requirements for liquid ammonia combustion. Reciprocating engines for marine propulsion are cited as potential early adopters of ammonia energy.

Design selection of experimental test rig for static thrust on micro size propeller using Pugh method

This paper aims to propose a simple, straightforward, yet robust test rig design to measure the static thrust magnitude for small propellers. Although there were advanced tools like multi-axis force or torque sensors, sophisticated equipment and complex mechanisms were required to capture the accurate thrust magnitude. Therefore, providing simple and effective test rig design for small-sized propellers is quite challenging. In this work, Pugh matrix analysis was used to evaluate three new designs of Propeller Thrust Measurement Rig (PMTR) and compare the designs against a benchmark model. The evaluation covered important design criteria during test operation, such as measurement accuracy, stability, ease of development, assembly, maintenance, versatility, electronic integration, airflow interference, adaptability for tilt angle studies, and resemblance to multicopter flight conditions. The results reveal that the PMTR-1 design scored the highest in the analysis and emerged as the most suitable candidate among the proposed designs. It showed potential superior performance in stability, ease of development and assembly, versatility, simplicity, airflow management, and adaptability for future studies. PMTR-3 demonstrated some potential but needs more enhancement in electronic integration and structural development. However, PMTR-2 faces significant potential challenges in providing stability, versatility, electronic integration, and adaptability for effective and safe operations.

Performances of the ITER Pressure Suppression System during unstable steam condensation regimes

Abstract The paper deals with the qualification of the main safety system of the nuclear fusion reactor ITER: the Vacuum Vessel Pressure Suppression System (VVPSS). This safety system manages the Loss of Coolant Accident (LOCA), that could occur in the Vacuum Vessel (VV), avoiding a significant increase of the internal pressure that could breach the primary confinement barrier. Steam condensation occurs at sub-atmospheric pressure. This condition is original respect the usual applications of steam direct condensation in nuclear fission reactors. An extensive experimental research program, funded by ITER Organization, on reduced scale experimental rigs (scale 1/22 and 1/10) have been carried out at the University of Pisa. Unstable condensation regimes occurred during some tests at about 500 g/s of steam mass flow rate (10 % of the maximum steam mass flow rate foreseen for the relevant accidental scenarios). In these conditions, high intensity vibrations of the whole experimental rig occurred. These events can be classified as ‘Chugging’ or Condensation Induced Water Hammer (CIWH). 
The performed tests have been analysed elaborating the images of the video-cameras located in the pool and comparing the steam jet shape with the acceleration values recorded by an accelerometer mounted on the sparger structure.
These elaborations permitted to evaluate the dynamic of bubble collapse, the volume of the developed external bubbles, the collapse frequency as function of thermal-hydraulic parameters. 
Moreover, the paper emphasizes the beneficial effects of non-condensable gases on the unstable condensation regimes. In fact, the non-condensable gas inhibits the occurrences of Water Hammer inside the sparger and eliminates the thermal stratification inside the water pool increasing the turbulence.

Assessment of the Impact of Direct Water Cooling and Cleaning System Operating Scenarios on PV Panel Performance

Among the various renewable energy-based technologies, photovoltaic panels are characterized by a high rate of development and application worldwide. Many efforts have been made to study innovative materials to improve the performance of photovoltaic cells. However, the most commonly used crystalline panels also have significant potential to enhance their energy yield by providing cooling and cleaning solutions. This paper discusses the possibility of introducing a dedicated direct-water cooling and cleaning system. As assumed, detailed schedules of the operation of the developed direct water cooling and cleaning system should be fitted to actual weather conditions. In this context, different cooling strategies were proposed and tested, including different intervals of opening and closing water flow. All tests were conducted using a dedicated experimental rig. 70 Wp monocrystalline panels were tested under laboratory conditions and 160 Wp polycrystalline panels were tested under real conditions. The results showed that introducing a scenario with a 1-min cooling and a 5-min break allowed for proving the panel’s surface temperature lower than 40 °C. In comparison, the temperature of the uncooled panel under the same operating conditions was close to 60 °C. Consequently, an increase in power generation was observed. The maximum power increase was observed in July and amounted to 15.3%. On the other hand, considering selected weeks in May, July, and September, the average increase in power generation was 3.63%, 7.48%, and 2.51%, respectively. It was concluded that the division of photovoltaic installation allows reasonable operating conditions for photovoltaic panels with a lower amount of energy consumed to power water pumps.

Design of a test rig for the characterization of friction and wear in hot-metal gas-forming of AA 5083 aluminium sheets

Advanced aluminium sheet-forming processes such as the hot-metal gas-forming represent a challenging solution for producing small lots in the high-end car bodies industry, and the adoption of single cavity moulds made from low-cost, easily machinable materials such as cast iron reduces the overall sheet-forming costs. The tribological properties of the mould-sheet tribopair are of great interest for optimizing the sheet forming obtaining an acceptable esthetic surface finishing. This study presents the design and construction of a lab-scale experimental test rig for the tribological characterization at high temperatures of the mould-sheet tribopair. The proposed test method reproduces the sliding at the mould-sheet interface with contemporary sheet straining up to ε = 0.8 at strain rates in the 1.2*10-3 to 2*10-2 s-1 range. A series of experiments were carried out in dry and lubricated conditions for a ductile iron EN-GJS grade sliding against a AA 5083 aluminium alloy while straining. After comparing the experimental results with the literature data from other test rigs, comparable results were obtained as COF regards, ranging between 1.2 to 2.5 in dry sliding and between 0.05 to 0.2 in lubricated sliding. The morphological characterization of the sliding surfaces and cross-sections highlights the strong tendency to galling in dry sliding conditions expecially for low strain rates.

On the effect of wave amplitude and corrugation profile of certain types of corrugated channels on thermal performance and entropy generation

This study aims to examine experimentally and numerically the thermal-hydraulic performance and entropy generation of wavy channels: sinusoidal and triangular, and compare them with respect to the straight channel. Various wavy amplitudes and corrugation profiles are considered in a sinusoidal wavy channel and a triangular wavy channel and assessed with the straight channel. Experimental test rig is built and the experiments are carried out on laminar air flow and used to verify the simulation results. The main findings show that the HT rate, fluid flow, and entropy generation are affected by the corrugation profile and wave amplitude of the wavy channel. The maximum Nusselt number of 11.17 occurred in a sinusoidal wavy channel with a wave amplitude equal to 1.75, and high friction factor also happens in this model. It was found that the sinusoidal and triangular wavy channels with A = 0.75 and a flow rate range of 1–1.75 have the highest overall thermal performance factor. Also, the total entropy generation of the straight channel was lower than all corrugated channel models. In conclusion, it has been found that the best compromise between enhanced HT and the accompanying increase in both pressure drop and entropy generation is occurred in case of A = 0.75 at flow rate ranged from 1 to 1.67 LPM.

Characterization of Friction within a Novel 3 mm Wristed Robotic Instrument

Surgical robotic tools are being developed for a variety of surgical procedures that are executed within small workspaces. Novel designs of miniaturized cable-actuated surgical tools for cleft palate repair have previously been developed. However, the behavior and significance of friction within these tools are largely unknown. A study was conducted to investigate the friction in a pulleyless 3 mm diameter wristed instrument. The wrist utilizes cable guide channels that allow for miniaturization at the cost of increased friction. An experimental rig was developed to measure friction within the wrist link mechanism when the tool is positioned at various pitch angles. A strong relationship between the cable tension and the tool’s pitch angle was found as a result of friction. The cable tension increased as the pitch angle approached extreme values (percent increases in the cable tension of 33% and 67.3% at a pitch of 90° and −90°, respectively). However, the resultant cable tension was below the failure strength of the cable, indicating that the design is feasible. The results of this study would be useful to those considering the design of miniature robotic surgical tools that are cable-driven. Significant tool reduction can be achieved by employing static guide channels for the cables, forgoing the use of additional moving components like pulleys while maintaining cable tension well within its break strength. Future work in the design and optimization of novel miniaturized wrist mechanisms should consider frictional effects and their impact on mechanism function.

Flow Patterns of Tetraflouroethane Refrigerant in Different Small Diameter Tubes Used for Vaccine Delivery Boxes

This study aims to determine the flow patterns of tetrafluorethane refrigerant in different small diameter tubes. It attempts to establish a relationship among the temperature, pressure drop, volumetric flow of tetraflouroethane refrigerant in a 900 mm long small diameter tube. Tests are conducted to determine the effect of varying hydraulic tube diameter to the temperature and pressure drop of tetraflouroethane refrigerant in different flow rate. A copper tube with hydraulic diameter of 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm, 0.40 mm and 0.45 mm were used in this study. For every known hydraulic diameter, there are six (6) test points located in every 150 mm interval. The experimental rig is composed of six (6) pieces of 900 mm long copper tubes for the given hydraulic diameters. Each tube is marked with 150 mm, 300 mm, 450 mm, 600 mm, 750 mm and 900 mm. The markings represent the length of capillary tubes in millimeters where test points are located. A pressure transducer is attached to every test point and is used to measure the pressure drop at every length of the small diameter capillary tube. The result shows that pressure drop increases as the tube hydraulic diameter decreases and attained an evaporator temperature as low as -5 oC. The smaller the diameter of the tube, the more it is effective to give pressure drop for the design of a handy vaccine delivery box refrigeration system.

苜蓿切断-气吹茎叶分离方法初步研究

The protein content of alfalfa leaves surpasses that of stems significantly, rendering harvested alfalfa following stems-leaves separation a valuable resource for livestock feed, thus ensuring the provision of high-quality raw materials for production. This study introduces a novel process for stems-leaves separation, alongside the establishment of a suspension velocity experiment rig aimed at investigating and determining the suspension velocity of alfalfa leaves, stems, and plants across various moisture levels. The relationship among various factors including different alfalfa components, the length of lateral branches, stem lengths, Moisture Content (MC), and suspension velocity was empirically derived through experimentation. In this study, the chopping and blowing method was proposed, where the alfalfa was cut into pieces according to a certain length, and then the alfalfa was blown apart by generating airflow through a fan. To comprehensively analyze the impact of airflow velocity and cutting length on the Separation Evaluation Index, a response surface mathematical model was developed. The empirical findings indicate optimal stems and leaves separation of alfalfa when the airflow velocity reaches 4.29556 m/s, paired with a cutting length of 33.7956 mm. Conclusively, this experiment validates the efficacy of the chopping and blowing separation method for alfalfa stems and leaves segregation, thereby offering valuable insights into alfalfa stems and leaves separation practices. The outcomes of this study hold significant reference value for the broader alfalfa agricultural domain.