Internal Vortex Research Articles

Research on the Comparison of the Flow Evolution Mechanisms of a Water-Jet Pump Between Valley and Peak Conditions

The pump hump significantly influences the vibration and operational stability of pumps. During the development of the mixed-flow waterjet pump, our team found that the pump performance curve had a hump phenomenon and the platform had vibration, so it was suspected that there was a strong secondary flow in the hump region. The calculation model is the SST k-ω turbulence model. The impeller and diffuser use structured grids. By using high-speed photography technology, we map the cavitation flow structures, thereby demonstrating the evolution of cavitation processes. The hump curve was obtained by an experimental test. By comparing the test data and numerical simulation, the consistency of the method and the hump curve is verified. A comparative analysis is performed to investigate the variations in the distribution of internal vortex structures and the evolution of rotating stalls in the impeller. In the valley condition, the main frequency of pressure pulsation in the inlet section of the impeller is 0.75 times the shaft frequency, the main frequency in the middle and outlet sections of the impeller is 1 times the shaft frequency, and the main frequency in the diffuser basin is 1.5 times the shaft frequency, the main frequency in the peak condition at the points of Span = 0.1 and Span = 0.5 of the impeller is the diffuser frequency, the main frequency at the point of Span = 0.9 is the impeller blade frequency, and the main frequency in the diffuser basin is either the shaft frequency or the diffuser blade frequency. This research reveals the characteristics of vortex flow in the pump under hump conditions. It reveals that the evolution mechanism of the hump offers a guide value for the subsequent hydrodynamic design of the hump.

Working Condition Sensitivity Analysis and Optimal Structure Parameter Determination of IVT Based on CFD and Orthogonal Experiment

To address liquid accumulation in horizontal gas wells, a specialized internal vortex tool (IVT) was developed for use in the horizontal sections, functioning as a drainage gas recovery device. This tool operates by leveraging centrifugal forces generated during fluid swirl to separate liquid from gas. The study examined the performance of IVT under various operational conditions and sought to identify optimal structural parameters. Through a controlled variable approach, the impact of inlet velocity and the water-gas volume ratio on pressure drop range, MGV (maximum gas velocity), and MVFLP (maximum liquid phase volume fraction) was analyzed. The results indicated that when the inlet velocity is between 2-4m/s and the water to gas volume ratio is between 0.5-2m3/104m3, the smaller the inlet velocity and the smaller the water to gas volume ratio, the better the gas-liquid separation effect of the IVT. An orthogonal test was subsequently employed to fine-tune the tool's structural parameters for different conditions, culminating in the creation of a comprehensive optimization chart for IVT. This study can effectively design drainage gas production tools for gas wells under different working conditions, reduce energy loss during drainage gas production, effectively utilize downhole resources, and achieve the goal of increasing natural gas well production and reducing costs.

Research of Heat Transfer Characteristics of Supercritical CO2 in Spiral Tube Heat Exchangers

The spiral tube heat exchanger has the advantages of stable structure, high space utilization rate, and strong heat transfer ability. Supercritical carbon dioxide (s-CO2) has the advantages of high thermal conductivity, high specific heat capacity, and low viscosity. When the spiral tube heat exchanger uses supercritical carbon dioxide as the heat transfer medium, the two complement each other’s advantages and can further improve the heat transfer efficiency and optimize the space utilization rate. However, under the coupling influence of factors such as centrifugal force and buoyancy force, the heat transfer process of s-CO2 in the spiral tube is extremely complex. At present, there is no design criterion or empirical correlation with strong universality in the industrial field. Based on this, this paper mainly uses ANSYS FLUENT, a numerical simulation software suitable for numerical simulation, to study the influence of internal vortex field and secondary flow intensity on the thickness of thermal boundary layers through a combination of numerical simulation and theoretical analysis. At the same time, by changing various operating and structural parameters, the heat transfer characteristics of supercritical s-CO2 in the spiral tube heat exchanger are analyzed and summarized. In addition, we also established a new buoyancy factor, Fu, and tested that when Fu < 1.6 × 10−5, the effect of the buoyancy lift in the pipeline disappeared. At the same time, a correlation formula for predicting the heat transfer performance of spiral tube heat exchangers with a Nu number error less than 20% is established in this paper, which can provide solid theoretical guidance for industrial application.

Research on the Internal Flow and Cavitation Characteristics of Petal Bionic Nozzles Based on Methanol Low-Pressure Injection

This paper aims to discuss the internal flow and cavitation characteristics of petal bionic nozzle holes under different injection pressures to improve the atomization effect of methanol. The FLUENT (v2022 R1) software is used for simulation. The Schnerr-Sauer cavitation model in the Mixture multiphase flow model is adopted, considering the evaporation and condensation processes of methanol fuel to accurately simulate cavitation and internal flow performance. The new nozzle hole is compared with the ordinary circular nozzle hole for analysis to ensure research reliability. The results show that the cavitation of the petal bionic nozzle hole mainly occurs at the outlet, which can enhance the atomization effect. In terms of turbulent kinetic energy, the internal turbulent kinetic energy of the petal bionic nozzle hole is greater under the same pressure. At 1 MPa, its outlet turbulent kinetic energy is 38.37 m2/s2, which is about 2.3 times that of the ordinary circular nozzle hole. When the injection pressure is from 0.2 MPa to 1 MPa, the maximum temperature of the ordinary circular nozzle hole increases by about 33.4%, while that of the petal bionic nozzle hole only increases by 12.3%. The intensity of internal convection and vortex is significantly reduced. The outlet velocity and turbulent kinetic energy distribution of the petal bionic nozzle hole are more uniform. In general, the internal flow performance of the petal bionic nozzle hole is more stable, which is beneficial to the collision and fragmentation of droplets and has better uniformity of droplet distribution. It has a positive effect on improving the atomization effect of methanol injection in the intake port of methanol-diesel dual-fuel engines.

A new method to improve the thermal performance of high-level water collecting cooling tower based on the migration of vortices

This study proposes a novel annular inlet hat structure designed to address internal vortex flow within high-level water collecting cooling towers (HCTs). To investigate the effect mechanism of inlet hat, a three-dimensional numerical model for an HCT equipped with inlet hat was developed, allowing for a comprehensive analysis of the flow and temperature fields, as well as several performance parameters. The results manifest that the inlet hat strengthens the tower thermal performance by migrating the longitudinal vortices from the interior to the exterior and reducing the number of longitudinal vortices induced by crosswinds. The strengthening effect of inlet hat shows minimal variation when its width exceeds 8 m. Under the studied water flow rates, an 8-m inlet hat results in increases in air mass flow rate, water temperature drop, Merkel number, and evaporation rate by a maximum of 4.3 %, 4.2 %, 6.4 %, and 1.5 %, respectively. In terms of crosswinds, the inlet hat operates with optimal efficiency at a direction of 0° and a velocity of 13 m/s, achieving maximum increases in air mass flow rate, water temperature drop, and Merkel number of 23.3 %, 25.4 %, and 33.6 %, respectively. These findings demonstrate the feasibility and practical value of the proposed inlet hat.

A study on the internal vortex structure within a single-blade pump via numerical methods and particle image velocimetry experiments

This study investigates the performance and internal flow characteristics of a single-blade centrifugal pump through a comprehensive analysis integrating performance tests, Particle Image Velocimetry (PIV) tests, and numerical simulations. Across the operational speed range of 1470–2940 rpm, the predicted pump (head-flow rate curve)performance error between the numerical simulation results and the test results of the pump underrated flow conditions is found to be only 3.4%, demonstrating the high accuracy of the selected numerical method in predicting both performance metrics and internal flow structures. Key findings highlight the presence of significant circumferential and axial secondary flows in the region where the blade wraps back, resulting in the formation of high-intensity vortex structures and subsequent energy dissipation. The interaction of the blade's trailing jet with the volute casing's tongue induces periodic changes in the intensity and spatial size of these vortex structures. Furthermore, pronounced reverse vortex pairs are identified within the volute casing, attributed to axial non-uniformity in impeller outflow. These vortex pairs are associated with the preferential accumulation of solid particles, potentially contributing to wear in the volute casing of single-blade centrifugal pumps. The revelation of the evolution characteristics of vortex structure in single-blade centrifugal pumps provides theoretical support for reducing pressure pulsation and radial force of single-blade centrifugal and provides a potential solution to the technical difficulties of low efficiency and poor stability of single-blade centrifugal pumps. Overall, this study provides valuable insights into optimizing the design and operational efficiency of single-blade centrifugal pumps by elucidating their complex flow dynamics and performance characteristics under varying operational conditions.

Numerical analysis of pressure fluctuations in hump region of a pump-turbine

Abstract To reveal the pressure fluctuation characteristics in hump region of a pump-turbine, unsteady simulation for the whole flow passage, based on the SST k-w model, was performed on a pump-turbine model. This study analyzed the time-frequency characteristics and variation laws of pressure fluctuations in different flow passage components, and explored the relationship between pressure fluctuations and internal flow in the vaneless space, guide vane and draft tube. The results indicate that pressure fluctuations in the vaneless space primarily include the blade passing frequency of 7fn and its harmonics, and a low-frequency component of 0.15fn caused by rotating stall. Particularly, rotating stall has the greatest impact on pressure fluctuations in the guide vane. As the flow rates decreased, flow separation intensified and pressure fluctuations increased gradually. The frequencies of pressure fluctuations in the runner include runner rotation frequency of fn and its harmonics, rotor-stator interaction frequency of 20fn, and others related to internal vortices (1.45fn and 2.9fn). In the guide vane, spiral casing, and draft tube, the dominant frequencies were low-frequency components of 0.15fn and 0.1fn, and its amplitude in the spiral casing and draft tube was approximately 5% and 10% of that in the guide vane.

Leidenfrost Effect-Induced Chaotic Vortex Flow for Efficient Mixing of Highly Viscous Droplets.

Efficiently mixing highly viscous liquids in microfluidic systems is appealing for green chemistry such as chemical synthesis and catalysis, but it is a long-standing challenge owing to the unfavorable diffusion kinetics. In this work, a new strategy is explored for mixing viscous droplets by harnessing a peculiar Leidenfrost state, where the substrate temperature is above the boiling point of the liquid without apparent liquid evaporation. Compared to the control experiment where the droplet stays at a similar temperature but in the contact boiling regime, the mixing time can be reduced significantly. Moreover, it is demonstrated that the liquid mixing originates from the chaotic convection flow in the Leidenfrost droplet, characterized by the internal vortex motion evidenced by the microscale visualization. A correlation between mixing time and droplet volume is also proposed, showing a good agreement with experimental results. It is further shown that Leidenfrost droplets can be used to synthesize nanoparticles of the desired morphology, and it is anticipated that this simple and scalable fabrication approach will find applications in the biological, pharmaceutical, and chemical industries.

Study on partial load vortex and pressure pulsation characteristics of Francis turbine

Abstract Under partial load condition of the Francis turbine, problems such as hydraulic vibration, noise, and high amplitude pressure pulsation that endanger the safe and efficient operation of the unit are inevitable during the transient process. Based on dynamic grid technology and CFD technology, unsteady numerical simulation was conducted for the closing process of the active guide vane from 54% opening to 38% opening, and the evolution characteristics of internal vortex and pressure pulsation were analyzed. The results show that there is always a vortex structure at the crown of the runner during the transition process of variable load. Because of the vortex structure, a “banded” low-pressure zone appears on the suction surface of the blade, which gradually approaches the lower ring of the runner as the vortex structure develops. The analysis of the pressure signal in the runner region shows that the pressure coefficient on the suction surface fluctuates greatly due to the influence of the distribution position of the vortex structure, and the evolution of the vortex structure from continuous to local fracture will lead to a sudden increase of the pressure coefficient. In addition, the frequency components within the runner domain include the frequency of the movable guide vanes passing through the blade and the low-frequency components caused by the evolution of eddy currents within the runner.

Influence of Scallops on Windage Loss and Flow Characteristics in Disk-Type Gap

Abstract Windage loss and flow characteristics in a disk-type gap featuring scalloped structures are investigated in this paper. Special attention is paid to the size of the scallops and the associated loss models. The respective losses and scallop effects in the gap are explored with various combinations of depths, quantities, and rotating speeds. The results indicate that scallop structures positively contribute to increased windage losses, accounting for more than 60% of the overall losses. An internal spiral vortex band is formed along the scallop wall, with the scallop depth ratio exerting influences on loss, reaching a maximum of 8.1%. The current scallop loss model overlooks the consideration of the total arc length ratio of scallops to the circumference, presenting a limitation, and the maximum relative deviation from numerical simulation results is observed to be 111.4%. An increase in arc length ratio results in a higher total loss, although the loss per individual scallop is diminished, manifesting in reduced vortices and pressure differences. Furthermore, a modified model is proposed to increase the precision of the current loss model. The maximal relative deviations of 13.8% confirm that the modified model is accepted to predict the windage loss in disk-type gaps with scallops. The conclusions offer valuable insights into the structural design of impellers and high-speed electrical machines with superior efficiency.

3D printed compliance tool incorporated internal-impeller structure for high performance face grinding of titanium alloy

During compliant face grinding of difficult-to-machine areas like the blade runner surface, significant heat accumulation at the tight interface between the workpiece and tool. This leads to limitations in surface integrity and tool life longevity. This study introduces a novel cooling method that incorporates an axially rotating impeller into the cavity of a small compliant grinding tool. The internal impeller structured compliant tool was prepared base on additive manufacturing. Numerical simulations and experimental studies were carried out to investigate its heat transfer mechanisms and its effect on the continuous grinding performance. The findings indicate that while favorable surface roughness and high material removal rates coincide with elevated grinding temperatures, the Shore hardness of the flexible material decreases as the grinding temperature rises. Consequently, there is a reduction in grit cutting depth and an increase in the proportion of rubbing and ploughing grit due to the grit’s height rearranges. The designed internal impeller facilitates the external cooling air with internal vortices to reach the grinding interface zone limiting heat accumulation to below 91.0°C and removing chips to reduce grit adhesion. Consequently, the grinding performance was more consistent, with a stable material removal depth ranging from 97 µm to 103 µm. 3D-printing-based compliant tools provide new insights into consistently high grinding performance for complex parts.

Effect of turbulent integral scale on non-Gaussian characteristics of surface wind pressure on square cylinder

This study investigated the statistical properties of the pressure fluctuations on a square cylinder across three distinct turbulence fields characterized by varying turbulent integral scales. The effect of turbulent integral scale on the non-Gaussian characteristics and extreme surface wind pressure acting on square cylinders beneath the separating flow were studied in detail. The findings indicated that the pressure distribution on the windward surface generally conformed to a Gaussian distribution, whereas notable non-Gaussian characteristics were observed in the pressure distribution on the side and leeward surfaces. The fluctuating pressure, skewness, kurtosis, peak factor, and extreme pressure increase with an increasing ratio of turbulent integral scale to structural depth (Lux/D), whereas the mean pressure remains unaffected by variations in Lux/D. As Lux increased, the energy of the internal vortices in the shear layer also increased. As a result, the non-Gaussian features of the pressure caused by vortex breakdown become more pronounced. Compared with Lux/D = 1.96, the underestimated value of the extreme pressure on the square cylinder had a maximum difference of up to 15.4% at Lux/D = 0.53. Therefore, the corresponding turbulent integral scale should be accurately simulated when measuring wind loading on a structure through wind tunnel tests.

The nonlinear evolution of two surface quasi-geostrophic vortices

We investigate numerically the evolution of a baroclinic vortex in a two-level surface quasi-geostrophic model. The vortex is composed of two circular patches of uniform buoyancy, one located at each level. We vary the vortex radii, the magnitude of buoyancy, and the vertical distance between the two levels. We also study different radial profiles of buoyancy for each vortex. This article considers two main situations: firstly, initially columnar vortices with like-signed buoyancies. These vortices are contra-rotating, are linearly unstable and may break. Secondly, we consider initially tilted vortices with opposite-signed buoyancies, which may align vertically. Numerical experiments show that (1) identical contra-rotating vortices break into hetons when initially perturbed by low azimuthal modes; (2) unstable, vertically asymmetric, contra-rotating vortices can stabilise nonlinearly more often than vertically symmetric ones, and can form quasi-steady baroclinic tripoles; (3) co-rotating vortices can align when the two levels are close to each other vertically, and when the vortices are initially horizontally distant from each other by less than three radii; (4) for initially more distant vortices, two such vortices rotate around the plane center; and(5) in all cases, the vortex boundaries are disturbed by Rossby waves. These results compare favorably to earlier results with internal quasi-geostrophic vortices. Further modelling efforts may extend the present study to fully three-dimensional ocean dynamics.

Optimization of Impeller Structure Parameters of a Centrifugal Fan in a Powered Air-Purifying Respirator Power System

As the core power element of a centrifugal fan, the impeller’s structural parameters are important factors affecting the aerodynamic performance of the fan. Therefore, to improve the aerodynamic performance of centrifugal fans, in this study, we take the Powered Air-Purifying Respirator (PAPR) power system as the object of research and use a combination of computational fluid dynamics (CFD) and experimental validation to investigate the effects of the number of blades, blade inlet angle, blade outlet angle, blade height, and blade thickness on the aerodynamic performance of the fan. A five-factor, four-level orthogonal test table L16 (45) was selected to obtain the optimal combination of structural parameters for the impeller. In addition, in order to identify and visualize the features of the vortex, Q Criterion Normalized is applied to the simulation on the basis that the minimum pressure appears in the vortex core. In this study, Q Criterion Normalized is used to compare the internal vorticity of the prototype with that of the optimized prototype. The results show that (i) the order of influence of each parameter on the aerodynamic performance of the centrifugal fan is blade height > blade outlet angle > blade inlet angle > number of blades > blade thickness; (ii) the optimal combination of the structural parameters is number of blades 48, blade inlet angle 80°, blade outlet angle 120°, blade thickness 0.6 mm, and blade height 23 mm; the optimized prototype has an increase in air pressure of about 10%, an increase in air volume of about 31%, and an increase in efficiency from 49.61% to 53.57%; (iii) the intensity of internal vortices in the optimized prototype is weakened, the size of vortices and the number of vortices are reduced, and the homogeneity of the flow field is also improved.

Effects of guide vane angle on internal flows and vortex characteristic of reactor coolant pump passage under flow coastdown

Effects of guide vane angle on internal flows and vortex characteristic of reactor coolant pump passage under flow coastdown

Investigation on unstable flow characteristics and energy dissipation in Pelton turbine

The internal flow scale of a Pelton turbine is variable, and the interaction between the jet and the bucket has strong transient characteristics, resulting in an incomplete understanding of its internal vortex structure evolution and energy dissipation mechanisms. In order to reveal the influence of vortices on the flow regime and energy dissipation mechanisms in the turbine, this paper establishes the correlation between the unsteady flow characteristics and energy dissipation inside the Pelton turbine based on the energy balance equation and quantifies the energy losses inside the turbine. The results indicate that vortex structures present a non-uniform distribution inside the jet, which disrupts the uniformity of the jet velocity distribution, resulting in an uneven distribution of high-vorticity zones on the bucket surfaces and intensifying flow interference among the buckets. The strong shear flow caused by the downstream flow detachment of the needle guide, the turbulent boundary layer on the jet surface, and the wake effect downstream of the needle tip are the main reasons for the dissipation of fluid kinetic energy. The distribution range of energy loss on the rotating bucket closely corresponds to the position of the high-vorticity zone. Energy dissipation inside the turbine is primarily in the form of turbulent kinetic energy, and the injectors and runner are the primary energy dissipation components. Moreover, inside the injectors, each form of energy loss remains relatively constant, whereas inside the runner, its rotation induces fluctuating energy losses attributed to Reynolds stress work. The results contribute to an enhanced understanding of the energy dissipation characteristics and complex flow mechanisms within the turbine, providing reference for the optimisation and efficient operation of the multi-nozzle Pelton turbine.

Research on the Internal Flow Difference between Peak and Valley Conditions of Water Jet Propulsion Pump during Working at Hump Region

When we tested the water jet propulsion pump, we found that there were significant vibrations in the pump, especially at small flow points that deviated from the design conditions. The water jet propulsion pump is a mixed-flow pump with guide vane, which is commonly employed for water jet propulsion. However, the guide vane mixed-flow pump is susceptible to a phenomenon known as “hump”, which can cause flow disturbances, increased vibration, and noise when the pump operates within the hump region. According to the vibration phenomenon found in our experiment, the mechanism of vibration needs to be revealed. This study focuses on vorticity and turbulence distributions of a mixed flow water jet propulsion pump under the valley and peak operating conditions of the hump region. The research is conducted using experimental and numerical simulation methods. The SST k-ω turbulence model is employed for turbulence calculations. The experiments are conducted on a closed test rig for axial (mixed) flow pumps. A comparison of experimental and numerical simulation results of hydraulic performance curves are conducted to validate the accuracy of the numerical simulation. Cavitation flow structures of the critical cavitation stage under valley conditions and under peak conditions are compared. A comparative analysis is conducted to examine the differences in internal vortex core distribution and turbulence kinetic energy distribution between the valley and peak operating conditions when working within the hump region. The pressure and velocity vectors of the pump impeller blades and the velocity streamline distribution between the impeller and the guide vane blades are compared. To further analyze the flow state in different flow channels under valley and peak conditions, the streamline distribution at Span = 0.5 in the impeller and diffuser basin is extracted. This study provides theoretical foundations and technical support for the design of high-performance, low-vibration water jet propulsion pumps.

Study on the mechanism of sessile droplets evaporation enhanced by the electric field

The evaporation characteristics of a sessile droplet under a direct current electric field were numerically investigated, and a numerical model was developed based on the arbitrary Lagrange-Euler method, combining the flow, heat transfer, vapour transport, and electrostatic equations. The simulations were validated to be in good agreement with previously reported experiments. The results demonstrate that the electric field can enhance the evaporation of the sessile droplet with different evaporative cooling numbers (initial electric field intensity E0 = 280 kV·m−1; 32.9% decrease in the evaporation time for water) by the following three methods: increasing the surface area of the droplet evaporation (2.6%) through the electric-field-induced deformation, improving the heat transfer efficiency between the droplet and substrate (droplet average temperature increases by 2.3 K) through the internal vortex, and by enhancing the shearing effect on the vapour layer (450.3% increase in vapour diffusion distance dc) through the external vortex. Additionally, the evaporation of a sessile water droplet undergoing thermocapillary convection is further enhanced under the electric field (E0 = 280 kV·m−1; 20.0% decrease in the evaporation time). As the inhomogeneous temperature distribution inside the droplet was eliminated by thermocapillary convection, the evaporation efficiency was dominated by the increased surface area of the droplet evaporation and the enhanced shearing effect on the vapour layer. These results will provide a better understanding of the electro-hydrodynamic enhanced droplet evaporation.

Review and Analysis of the Characteristics of IoT Sensors

Internet of things (IoT) is the concept of data transmission network between physical objects ("things"), equipped with built-in tools and technologies for interaction with each other or with the environment. The work is devoted to the inspection and analysis of sensors, how the IoT systems are associated with environmental objects. IOT uses a wide class of measurement tools, from elementary sensors (eg, temperature, pressure, light), consumption metering devices (such as intellectual meters) to complex integrated measuring systems. The parameters of 30 types of sensors for IoT are given, 2 of them of the type of temperature and humidity sensors, 2 type of pressure sensors, 13 sensors that measure the flow and amount of gas or liquid, 2 type of accelerometers, 10 approach and movement sensors and 1 noise sensor. Among them are 4 sensors for wireless sensory networks (WSM), a single-time medical sensor for internal blood pressure measurement, calorimetric, vortex and electromagnetic flow sensors and gas or fluid, accelerometer, and memes of memes, and e-memometers, and electromagnetic measurement motion, a device of measuring noise level in the range of sound vibrations. For some sensors, there are no metrological characteristics at all, at best there is only a range of measurements and resolution. The resolution ranges from 8 bits to 16 bits with a signal sampling rate from 0.5 Hz to 48 kHz. There is even a LDC1612 digital induction chip with 28 bits. WSM sensors are designed to work with DigiMesh, LoraWan and Arduino, Raspberry. Many sensors use outdated RS 232, RS 432, I2C. Keywords: internet of things, network, review, analysis, sensors, objects, metrology.

Study on motion characteristics of filamentous biomass particles in a cyclone separator

Cyclone separators are important equipment for biomass transportation and separation. At present, the separation mechanism of particles with special shapes is rarely explored. A mutable filamentous particle was established to simulate the separation process of biomass materials. Firstly, comparing the simulateded results with the experimental images. Further comparison of the simulation results with the experimental airflow tangential velocity to verify the calculation model. This study explores the separation characteristics and forces acting on filamentous biomass particles through computational fluid dynamics (CFD) and discrete element method (DEM). The distribution characteristics of airflow are also described in detail. The research results indicate that after 0.8 s, the filamentous biomass particles are separated stably in the cyclone separator and form a particle vortex line on the conical wall. The higher the inlet gas velocity, the lower the separation efficiency of filamentous biomass particles. The inlet gas velocity is 4.9 m/s, and the separation efficiency of filamentous biomass particles reaches 98.7%. The total force acting on the filamentous biomass particles gradually decreases after a sharply increase at 0.2 s, and it no longer changes after 0.5 s. The airflow vortex in a cyclone separator is composed of an internal vortex and an external vortex. The tangential velocity of the internal vortex varies approximately linearly. The internal vortex of the cyclone separator has a negative pressure area, which can lead to a decrease in the separation efficiency of filamentous biomass particles. These conclusions provide valuable theoretical guidance for the process and separation of biomass materials.