ANSYS CFX Software Research Articles

CFD investigation of multiple peristaltic waves in a 3D unobstructed ureter

Ureters are essential components of the urinary system and play a crucial role in the transportation of urine from the kidneys to the bladder. In the current study, a three-dimensional ureter is modelled. A series of peristaltic waves are made to travel on the ureter wall to analyse and measure parameter effects such as pressure, velocity, gradient pressure, and wall shear at different time steps. The flow dynamics in the ureters are thoroughly analysed using the commercially available ANSYS-CFX software. The maximum pressure is found in the triple wave at the ureteropelvic junction and maximum velocity is observed in the single and double wave motion due to the contraction produced by the peristalsis motion. The pressure gradient is maximum at the inlet of the ureter during the single bolus motion. The contraction produces a high jet of velocity due to neck formation and also helps in urine trapping in the form of a bolus, which leads to the formation of reverse flow. Due to the reduction in area, shear stress builds on the ureter wall. The high shear stress may rupture the junctions in the ureter.

MODIFICATION OF THE CENTRIFUGAL PUMP IMPELLER USING CAD

Currently, during the design of hydraulic machines, specialized software is widely used. The work presents an overview of modern programs that use a system of automated design of centrifugal pumps. The modern approach to the design of centrifugal pumps is based on the joint solution of direct and inverse problems of the theory of the working process in hydraulic machines. The purpose of the work is to develop the impeller of a centrifugal sectional pump with the following parameters: a liquid volume of 6 m3 per hour and a pressure of 140 m. The pump is used to supply crude oil to the recuperators of the small distillation unit SDU-20 of the oil refinery. In the sectional pump, it is possible to compose packages of impellers of various designs. The lack of publicly available geometric dimensions of the impeller of a centrifugal sectional pump for the required parameters makes it difficult to choose an effective mode of operation. Therefore, the task of designing and researching the impellers of the VNS type pump using CAD in the ANSYS CFD software environment is relevant. The work uses the free academic version of ANSYS CFD. The work presents a description of the main stages of design and research of a centrifugal pump. The geometric dimensions and kinematic parameters of the pump were analyzed and selected according to the jet classical theory and calculation results in the Vista CPD program. The overall efficiency of the pump at the preliminary design stage reaches 50 %. At the second stage, the direct task of computer 3D modeling in the Ansys CFX software environment is solved. Determination of the hydrodynamic and energy characteristics of the pump is carried out. The paper presents the results of a numerical study of three variants of the pump impeller, which are used to predict the mode of efficient operation of a centrifugal pump.

Numerical and experimental study of a multiphase flow inside a self-contained drum motor drive system

The multiphase Taylor-Couette flow of air and oil enclosed within the annular space between two concentric cylinders has been studied experimentally and numerically. The outer cylinder rotates at a constant speed and exchanges heat by convection and radiation with ambient air. The inner cylinder is stationary and subjected to a constant uniform heat flux. Such flow can be found in a self-contained drum motor drive system (SCDMDS). The heat flux imposed on the inner cylinder mimics the amount of heat generated due to several thermal losses within the SCDMDS. A layer of lagging material is sometimes added to the outer cylinder to enhance belt traction.The effect of the inner-to-outer cylinder radius ratio (RR), Reynolds number (Re), oil volume (OV), outer cylinder surface emissivity (ε), and lagging material thickness (δ) on the flow and heat transfer between the two cylinders and the ambient has been investigated considering a quasi-steady state analysis. The current investigation considered the following ranges found in a typical SCDMDS: RR = 0.35–0.85, Re = 200–3000, OV = 50–100 %, ε = 0–0.95, and δ = 0–100 mm. The numerical part of the present study has been carried out using ANSYS-CFX software package. The numerical results have been validated using experimental data. Resultsindicated that increasing RR, Re and ε enhanced the heat transfer within the SCDMDS. The rate of heat transfer within the annular space reached its highest value at OV = 65 % above which the rate of heat transfer is deteriorated. Because the lagging material is acting as an insulation over the outer cylinder, a critical thickness of δ = 35 mm resulted in the minimum overall resistance above which the rate of heat transfer is deteriorated.The parametric study revealed that the best overall thermal performance was attained at RR = 0.85, Reynolds number = 3000, OV = 65 %, ε = 0.95 and δ = 35 mm. In this case, the heat transfer coefficient between the inner cylinder and the oil reached its highest value of 410 W/m2 °C, giving the lowest possible inner cylinder temperature. A correlation of Nusselt number in terms of the geometrical and operating parameters of a SCDMDS considered in the current study has been developed and validated. The developed correlation gave a maximum deviation of ±8 %.

Archimedes Screw Pump Efficiency Based on Three Design Parameters using Computational Fluid Dynamics Software – Ansys CFX

Utilization of Archimedes screw pumps as water lifting pumps has become widespread in past decade due to frequent occurrences of floods in Malaysia. The problem of insufficient drainage in various urban areas exacerbates the impact of heavy rainfall, prompting efforts to mitigate this issue with minimal maintenance cost and low impact to the environment. Thus, this study is aiming to study the design parameters of screw pump to obtain the optimal efficiency of the Archimedes screw pump specifically for flood mitigation in Malaysia. The main design parameters affecting pump’s efficiency are rotor profile, pitch length, length of the pump, rotational speed, inclination angle, and material selection. However, only three design parameters were considered in the study, that are the angle of inclination, the number of blades, and the angular velocity of the rotating pump. These three design parameters are selected as many previous findings focusing on varying angle of inclination with number of blades with constant rotational speed. Thus, this study will find the highest efficiency when these three design parameters are integrated with variation of rotational speeds at 25, 30 and 40 RPM. Basically, screw pump is designed using SOLIDWORKS and simulations with specific boundary conditions are conducted using the ANSYS-CFX software, which utilizes computational fluid dynamics (CFD) techniques. These boundary conditions are based on previous study by Rosly et al in 2016. The inlet flow rate of 0.002 m3/s and diameter of the screw pump are constant while the other three main parameters are varying within the acceptable ranges which are reported from prior studies. The outcomes found that the highest torque is generated by a single rotating blade at 5.65 Nm which rotates at 30 RPM at 30° angle of inclination. Meanwhile, the highest efficiency of 24.04% is obtained with a single rotating blade at 40 RPM with 20° angle of inclination. Based on the findings, it is concluded that these three main design parameters of screw pump may not be sufficient to obtain the optimal efficiency for the specific boundary conditions used in the simulation study. Thus, several combinations of design parameters should be considered in the future to increase the screw pump’s efficiency.

Modeling of heat exchangers in ANSYS CFX for the digital twins development

The paper presents a universal methodology for modeling and optimization of shell-and-tube heat exchanger designs using the ANSYS CFX software package. Mathematical modeling plays a key role in the design and modernization of heat and mass transfer equipment, especially in the petrochemical and oil and gas processing industries, and especially in the creation of digital twins of heat and mass transfer equipment. The modern approach provides prediction of equipment behavior at the development stage, which makes it possible to take into account the peculiarities of the actual geometry of the apparatuses and optimize the interaction of contacting phases. The paper considers the stages of creating a digital model of a heat exchanger, including the construction of an electronic geometric model, creation of a computational grid, selection of mathematical models of hydrodynamics and heat transfer, as well as the setting of boundary conditions and solver parameters. Special attention is paid to the selection of heat transfer and turbulence models suitable for high Reynolds numbers. The results of numerical simulation in ANSYS CFX are compared with analytical solutions and data obtained with ANSYS Fluent. The difference in the results was about 1 °C, which confirms the high accuracy and reliability of the proposed methodology. This indicates the feasibility of using ANSYS CFX for modeling and optimization of technological equipment. The obtained results can be applied to build a digital twin model, to improve the efficiency of heat transfer processes, to reduce the cost of development and modernization of equipment, as well as in further research on the intensification of heat and mass transfer using digital models.

Numerical and experimental investigations on a bladeless turbine: Tesla's cohesion-type innovation

The design, numerical simulation, manufacturing, and physical experimentation of Tesla's bladeless centripetal turbine for electrical power production are the topics of this research project. The turbine generates rotational motion in the discs by directing pressurized air and water tangentially across parallel smooth disc surfaces. The fluid speed parameter at the nozzle inlet determines the power generated. To ensure optimal mechanical design parameters, SolidWorks design software, fluid dynamics concepts, and machine element design were employed. The numerical simulation software ANSYS CFX was used. The numerical and qualitative findings of the models and physical experiments coincided well. The study revealed that the power production and turbine efficiency were regulated by the input sources and blade size. Variations in the fluid composition between the discs may additionally have an impact on the outcomes. The researchers investigated the connection between input fluid pressure and turbine efficiency, as well as the number of discs and turbine power. The prototype could generate 76.52 W of electricity at 50 bar pressure and 1.01e+05 Reynolds number. The operation was efficiently simulated using CFD, with only a 9.3% difference between experimental and simulated results. Overall, this research provides an in-depth assessment of Tesla's bladeless centripetal turbine. It verifies the design and numerical simulation methodologies used, as well as identifies the essential aspects impacting turbine performance and efficiency. The findings contribute to a better understanding of the turbine's behavior and give ideas for improving its performance.

Investigation of water phase change rotating cooling for high temperature turbine

Thermal protection of high temperature turbine restricts the performance of gas turbine. In order to increase turbine inlet temperature, water phase change rotating cooling scheme for turbine was proposed for using the gasification latent heat to improve cooling capacity. Numerical model of phase change rotating cooling was established to study the flow and heat transfer characteristics with Ansys CFX software using SST k-ω turbulence model. Results showed that phase change rotating cooling had good performance for cooling the rotating blades. The temperature drops of blades were more than 400 K with the average heat flux of 2.42 MW/m2. Due to the influence of flow thermal acceleration effect, the outlet pressure of cooling channel reached a maximum value of 7.23 MPa with a mass flow rate of 0.17 g/s. The outlet quality distribution under rotating condition was relatively uniform than nonrotating condition. The temperature increased firstly and then decreased in centripetal channel along phase change process because of pressure variation. Meanwhile, gas-liquid interface disappeared due to the Coriolis force, resulting in higher heat transfer coefficient than static condition. The normalized Nusselt number (Nus) of phase change rotating cooling reached 3.915, much higher than static liquid cooling.

Numerical investigation of injection characteristics on normal saline irrigation quality in curved root canals using computational fluid dynamics

ObjectivesThe primary aim of this research was to find the effects of Normal saline injection rate and position on irrigation quality in curved root canals. MethodsComputational Fluid Dynamics (CFD) was used to simulate irrigation in root canals. Root canal geometries were obtained by considering the complete shaping of a rotary file in four root groups with 0, 10, 30, and 60° of curvatures. Fluid surface tension, bouncy, gravity, and air entrance were considered in the numerical simulation using Ansys-CFX software. For each root canal, the flow regime and wall shear stresses were calculated at three different syringe plunger speeds, and three different injection locations of a beveled open-ended needle and their effects on the irrigation quality were investigated in this paper. ResultsWall shear stress is considered the main parameter determining irrigation quality. It was calculated for all 36 test cases. Injection rate and normal saline accumulating near the apex and their effects on washed area ratio were shown for the test cases. Results showed significant effects of injection characteristics, incredibly faster injection, and deeper needle position on the irrigation quality of curved root canals. ConclusionsA higher injection rate and deeper needle position are required to achieve the best irrigation quality and a more washed area ratio in root canals with greater curvature.

CFD Analysis on the Development of Pre-Duct Shape to Improve Propeller Performance

Energy saving contributions of Energy Saving Device (ESD) Pre-Duct are reducing energy losses and separation at the stern, increasing the ideal propeller efficiency, increasing the capture of viscous wake that passes through the propeller disk, and increasing the interaction of the propeller and ship hull. The effect of ESD Pre-Duct in front of the propeller on saving of energy is influenced by the accuracy and suitability of the geometry, position, and shape of pre-duct. In this study, the shape of the asymmetric un-circular pre-duct was develop and analysis conducted by compared the effect of the shape of pre-duct on the performance of propeller, the shape of pre-duct: circular (conventional), un-circular, and asymmetric un-circular. Computational Fluid Dynamics (CFD) modelling results using the ANSYS CFX software package with Propeller Open Water (POW) test simulations show that the installation of pre-ducts with several shape developments in general has a significant effect on increasing propeller performance at low propeller rotation speeds, whereas on high propeller rotation even though there is an increase in propeller performance but not significant.

A Novel Design of Centrifugal Pump Impeller for Hydropower Station Management Based on Multi-Objective Inverse Optimization

The impeller, regarded as the central component of a centrifugal pump, plays a pivotal role in dictating overall performance. Overcoming challenges arising from the complexity of design parameters and the time-intensive nature of the design process has been a persistent obstacle to widespread adoption. In this study, we integrated ANSYS-CFX 2023 software with innovative inverse design techniques to optimize the impeller design within a centrifugal pump system. Our investigation reveals groundbreaking insights, highlighting the significant influence of both blade load and shaft surface geometry on impeller performance. Notably, through load optimization, substantial enhancements in centrifugal pump efficiency were achieved, demonstrating improvements of 1.8% and 1.7% under flow conditions of 1.0 Q and 0.8 Q, respectively. Further, the efficiency gains of 0.44% and 0.36% were achieved in their corresponding flow conditions. The optimization of blade load and shaft surface configuration notably facilitated a more homogenized internal flow pattern within the impeller. These novel findings contribute substantively to the theoretical foundations underpinning centrifugal pump impeller design, offering engineers a valuable reference to elevate their performance. Our utilization of ANSYS-CFX software in conjunction with inverse design methodologies showcases a promising avenue for advancing impeller design, ultimately culminating in superior efficiency and performance for centrifugal pumps.

Numerical Simulation of Environmental Characteristics of Containment in Severe Accident of Marine Nuclear Power Plant

With the reliance on ocean resources, the nuclear power powers have set their sights on marine nuclear power plants to break through the bottleneck of energy supply for the development of ocean resources. In this paper, the computational fluid dynamics software ANSYS CFX 2021 is used to simulate the TOSQAN benchmark experiment. Three different turbulence models, the k−ε model, RNG k−ε model, and SST model, are selected to analyze the adaptability of the turbulence model. The simulation results are compared with the benchmark experimental results, and the selected numerical calculation model is used to analyze the influence of vapor on the pressure, temperature, hydrogen distribution, and hydrogen risk in the containment space when a hypothetical serious accident occurs in a marine nuclear power plant. The results show that the results simulated with the k−ε turbulence model are closer to the benchmark experimental results. Vapor has no obvious effect on the response speed of pressure balance at each position in the closed containment space, and the condensation of the vapor wall can effectively reduce the pressure peak in the closed containment space. The existence of vapor and the increase in vapor concentration will increase the temperature in the closed containment space. The condensation of vapor on the wall surface will cause the temperature in the containment space to have a peak value, which can effectively reduce the temperature in the containment space. Vapor will promote the mixing of gas in the containment space and make the hydrogen distribution tend to be uniform. The presence of vapor and the increase in vapor concentration can reduce the hydrogen risk in the containment space, but the condensation of vapor may increase the hydrogen risk in the containment space.

Numerical simulation and low speed experiment of a low partially admitted rate axial turbine for small scale organic Rankine cycle

High rotating speed is a prominent feature of turbine used for small-scale organic Rankine cycle (ORC) system, which can bring the problems of safety, reliability, sealing, vibration, economics, etc. Partial admission method has potential to reduce the rotating speed of small turbine. In this study, an axial turbine with low partially admitted rate of 0.033 was tested in ORC loop using R1233zde as working fluid, and numerically researched using Ansys CFX software with k-omega turbulence model. Results showed that the specific powers of turbine resulting from CFD should be corrected with losses to match well with the experimental results. Losses could reduce the optimal rotating speed of turbine. The optimal rotating speed, mass flow rate, power and efficiency of turbine under rated condition were 8000 RPM, 115.8 g/s, 611.8 W and 35.8 %, respectively. The corresponding power and thermal efficiency of ORC were 551.0 W and 2.15 %. The influences of inlet and back pressures on the performance of turbine were different. With constant inlet pressure and temperature, the mass flow rate kept almost unchanged after chocking, but the power continued to increase. Under allowable conditions, reducing back pressure of turbine played an important role in improving turbine performance.

Simulation of energy losses in an inflow turbine with partial blading of the runner

Studying the coefficients of kinetic energy losses of the nozzle diaphragm and the runner in an inflow turbine with partial blading of the runner is carried out. It is noted that inflow low-consumption turbines are reliable and productive devices designed to drive various units. Due to their compact size, they are especially in demand in various branches of mechanical engineering. However, in order to increase efficiency and reduce production costs, it is necessary to constantly improve the technology of manufacturing turbine stages. Some inflow turbines are partial, which leads to additional energy losses. Partial stages in which there are no losses from ventilation, namely, turbines with partial flapping of the runner are considered. To simulate such turbines, the ANSYS CFX software package is used in the work. By using ANSYS Design Modeler to create a geometric model and determine boundary conditions, as well as selecting the appropriate grid, the dependences of the loss coefficients in the nozzle and the runner are obtained. The study has shown that the degree of partiality and the Mach number of the turbine stage have a significant impact on the losses coefficients in the exact part of the nozzle and the runner. To account for these dependencies in the modeling process, empirical dependencies, which are an integral part of the design process of inflow turbines, are obtained. The use of the obtained empirical dependences makes it possible to more accurately predict the characteristics and performance of turbines of this type, as well as to supplement the existing mathematical model of the flow in the flow part of a low-consumption inflow turbine with partial blading of the runner.

CFD investigation of fluid and heat transfer in a single-phase natural circulation toroidal loop

Natural circulation occurs due to a temperature-induced density gradient, typically observed within closed loops where the fluid is heated in the upper section and cooled in the lower section. This phenomenon finds numerous engineering applications, particularly as a passive heat removal mechanism in nuclear reactors, significantly enhancing their safety. However, the computational modeling of natural circulation poses challenges due to its complex, multidimensional, and nonlinear characteristics. Furthermore, in such systems, fluid dynamics and thermal aspects are intricately intertwined. Hence, the objective of this study is to evaluate the fluid and thermal behavior of a toroidal loop under natural circulation using the Computational Fluid Dynamics (CFD) ANSYS CFX package. A 2D model is employed, along with the Boussinesq approximations, as they are well-suited for toroidal systems. Turbulence is calculated using the k−ϵ. Various modified Grashof Numbers (Gr) normalized by the geometric parameter (NG) are utilized, ranging from 5.4×103 to 4.7×105, for two different Prandtl numbers. The lowest Grm/NG value in each simulation represents the convection lower limit (flow initiation), while the highest value indicates the convergence limit, beyond which a steady state cannot be achieved. Temperature and velocity profiles are presented, and their variations with the power level are discussed. The resulting Reynolds of Steady State (Ress) are plotted against Grm/NG values, demonstrating good agreement with experimental data. As the Prandtl Number increases, the system is observed to enter an unstable zone at an earlier stage. Finally, it is observed that multiple steady states exist for Pr=0.7, and their implications are discussed.

Вдосконалення процесу обробки абразивно-повітряним струменем робочих поверхонь лопаток моноколіс закритого типу на основі даних чисельного моделювання за допомогою програмного комплексу ANSYS CFX

The correct choice of technological modes can guarantee the results of inkjet processing. However, the need to consider a significant amount of input data, namely the parameters of the equipment, the abrasive jet, the physical and mechanical properties of the material, and the shape of the processed product surfaces, as well as the lack of clear recommendations and technological data, significantly complicates the process. The subject of this study is the process of processing the surface of closed-type blades with an abrasive-air jet made in one piece with a disk of the "monowheel" type, using the SLM technology of Inconel 718 alloy. The goal of this task is to model the jet processing of closed-type monowheel blades using the ANSYS CFX finite element analysis software system. This article presents the results of numerical modeling of the surface treatment of closed turbine blades and the identification of technological factors that affect the roughness and quality of the surface of the compressed air environment on samples of closed turbine blades made of Inconel 718 alloy. The task: to develop a research plan and study the processing process and accompanying phenomena occurring during processing using the finite element method using the ANSYS CFX software complex, considering the physical and mechanical properties of the abrasive often, the environment, and the processed material. The following results were obtained: during mathematical modeling using the finite element method, data were obtained for sixteen calculation variants of blade surface treatment, from which the most optimal one was chosen, which provides the largest contact area of abrasive particles and their uniform interaction with the processing surface. In addition, during the research, the impact of "unevenness of erosion" and the graininess of abrasive materials on the quality of the treated surface was studied. Further analysis of the data of the research results made it possible to find ways to solve these tasks, which was confirmed by the control and verification results. Conclusions. The scientific novelty of the obtained results is as follows: for the first time, the processing of closed turbine blades made in one piece with a "monowheel" type disk and obtained by the additive method with an abrasive air jet was investigated. The obtained research data were used as a basis for developing a real route technological process for processing closed-type turbine blades manufactured using the additive method.

Simulation of the Hydraulic Performance of Parallel Pivot Weirs with Different Angles

Pivot weirs are one of the most important structures for regulating the water level in rivers and canals. These weirs are constructed with one or more gates in a row in the waterways. Changing the angle of each gate is done individually with an independent system. Based on available information, the hydraulic performance of this type of weirs (especially in several gates and different angles) in different operational conditions has not been investigated. In present study, pivot weirs with two gates are simulated using Ansys CFX software with the angles of 27.8 to 90 degree and the discharges between 40 to 130 L/s. Further, the importance of the open space between the two adjacent weirs with different angles (lack of retail wall) and its hydraulic behavior have been studied. The model was calibrated based on valid laboratory data and using the K-ϵ turbulence model. Therefore, the weirs with equal angles were studied in the first step. In this case, the effective discharge angle coefficient was studied and its maximum value compared to the vertical angle was obtained 1.076 for the angle of 52°. Furthermore, relationships for discharge coefficient versus upstream water depth were developed. In the next step, the effective length of the crest was found to be increases by 30% under unequal angles operation and the discharge coefficient raised by 1.3 to 2.4 times. Also, it was recognized that, in case of two weirs with unequal angles, about 26% to 69% of the flow passes through the distance between the two weirs. Therefore, the performance of unequal angles operation seems to be more effective in controlling the water level and discharge in different conditions and especially in flood events.

Numerical and experimental study of a very low head (VLH) turbine in an open channel at no-load conditions

Very low head (VLH) turbines are axial turbines with the capability of extracting power at a high efficiency of over 80% from very low heads (less than 4.5 m) and high flow rates of up to 30 m3/s per unit, with a significant reduction in construction costs, compared to conventional hydropower turbines. At no-load conditions, the turbine reaches its runaway speed, which is its theoretical maximum speed, causing damage to the equipment and the turbine structure, thereby imposing a considerable financial burden. As a result, understanding the performance of the turbine at the runaway speed is of utmost importance. The present paper centers its experimental and simulation efforts on predicting the runaway speed of the turbine rotor. An experimental study is conducted to determine the relationship between the runaway speed of the turbine and the flow rate, as well as compare its value with the rotational speed at the design point. Through the conducted experiments, it has been observed that at the mass flow rate corresponding to the design point, the runaway speed is 2.12 times higher than the rated value. Transient simulations using Computational Fluid Dynamics (CFD) are employed to investigate the performance under no-load conditions by estimating the generated torque as a key parameter. Simulations are carried out in an open channel configuration using the Ansys CFX software, and the results are compared to the experiments. In this study, a portion of the work focuses on simulating the free surface flow over the turbine, which allows for more realistic simulations of the turbine's operational behavior. The results of these simulations indicate that the homogeneous model is able to correctly predict free surface flow downstream and upstream. The numerical approach can also predict the runaway state of the VLH turbine with high accuracy, exceeding 95%; however, this variation is due to mechanical and hydraulic losses that have not been factored into the simulation. In this CFD modeling, setting up the boundary conditions accurately is vital, especially for the water levels at the inlet and outlet.

Shock wave configuration in a transonic flow through a mid-section of a last stage turbine blade cascade equipped with a part-span connector

This paper deals with the study of a flow field and namely the configuration of shock waves in a blade cascade equipped with a part-span connector called tie-boss. The cascade consists of prismatic blades formed from the mid-section of a very long last-stage blade of a steam turbine. The study is based on numerical simulations of the flow through a cascade that was previously tested in a wind tunnel. Commercial software Ansys CFX was used for the simulations and Ansys ICEM for the mesh generation. The computational domain contains non-homogenous mesh interfaces. The simulations showed that the presence of the tie-boss has a profound effect on the configuration of the shock waves. The blade exit shock waves are disturbed and new lateral shock waves are introduced into the flow.

Multi-Objective Parameter Optimization of Submersible Well Pumps Based on RBF Neural Network and Particle Swarm Optimization

In order to improve the hydraulic performance of a submersible well pump, steady and transient simulations were carried out based on ANSYS CFX software. The head and efficiency of the submersible well pump under standard operating conditions were taken as the optimization objectives, and the impeller outlet placement angle, outlet width, and vane wrap angle were selected as the optimization variables using the Plackett-Burman experimental design method. The RBF neural network training samples were constructed using the uniform experimental design method to build a hydraulic performance prediction model for the submersible well pump, and a multi-objective particle swarm optimization was used to solve the model and obtain the Pareto optimal solution set. Using the head and efficiency of the initial model as the boundary, the Pareto optimal solution and the corresponding structural parameters are sought. After the optimization, the head of the individual with the better head is increased by about 2.65 m, and the efficiency of the individual with the better efficiency is increased by about 2.3 percentage points compared with that of the initial model. The pressure gradient in the impeller flow channel is more obvious, the work capacity is significantly improved, the vortex area of the spatial guide vane is smaller, the flow line is more regular, and the pressure pulsation amplitude at the inlet and outlet of the impeller and the spatial guide vane is significantly reduced.

Aerodynamics Optimization of Multi-Blade Centrifugal Fan Based on Extreme Learning Machine Surrogate Model and Particle Swarm Optimization Algorithm

The centrifugal fan is widely used in converting mechanical energy to aerodynamic energy. To improve the pressure of the multi-blade centrifugal fan used in an air purifier, an optimization process was proposed based on extreme learning machine (ELM) combined with particle swarm optimization (PSO). The blade definition position parameter and blade definition radian parameter were designed using the full-factor simulation experimental method. The steady numerical simulation of each experimental point was carried out using ANSYS CFX software. The total pressure of the multi-blade centrifugal fan was selected as the optimization response. The optimized ELM combined with the PSO algorithm considering the total pressure response value and the two multi-blade centrifugal fan parameters were built. The PSO algorithm was used to optimize the approximation blade profile to obtain the optimum parameters of the multi-blade centrifugal fan. The total pressure was improved from 140.6 Pa to 151 Pa through simulation experiment design and improved surrogate optimization. The method used in the article is meant for improving multi-blade centrifugal total pressure. The coupling optimization of impellers, volutes, and air intakes should be comprehensively considered to further improve the performance of centrifugal fans.