Optimal Design and Aerodynamic Study of Leaned Transonic Axial Flow Fan Rotors

2014 ◽  
Author(s):  
Seyed Reza Razavi ◽  
Masoud Boroomand
Keyword(s):  
Numerical Simulation ◽  
Optimization Problems ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Target Function ◽  
Computer Code ◽  
Optimization Method ◽  
Tangential Direction ◽  
Operating Range ◽  
Safe Operating

Multi-Objective Optimization Problems (MOP) are very usual and complicated subjects in Turbomachinery and there are several methodologies for optimizing these problems. Genetic Algorithm (GA) and Artificial Neural Network (ANN) are the most popular ones to solve MOP. In this study, optimization was done for leaned rotor blades to achieve maximum performance parameters including specifically stage pressure ratio, efficiency and operating range. By bending an existing transonic rotor which is well-known as NASA rotor-67 in tangential direction, effect of leaning on performance and aerodynamic parameters of transonic axial-flow compressor rotors was studied. To understand all effects of lean angle, an organized investigation including numerical simulation of basic rotor, implementation of curvatures on basic rotor, numerical simulation of leaned blades and optimization were applied. Various levels of lean angles were implemented to basic rotor and by employing a three dimensional compressible turbulent model, the operating parameters were achieved. Afterwards, the results were used as input data of optimization computer code. Finally, the ANN optimization method was used to achieve maximum stage pressure ratio, efficiency and safe operating range. it was found that the Optimized leaned blades according to their target function had positive or negative optimized angles and the optimized lean angles effectively increased the safe operating range about 12% and simultaneously increase the pressure ratio and efficiency by 4% and 5%, respectively.

Multidisciplinary Design and Optimizations of Swept and Leaned Transonic Rotor

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Seyed Reza Razavi ◽  
Shervin Sammak ◽  
Masoud Boroomand
Keyword(s):  
Optimization Problems ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Target Function ◽  
Multi Objective Optimization ◽  
Operating Range ◽  
Multi Objective ◽  
The Impact ◽  
Transonic Rotor ◽  
Safe Operating

Optimization problems in many engineering applications are usually considered as complex subjects. Researchers are often obliged to solve a multi-objective optimization problem. Several methodologies such as genetic algorithm (GA) and artificial neural network (ANN) are proposed to optimize multi-objective optimization problems. In the present study, various levels of sweep and lean were exerted to blades of an existing transonic rotor, the well-known NASA rotor-67. Afterward, an ANN optimization method was used to find the most appropriate settings to achieve the maximum stage pressure ratio, efficiency, and operating range. At first, the study of the impact of sweep and lean on aerodynamic and performance parameters of the transonic axial flow compressor rotors was undertaken using a systematic step-by-step procedure. This was done by employing a three-dimensional (3D) compressible turbulent model. The results were then used as the input data to the optimization computer code. It was found that the optimized sweep angles can increase the safe operating range up to 30% and simultaneously increase the pressure ratio and subsequently the efficiency by 1% and 2%. Moreover, it was found that the optimized leaned blades, according to their target function, had positive (forward (FW)) or negative (backward (BW)) optimized angles. Leaning the blade at the optimum point can increase the safe operating range up to 12% and simultaneously increase the pressure ratio and subsequently the efficiency by 4% and 5%.

Optimization Method of the Multistage Axial Compressors Using CFD Simulation

2021 ◽  
pp. 2141006
Author(s):  
Grigorii Popov ◽  
Igor Egorov ◽  
Evgenii Goriachkin ◽  
Oleg Baturin ◽  
Daria Kolmakova ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Optimization Problems ◽  
Search Algorithm ◽  
Pressure Ratio ◽  
Optimization Method ◽  
Cfd Modeling ◽  
Turbine Engines ◽  
Stability Margins ◽  
Axial Compressors ◽  
Cfd Models

The current level of numerical methods of gas dynamics makes it possible to optimize compressors using 3D CFD models. However, the methods and means are not sufficiently developed for their wide application. This paper describes a new method for the optimization of multistage axial compressors based on 3D CFD modeling and summarizes the experience of its application. The developed method is a complex system of interconnected components (an effective mathematical model, a parameterizer, and an optimum search algorithm). The use of the method makes it possible to improve or provide the necessary values of the main gas-dynamic parameters of the compressor by changing the shape of the blades and their relative position. The method was tested in solving optimization problems for multistage axial compressors of gas turbine engines (the number of stages from 3 to 15). As a result, an increase in efficiency, pressure ratio, and stability margins was achieved. The presented work is a summary of a long-years investigation of the research team and aims at creating a complete picture of the obtained results for the reader. A brief description of the results of industrial compresses optimization contained in the paper is given as an illustration of the effectiveness of the developed methods.

Supercritical Carbon Dioxide Centripetal Compressor—Aerodynamic Design and Analysis of Off Design Conditions

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
Xuefei Du ◽  
Dengtao Yu ◽  
Dan Luo ◽  
Diangui Huang
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Thermal Design ◽  
Test Method ◽  
Characteristic Line ◽  
Supercritical Carbon

Abstract Based on the design of the supercritical carbon dioxide (SCO2) centripetal compressor, this paper adopts the orthogonal design test method to optimize the pear-shaped volute, designs the front guide vane with the third-order Bezier curve, and designs the outlet by the equal section method. The numerical simulation calculation and analysis of the design conditions and variable conditions of the SCO2 centripetal compressor are carried out. The results at design conditions show that the isentropic efficiency is 92%, the pressure ratio is 1.21, and the mass flow rate is 195.9 kg/s, which is close to the thermal design and level simulation results; the results of variable conditions show that the efficiency of the SCO2 centripetal compressor-flow and pressure ratio-flow characteristic line is similar to that of multistage axial flow compressor. The supercritical carbon dioxide centripetal compressor designed in this paper meets the design requirements, and its feasibility is proved through numerical simulation.

Blade Shape Optimization of Transonic Axial Flow Fan in Terms of Sectional Profiles and Stacking Line

2014 ◽  
Author(s):  
Peng Song ◽  
Jinju Sun ◽  
Ke Wang
Keyword(s):  
Surrogate Model ◽  
Optimization Problem ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Optimization Method ◽  
Global Optimization Method ◽  
Blade Shape ◽  
Blade Tip ◽  
Overall Efficiency ◽  
Performance Gains

Transonic axial flow fan has relatively high blade tip speed and produces higher pressure ratio than the subsonic. However, considerable losses are brought about by the shock waves close to blade tip and over part of span, leading to deteriorated overall efficiency and operating flow range. It is generally acknowledged that modifications of blade stacking line (axially sweep and tangentially lean) and sectional profiles can help to control spanwise distribution of blade loading, reduce shock loss and secondary flow, and extend the operating flow range. The present study is to maximize the comprehensive benefits of simultaneously optimizing the sectional profiles and stack line by means of a global optimization method with reduced cost. In contrast with previous studies, it is of two distinguished features. First, in blade geometry parameterization, both sectional profiles and stacking line are varied to provide more flexible blade shape variation and subsequently permit more optimization performance gains. Secondly, with simultaneous variation of sectional profiles and stacking line, number of optimization variables and nonlinearity of optimization problem will increase largely. How to obtain a global optimal solution and also reduce the computation become the major concerns. For this purpose, a global optimization method proposed by us is used. It includes an improved CCEA (Cooperative Co-Evolution Algorithm) optimizer, adaptively updated kriging surrogate model, and one-stage Expected Improvement (EI) approach that permits adaptive sampling. At initial stage, a coarse surrogate model is constructed with small number of samples. During the optimization process, some new samples are identified, evaluated, and then used to refine the model and conduct further optimal searching. In the optimization process, the accuracy of the surrogate model is improved based on its own characteristics of optimization problem and this permits the optimizer to conduct the aim-oriented optimal searches. In such a manner, the surrogate model sustains high-level of accuracy while uses fewer samples, thus the blade optimization and computations are significantly reduced. The optimization is conducted for NASA Rotor67 at design flow rate with a single workstation of DELL 7500. It is demonstrated that the optimized blade design produces significant performance gains at design condition (where the overall efficiency and pressure ratio are increased respectively by 1.27 and 6.53 points) and also at off-design conditions.

Numerical Study on Duct Acoustic Modal and Source Flow Structure of Fan Tones With Leaned and Swept Stator

2020 ◽  
Author(s):  
Wang Liangfeng ◽  
Mao Luqin ◽  
Xiang Kangshen ◽  
Duan Wenhua ◽  
Tong Hang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Noise Reduction ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Sweep Angle ◽  
Lean Angle ◽  
Stator Blade ◽  
Angle Blade ◽  
Simulation Results

Abstract The present study is focused on the fan tone noise reduction with leaned and swept stator blade. A hybrid URANS/Goldstein’s equations method is used to calculate the unsteady flow and tone noise of a high loaded axial-flow fan. The numerical simulation results show that the fan tone noise will be increased with negative angle lean, while it will be reduced with positive lean angle. The higher the harmonic number, the larger the noise reduction with positive lean angle blade. It is found that when the stator blade sweeps back of 30 degrees, the fan tone noise at the fan inlet can be reduced by 5.5 dB, while the fan tone noise at the fan outlet can be reduced by 9.8dB. It is also found that the combined leaned and swept blade has the largest noise reduction. When the fan stator blade lean angle and sweep angle are both 30 degrees, the fan inlet tone noise can be reduced by 8.5 dB, while the fan outlet tone noise can be reduced by 17dB. The numerical simulation results indicate that the influence of blade lean and sweep on fan mass flow is less than 1% within the scope of this study. The negative lean angle of stator blade can improve the aerodynamic performance, but the positive lean angle of the stator blade will reduce the total pressure ratio and isentropic efficiency of the fan.

Design Optimization of Axial-Flow Pump Blades Based on iSIGHT

2015 ◽  
Author(s):  
Lijian Shi ◽  
Fangping Tang ◽  
Rongsheng Xie ◽  
Lilong Qi ◽  
Zhengdong Yang
Keyword(s):  
Numerical Simulation ◽  
Numerical Optimization ◽  
Optimization Design ◽  
Axial Flow ◽  
Optimization Method ◽  
Simulation Software ◽  
Multidisciplinary Optimization ◽  
Design Parameters ◽  
Axial Flow Pump ◽  
Flow Pump

This paper research the influence of cascade dense degree and airfoil placed angle on hydralic performance of axial flow pump blades. Which combines the numerical optimization technology with the advanced CFD simulation technique, replaces designers’ experience by mathematical models for controlling of the blade design direction. Finally, a platform for of the optimization design of axial-flow pump blades is built in this paper. The platform which based on the multidisciplinary optimization software iSIGHT is to design and optimize the axial flow blades. The automatic optimization design platform for axial-flow blade was established, in which the parameterization modeling, mesh, flow computation and numerical optimization are combined together. The use of the numerical simulation software CFD for disciplinary analysis improved the reliability and accuracy of the results of the prediction model. Found the approximate geometric design parameters of the design conditions based on numerical simulation, and the technology of numerical optimization was used for constrained optimized analysis based on these parameters. Optimized impeller efficiency improved about 0.7% while satisfying the constraint condition, shows that the optimization method for axial flow blade base on iSIGHT platform is effective and feasible. Meanwhile, the optimization method can greatly shorten the design cycle, reduce design cost optimization.

Aerodynamic Design of a Highly Loaded Axial Flow Fan Rotor Using a Novel One-Dimensional Design Method With its Numerical Simulation

2016 ◽  
Author(s):  
Ali Shahsavari ◽  
Mahdi Nili-Ahamadabadi
Keyword(s):  
Numerical Simulation ◽  
Design Method ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Flow ◽  
Numerical Results ◽  
Meridional Plane ◽  
Performance Curve ◽  
One Dimensional ◽  
Bypass Ratio

This paper presents a novel one-dimensional design method based on the radial equilibrium theory and constant span-wise diffusion factor to redesign of NASA rotor 67 just aerodynamically with a higher pressure ratio at the same design point. A one-dimensional design code is developed to obtain the meridional plane and blade to blade geometry of rotor to reach the three-dimensional view of rotor blades. To verify the redesigned rotor, its flow numerical simulation is carried out to compute its performance curve. The experimental performance curve of NASA rotor 67 is used for validation of the numerical results. Structured mesh with finer grids near walls is used to capture flow field and boundary layer effects. RANS equations are solved by finite volume method for rotating zones and stationary zones. The numerical results of the new rotor show about 9% increase in its pressure ratio at both design and off design mass flow rate. The new rotor has a higher outlet velocity through its upper span improving bypass ratio of a turbofan engine. To prove the new fan ability of producing more bypass ratio, a thermodynamic analysis is conducted. The results of this analysis show 13% increase in bypass ratio and 5.7% decline in specific fuel consumption in comparison to NASA rotor 67.

A High-Loaded Supersonic Axial Compressor Aerodynamic Design Principle

2012 ◽  
Author(s):  
Yingjiao Hu ◽  
Songtao Wang
Keyword(s):  
Numerical Simulation ◽  
Design Principle ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Axial Compressor ◽  
Axial Flow ◽  
Internal Flow ◽  
Aerodynamic Design ◽  
Simulation Results

Reviewed the historical development of the supersonic axial flow compressor, and gave an outlook for its future developments and research orientations. According to the internal flow characteristics of the conventional supersonic axial flow compressors, put forward a high load of supersonic axial compressor aerodynamic design principle. A preliminary design verification of the principle has been carried. The 3D viscous numerical simulation results show that, under the tip tangential speed 360m / s, has achieved a stage pressure ratio 2.3 with efficiency 86.5%. In addition, considering the rotor under impulse condition can get the maximum rotor total pressure ratio with high efficiency, a design principle has also been put forward to solve the high entrance Mach number problem of the downstream stator. But the numerical simulation results show that the multi-shock structure does not have any advantages to reduce the stator losses.

scholarly journals Design Optimization of a Multistage Axial Flow Compressor Based on Full-Blade Surface Parameterization and Phased Strategy

2021 ◽  
Vol 2021 ◽  
pp. 1-25
Author(s):  
Jinxin Cheng ◽  
Shengfeng Zhao ◽  
Zhaohui Dong ◽  
Chengwu Yang
Keyword(s):  
Design Optimization ◽  
Pressure Ratio ◽  
Parametric Method ◽  
Axial Flow ◽  
Optimization Method ◽  
Blade Surface ◽  
Exploration And Exploitation ◽  
Aerodynamic Optimization ◽  
Axial Flow Compressor ◽  
Flow Compressor

A new design optimization method is proposed for the problem of high-precision aerodynamic design of multistage axial compressors. The method mainly contains three aspects: full-blade surface parametrization can significantly reduce the number of control variables per blade row and increase the degrees of freedom of the leading edge blade angle compared with the traditional semiblade parametric method; secondly, the artificial bee colony algorithm improved initialization and food source exploration and exploitation mechanism to enhance the global optimization ability and convergence speed, and a distributed optimization system is built on the supercomputing platform based on this method; finally, a phased optimization strategy based on the “synchronous change in multirow blades” is proposed, and expert experience is introduced to achieve a better balance between exploration and exploitation. The optimization method is applied to the AL-31F four-stage low-pressure compressor. As a result, the adiabatic efficiency is improved by 0.67% and the surge margin is improved by 3.1% under the premise that the total pressure ratio and mass flow rate satisfy the constraints, which verifies the effectiveness and engineering practicality of the proposed optimization method in the field of multistage axial flow compressor aerodynamic optimization.

scholarly journals Axial Flow Compressor Stability Enhancement: Circumferential T-Shape Grooves Performance Investigation

Aerospace ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 12
Author(s):  
Marco Porro ◽  
Richard Jefferson-Loveday ◽  
Ernesto Benini
Keyword(s):  
Vortex Breakdown ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Suction Side ◽  
Treatment Technique ◽  
Tip Leakage Flow ◽  
Stall Inception ◽  
Stall Margin ◽  
Casing Treatment ◽  
Stall Margin Improvement

This work focuses its attention on possibilities to enhance the stability of an axial compressor using a casing treatment technique. Circumferential grooves machined into the case are considered and their performances evaluated using three-dimensional steady state computational simulations. The effects of rectangular and new T-shape grooves on NASA Rotor 37 performances are investigated, resolving in detail the flow field near the blade tip in order to understand the stall inception delay mechanism produced by the casing treatment. First, a validation of the computational model was carried out analysing a smooth wall case without grooves. The comparisons of the total pressure ratio, total temperature ratio and adiabatic efficiency profiles with experimental data highlighted the accuracy and validity of the model. Then, the results for a rectangular groove chosen as the baseline case demonstrated that the groove interacts with the tip leakage flow, weakening the vortex breakdown and reducing the separation at the blade suction side. These effects delay stall inception, improving compressor stability. New T-shape grooves were designed keeping the volume as a constant parameter and their performances were evaluated in terms of stall margin improvement and efficiency variation. All the configurations showed a common efficiency loss near the peak condition and some of them revealed a stall margin improvement with respect to the baseline. Due to their reduced depth, these new configurations are interesting because they enable the use of a thinner light-weight compressor case as is desirable in aerospace applications.

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