Optimization strategy for performance improvement of a lift fan cowl lip based on panel method

Author(s):  
Haitong Wang ◽  
Yangang Wang ◽  
Siwei Wang ◽  
Fang Zhou
Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 175
Author(s):  
Haoran Liu ◽  
Yeming Lu ◽  
Jinguang Yang ◽  
Xiaofang Wang ◽  
Jinjun Ju ◽  
...  

New, innovative optimization approaches to improve turbomachine performance and reduce turbomachine noise are significant in engineering. In this paper, based on the bionic concept, a wave structure is used to shape the leading edge of the blade. Using an NACA0018 blade as the basic blade, a united parametric approach controlled by three parameters is proposed to configure the wavy leading edge. Then, a new optimization strategy boosting design efficiency is established to output the optimal design results. Finally, the corresponding performance and flow mechanism are analyzed. Taking into account the existence of the hub wall and the shroud wall from the closed impeller, a near-wall adjustment factor is added, the significance of which is herein demonstrated. An optimal bionic blade is successfully obtained by the optimization strategy, which can reduce the mean drag coefficient by about 6% and the overall sound pressure level by about 3 dB, in relative to the original blade. Mechanism analysis revealed that the wave structure can induce spanwise velocity at the leading edge and cause a further delay in flow separation in the downstream region, synchronously reducing drag and noise.


2020 ◽  
Vol 10 (12) ◽  
pp. 4352
Author(s):  
Shijie Wang ◽  
Zhidan Weng ◽  
Bo Jin

This study presents a simulation model, optimization strategy and the experimental validation of a solenoid electromagnetic actuator that is widely used in industry components, especially in pneumatic/hydraulic valves. In the preliminary design, a two-dimensional magnetostatic finite element analysis (FEA) model is proposed and verified by static push-force comparisons between the two-dimensional FEA model, the three-dimensional FEA model and the experimental results. Then, a static and dynamic performance improvement strategy is proposed. To optimize the static push-force of the actuator, a static multi-objective optimization strategy for actuator structure parameters was developed based on a genetic algorithm. An experimental analysis of dynamic performance was carried out to improve the dynamic response of the actuator. By using a high-precision measuring device in the static-push-force test and dynamic direct current-input-signal tests, the comparisons results between the manufactured conventional actuator and the manufactured optimal actuators showed that the proposed optimization strategy was feasible. Through the static optimization strategy, the average static push-force in the working stroke was improved by 21.8%. Moreover, through the dynamic optimization strategy, the cutoff frequency of the push force response was improved by 129.1%, 79.6% and 74.3%, respectively, at three key positions in the working stroke.


2020 ◽  
pp. 1-11
Author(s):  
Wenjuan Ma ◽  
Xuesi Zhao ◽  
Yuxiu Guo

The application of artificial intelligence and machine learning algorithms in education reform is an inevitable trend of teaching development. In order to improve the teaching intelligence, this paper builds an auxiliary teaching system based on computer artificial intelligence and neural network based on the traditional teaching model. Moreover, in this paper, the optimization strategy is adopted in the TLBO algorithm to reduce the running time of the algorithm, and the extracurricular learning mechanism is introduced to increase the adjustable parameters, which is conducive to the algorithm jumping out of the local optimum. In addition, in this paper, the crowding factor in the fish school algorithm is used to define the degree or restraint of teachers’ control over students. At the same time, students in the crowded range gather near the teacher, and some students who are difficult to restrain perform the following behavior to follow the top students. Finally, this study builds a model based on actual needs, and designs a control experiment to verify the system performance. The results show that the system constructed in this paper has good performance and can provide a theoretical reference for related research.


2020 ◽  
Vol 1 (3) ◽  
pp. 316-324
Author(s):  
Syukrani Kadir

periodically in preparing learning plans, implementing learning, assessing learning achievement, carrying out follow-up assessments of student learning achievement that can improve teacher performance. This performance improvement is through periodic collaborative educational supervision. Based on the results of educational supervision in cycle I and cycle II, teacher performance increased, namely in cycle I, teacher performance in preparing learning plans in cycle I reached 71.98%, while cycle II was 92.44%. Teacher performance in implementing learning cycle I reached 72.44% while cycle II reached 93.81%. Teacher performance in assessing learning achievement in cycle Im reached 81.30% while cycle II was 90.56%. Teacher performance in carrying out follow-up assessments of student learning achievement in the first cycle reached 59.76% while the second cycle was 83.00%. Thus, the average action cycle II was above 75.00%. Based on the results of this study, it can be concluded that the teacher's performance has increased in preparing learning plans, implementing learning, assessing learning achievement, carrying out follow-up assessments of student learning achievement.


2020 ◽  
Vol 33 (109) ◽  
pp. 21-31
Author(s):  
І. Ya. Zeleneva ◽  
Т. V. Golub ◽  
T. S. Diachuk ◽  
А. Ye. Didenko

The purpose of these studies is to develop an effective structure and internal functional blocks of a digital computing device – an adder, that performs addition and subtraction operations on floating- point numbers presented in IEEE Std 754TM-2008 format. To improve the characteristics of the adder, the circuit uses conveying, that is, division into levels, each of which performs a specific action on numbers. This allows you to perform addition / subtraction operations on several numbers at the same time, which increas- es the performance of calculations, and also makes the adder suitable for use in modern synchronous cir- cuits. Each block of the conveyor structure of the adder on FPGA is synthesized as a separate project of a digital functional unit, and thus, the overall task is divided into separate subtasks, which facilitates experi- mental testing and phased debugging of the entire device. Experimental studies were performed using EDA Quartus II. The developed circuit was modeled on FPGAs of the Stratix III and Cyclone III family. An ana- logue of the developed circuit was a functionally similar device from Altera. A comparative analysis is made and reasoned conclusions are drawn that the performance improvement is achieved due to the conveyor structure of the adder. Implementation of arithmetic over the floating-point numbers on programmable logic integrated cir- cuits, in particular on FPGA, has such advantages as flexibility of use and low production costs, and also provides the opportunity to solve problems for which there are no ready-made solutions in the form of stand- ard devices presented on the market. The developed adder has a wide scope, since most modern computing devices need to process floating-point numbers. The proposed conveyor model of the adder is quite simple to implement on the FPGA and can be an alternative to using built-in multipliers and processor cores in cases where the complex functionality of these devices is redundant for a specific task.


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