Wyniki wyszukiwania - BazTech

1

Structural optimization on the design of an automobile engine intake pipe

Xie Jianxin, Liu Zimeng

Journal of Theoretical and Applied Mechanics

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2022

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Vol. 60 nr 3

449--461

EN

The engine intake pipe is an important part of the engine. A reasonable layout of the intake pipe can prolong service life of the engine and improve engine power. The optimization of design of the intake pipe has a great impact on the overall performance of the engine. The design of the intake pipe based on experience is subjective and unilateral, and the design cycle and experimental period are long. Ansys Fluent software is used to simulate the design, which can more intuitively reflect the air flow condition of the intake pipe and enable selection of the best layout. First of all, a three-dimensional model of the intake pipe is simulated and the airflow characteristics are studied and analyzed. The streamline diagram and velocity contour under various conditions are obtained. Then, compared with the simulation results, the position of the intake pipe is optimized. Finally, the optimized intake pipe is simulated and verified. According to the experimental results, the intake performance of the optimized intake pipe is greatly improved.

2

Optimization design of multistage pump impeller based on response surface methodology

Peng Guangjie, Hong Shiming, Chang Hao, Zhang Zhuoran, Fan Fengyi

Journal of Theoretical and Applied Mechanics

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2021

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Vol. 59 nr 4

595--609

EN

The central composite design of the response surface methodology is applied to optimize ge- ometrical parameters of a multistage pump impeller in this paper, and a relevant experiment was conducted. The maximum head difference is 5.6%, and the maximum efficiency differ- ence is 0.73%, which can ensure the accuracy of the investigation. Meanwhile, 30 groups of test schemes are obtained based on the software Design Expert, and the numerical calcula- tion of each scheme is conducted. According to the calculation results and variance analysis, it is found that the effect of response variables of the primary terms blade number, impeller outlet diameter, blade outlet width, and the quadratic terms between the blade number and impeller outlet diameter, blade number and blade wrap angle, impeller outlet diameter and blade outlet width on the head are significant. However, the primary term blade wrap an- gle, the quadratic terms between the blade number and blade outlet width, impeller outlet diameter and blade wrap angle, blade wrap angle and blade outlet width have no significant effect on the head. Furthermore, a response surface regression model of the single-stage im- peller head of a multistage pump was established after removing insignificant factors, and the deviation of the response surface regression model is only 2.4%. The significant sequence of the influence of response variables on the head is the blade number, impeller diameter, blade outlet width, and blade wrap angle. Finally, the optimal geometrical parameters of the impeller are obtained: the number of blades is 6, the diameter of the impeller is 254 mm, the blade wrap angle is 119◦, the outlet width of the blade is 4.3 mm, and the predicted value of the head is 189.19 m. Therefore, the influence rule of impeller geometrical parameters on the head was obtained, which can provide theoretical references for the optimization design of the multistage pump impeller.

3

Research on a novel hybrid shielding structure of magnetic coupler for inductive power transfer system

Liu Yun Rui, Wang Chunfang, Xia Dongwei, Yue Rui

Archives of Electrical Engineering

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2021

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Vol. 70, nr 1

129--143

EN

With the development of wireless power transfer technology, more and more attention has been paid to its electromagnetic safety. In this paper, a novel hybrid shielding structure composed of the innermost fan-shaped ferrite, the interlayer nanocrystalline stripand the outermost aluminum foil is proposed to shield the electromagnetic field of the inductive power transfer system. Eight structure parameters of the proposed shielding areoptimized by finite element simulation, in order to reduce the magnetic leakage of the system and improve the utilization rate of shielding materials. In addition, the proposed structure is compared with two types of typical double-layer hybrid shielding from the perspectives of the weight, the coupling coefficient and the magnetic flux leakage. Both simulation and experiment results show that the cost and weight of the proposed shield are about 60% lower than the traditional disk shield. More over, the shielding layer proposed in this paper can not only effectively reduce the magnetic flux leakage of the system, but also maintain a high coupling coefficient.

4

Mechanical analysis and research of the conveyor belt of plane turning belt conveyor based on discrete element method

Li D. Y., Wang S., Hu K.

Archives of Transport

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2017

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Vol. 41, iss. 1

55--62

EN

In view of the size and the change of the load force of the conveyor belt at the turning point of the plane turning belt conveyor, the influencing factors of the stress of the conveyor belt at the turning point of the plane turning belt conveyor under full load condition are analyzed. A three dimensional model of the turning point of the plane turning belt conveyor is established. Combined with previous research experience, the formula for calculating the load is put forward. Based on discrete element method, multiple sets of internal curve elevation angle and the belt speed are used for dynamic simulation analysis. The results showed that the middle of conveyor belt is the most stressed, the lateral force second, the force of the inner conveyor belt is the least. Outside force increases with the increase of speed; there is no change in the middle band; the inner band force decreases with the increase of the velocity. Outside force decreases with the decrease of the inclination angle. With the change of the inclination angle, the force is basically unchanged. With the decreasing of the inclination angle, the force increases gradually. By optimizing the design parameters of the plane turning belt conveyor, the force of belt is reduced, and the service life of belt is improved.