The Biomimetic Shark Skin Optimization Design Method for Improving Lubrication Effect of Engineering Surface

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Yan Lu ◽  
Meng Hua ◽  
Zuomin Liu

Nature has long been an important source of inspiration for mankind to develop artificial ways to mimic the remarkable properties of biological systems. In this work, a new method was explored to fabricate a biomimetic engineering surface comprising both the shark-skin, the shark body denticle, and rib morphology. It can help reduce water resistance and the friction contact area as well as accommodate lubricant. The lubrication theory model was established to predict the effect of geometric parameters of a biomimetic surface on tribological performance. The model has been proved to be feasible to predict tribological performance by the experimental results. The model was then used to investigate the effect of the grid textured surface on frictional performance of different geometries. The investigation was aimed at providing a rule for deriving the design parameters of a biomimetic surface with good lubrication characteristics. Results suggest that: (i) the increase in depression width ratio Λ decreases its corresponding coefficient of friction, and (ii) the small coefficient of friction is achievable when Λ is beyond 0.45. Superposition of depth ratio Γ and angle's couple under the condition of Λ < 0.45 affects the value of friction coefficient. It shows the decrease in angle decreases with the increase in dimension depth Γ.

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.


2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983413
Author(s):  
Qisong Qi ◽  
Qing Dong ◽  
Yunsheng Xin

The nominal values of structural design parameters are usually calculated using a traditional deterministic optimization design method. However, owing to the failure of this type of method to consider potential variations in design parameters, the theoretical design results can be far from reality. To address this problem, the specular reflection algorithm, a recent advancement in intelligence optimization, is used in conjunction with a robust design method based on sensitivity. This method not only is able to fully consider the influence of parameter uncertainty on the design results but also has strong applicability. The effectiveness of the proposed method is verified by numerical examples, and the results show that the robust design method can significantly improve the reliability of the structure.


Author(s):  
Kyung-Nam Chung ◽  
Yang-Ik Kim ◽  
Ju-Heon Sung ◽  
In-Ho Chung ◽  
Sang-Hoon Shin

In this study, an optimization design method is established for a rotor blade of a Curtis turbine. Bezier curve is generally used to define the profile of turbine blades. However, this curve is not proper to a supersonic impulse turbine. Section shape of a supersonic turbine blade is composed of straight lines and circular arcs. That is, it has several constraints to define the section shape. Thus, in this study, a blade design method is developed by using B-spline curve in which local control is possible. The turbine blade section has been changed by varying three design parameters of exit blade angle, stagger angle and maximum camber. Then flow analyses have been carried out for the sections. Lift-drag ratio of the blade section is used as the object function, and it is maximized in the optimization. Second-order response surface model is employed to express the object function as a function of design parameters. Central composite design method is used to reduce the number of design points. Then, an evolution strategy is employed to obtain the optimized section of the Curtis turbine blade.


2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Wei Yang ◽  
Ruofu Xiao

This paper presents an automatic multiobjective hydrodynamic optimization strategy for pump–turbine impellers. In the strategy, the blade shape is parameterized based on the blade loading distribution using an inverse design method. An efficient response surface model relating the design parameters and the objective functions is obtained. Then, a multiobjective evolutionary algorithm is applied to the response surface functions to find a Pareto front for the final trade-off selection. The optimization strategy was used to redesign a scaled pump–turbine. Model tests were conducted to validate the final design and confirm the validity of the design strategy.


2021 ◽  
Vol 30 (1) ◽  
pp. 1040-1053
Author(s):  
Ying Xia ◽  
Mohammad Asif Ikbal ◽  
Mohd Asif Shah

Abstract The machines exhibit an intelligence which is artificial intelligence (AI), and it is the design of intelligent agents. A system is represented by an intelligent agent who perceives its environment and the success rate is maximized by taking the action. The AI research is highly specialized and there are two subfields and each communication fails often. The popular AI approaches include the traditional symbolic AI and computational intelligence. In order to optimize the seismic design of the reinforced concrete pier structure, the particle swarm optimization (PSO) algorithm and the reaction spectrum analysis method are combined; they establish a regular bridge of the design variable with cross-sectional characteristics and reinforcement ratios, with the target function. The seismic optimization design framework of the pier is transformed into a multi-objective optimization problem. Calculations show that the method can quickly obtain the optimal design parameters that meet multi-objective requirements. The improved PSO main program and the calling push-over program run time are 4.32 and 1347.56 s, respectively; the push-over program running time is 99.68% of the run time of the total program. Optimization of the seismic performance of the rear bridge pier is significantly improved and is more in line with the design method; the design method proposed in this article is more practical.


2010 ◽  
Vol 37-38 ◽  
pp. 501-504
Author(s):  
Zhen Guo Sun ◽  
Bo Qin Gu ◽  
Xing Lu Huang

Based on the time-correlated leakage model and fuzzy random probability theory, a formula for calculating fuzzy random reliability of sealing performance of bolted flanged connections was derived. The optimization variables were defined according to the sensitivity analysis of design parameters on fuzzy reliability of sealing performance. A fuzzy reliability optimization design method of flange was investigated, in which both the tightness of bolted flanged connections and the strength of flange were taken into consideration. As an example, an integral welding necked pipe flange was designed according to the optimization design method proposed in this paper. The designed flange not only satisfies the requirements of flange strength and sealing reliability of connections, but also its weight is reduced by 16% compared with that prescribed in the standard.


2014 ◽  
Vol 1030-1032 ◽  
pp. 851-854
Author(s):  
Yong Chun Cheng ◽  
Ji Zhong Zhao ◽  
Peng Zhang ◽  
Jing Lin Tao ◽  
Ya Feng Gong

This paper improves the method of calculating the vertical bearing capacity of bored piles, and unifies calculation method of singe pile under horizontal force, as well adds and modifies the design parameters of the specification, finally utilizes actual example to make a unified test of the above methods. The results proved that, through the optimization of bridge foundation design method of bored piles, it can significantly reduce construction cost, and makes the pile length, pile diameter, and reinforcement more safe and reasonable. At the same time, it has great directive significance to the design and construction of the bridge.


2014 ◽  
Vol 997 ◽  
pp. 69-72
Author(s):  
Xian Jun Meng ◽  
Tie Xin Hou ◽  
Hai Qing Cui

Aiming at the design goal of the highest efficiency of the electric submersible pump of polymer flooding and basing on the coordination of the production system of the electric submersible pump well of polymer flooding and taking oil well productivity and parameters of electric submersible pump (displacement, lift, power) of the electric submersible pump as the design parameters, a mathematical model of the optimization design method for the production parameters of the electric submersible pump well of polymer flooding using the nodal system analysis method was established, and through the mathematical model mentioned above, the optimization design method for the production parameters of the electric submersible pump well of polymer flooding was given. The optimization design method mentioned above, taking the electric submersible pump well B1-D4-71 of Daqing Oilfield as an example, was applied. The results indicate that the method mentioned above can make the electric submersible pump work in the high efficiency area after the electric submersible pump well B1-D4-71’s being put into production.


2011 ◽  
Vol 84-85 ◽  
pp. 3-7
Author(s):  
Meng Sheng Wang ◽  
Rui Ping Zhou ◽  
Xiang Xu

Multidisciplinary Design Optimization (MDO) is a new method for achieving an overall optimum design of the complex system. In this paper have researched how to make the mathematical model of the diesel engine system in the CO (Coordination Design Optimization) method, and applied it in the actual practice. The application result demonstrates that in this optimization method, we can achieve the optimal design of this diesel engine by the coordination of rationally configuring the design parameters, and improve the economy, the technical performance, the reliability and the service life of the designed engine.


2011 ◽  
Vol 65 ◽  
pp. 281-284 ◽  
Author(s):  
Cai Li Zhang ◽  
Fan Yang

According to pressure vessel material waste problem in the traditional design, the finite element technique is used to pressure vessel optimization design in this paper. Firstly, the finite element analysis is applied to carry out stress calculation, and we extracted the related results parameters for following calculation. Then we conducted the quantitative calculation after choosing optimization design method, and got the best design parameters which meet performance indexes. At last, we conducted the optimization design of pressure vessels using this technology. Practical results prove the validity and the practicability of this method in the pressure vessels design.


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