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Effects of stability margin and thrust specific fuel consumption constrains on multi-disciplinary optimization for blended-wing-body design

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Chinese Journal of Aeronautics 2019年第8期32卷 1847-1859页

作者： Minghui ZHANG Zhenli CHEN Zhaoguang TAN Wenting GU Dong LI Changsheng YUAN Binqian ZHANG School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Shanghai Aircraft design and Research Institute Commercial Aircraft Corporation of ChinaLtd.Shanghai 200232China

Blended-Wing-Body(BWB) configuration, as an innovative transport concept, has become a worldwide research focus in the field of civil transports development. Relative to the conventional Tube-And-Wing(TAW) configuration, the BWB shows integrated benefits and serves as a most promising candidate for future ‘‘green aviation'. The objective of the present work is to figure out the effects of the stability margin and Thrust Specific Fuel Consumption(TSFC) on the BWB design in the framework of Multi-Disciplinary Optimization(MDO). A physically-based platform was promoted to study the effect static stability margin and engine technology level. Low-order physically based models are applied to the evaluation of the weight and the aerodynamic performance. The modules and methods are illustrated in detail, and the validation of the methods shows feasibility and confidence for the conceptual design of BWB aircrafts. In order to find out the relation between planform changes and the selection of stability and engine technology level, two sets of optimizations are conducted separately. The study proves that these two factors have dominant effects towards the optimized BWB designs in both aerodynamic shapes, weight distribution, which needs to be considered during the MDO design process. A balance diagram analysis is applied to find out a reasonable static stability margin range. It can be concluded that a recommended stability margin of a practical BWB commercial aircraft can be half of that of a conventional TAW design.

关键词： Aerodynamic design Blended-wing-body Multi-disciplinary optimization Optimization design Thrust specific fuel consumption

Aerodynamic design of three-stage vaneless counter-rotating turbine

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航空动力学报 2014年第7期29卷 1667-1679页

作者： ZHOU Kun LIU Huo-xing ZOU Zheng-ping WANG Lei National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Energy and Power Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China Turbine Division Shenyang Engine Design and Research Institute Aviation Industry Corporation of China Shenyang 110015 China

An aerodynamic design criterion was discussed for the 1+3/2 counter-rotating turbine by analyzing the velocity *** are 8 key aerodynamic parameters in the criterion,based on the consideration of aerodynamic efficiency and some strength ***,an aerodynamic design for the 1+3/2 counter-rotating turbine was made according to the criterion,and a three-dimensional simulation was conducted for ***,the conclusions were *** criterion containing 8 key aerodynamic parameters is verified rationally and the efficiency of the turbine reaches 91%.The aerodynamic characteristics of 1+3/2 counter-rotating turbine are mainly decided by the load coefficient,and due to an optimal power distribution coefficient of the low pressure turbine,the efficiency of the low pressure turbine can be best.

关键词： 1+3 2counter-rotating turbine velocity triangle aerodynamic design criterion three-dimensional simulation

Experimental Optimization of Jet Self-Priming Centrifugal Pump Based on Orthogonal design and Grey-Correlational Method

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Journal of Thermal Science 2020年第1期29卷 241-250页

作者： CHANG Hao SHI Weidong LI Wei WANG Chuan ZHOU Ling LIU Jianrui YANG Yongfei RAMESH KAgarwal Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China Department of Mechanical Engineering&Materials Science Washington University in St.LouisSt.Louis 63130USA School of Mechanical Engineering Nantong UniversityNantong 226019China School of Hydraulic Energy and Power Engineering Yangzhou UniversityYangzhou 225002China

The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so *** order to improve the profile streamline of blade,the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical,which can not only improve the pump efficiency,but also shorten the self-priming ***,the novel jet self-priming system was proposed,by employing the jet nozzle and check valve to improve the velocity of ***,nine different structure jet nozzles were designed based on the orthogonal design method,and the relevant self-priming experiments were performed on I level accuracy test bench in Jiangsu *** to the greycorrelational analysis,the influence of the nozzle geometry parameters on the self-priming performance was *** relationship between self-priming time and self-priming height was *** test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable;all indicators met the Chinese national standard;the head reached 21.04 m and efficiency was 72.8%under the design flow *** is more,the self-priming performance was obviously improved by adjusting the geometrical parameters of *** the height of the self-priming process was 5.3 m,the self-priming time reached 62 s,which was much shorter than the national ***,this research could provide reference for designing the structure of jet self-priming centrifugal pump.

关键词： self-priming centrifugal pump design optimization orthogonal experiment grey-correlational

Oxidative desulfurization of model and real oil samples using Mo supported on hierarchical alumina–silica: Process optimization by Box–Behnken experimental design

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Chinese Journal of Chemical Engineering 2019年第11期27卷 2759-2770页

作者： Nasim Ghorbani Gholamreza Moradi Catalyst Research Center Department of Chemical EngineeringFaculty of EngineeringRazi UniversityKermanshahIran

The catalytic performance of Mo supported on hierarchical alumina–silica(Si/Al = 15) with Mo loadings of 3, 6 and 15 wt% was investigated for the oxidative desulfurization(ODS) of model and real oil samples. Hierarchical alumina–silica(h Al–Si) was synthesized by economical and ecofriendly silicate-1 seed-induced route using cetyltrimethylammonium bromide(CTAB) as mesoporogen. The effect of CTAB on the structure of catalyst was studied by characterization techniques. The results revealed that 6%Mo/h Al–Si had the highest sulfur removal compared to the other catalyst loadings. The effect of operating parameters was evaluated using Box–Behnken experimental design. The optimal desulfurization conditions with the 6%Mo/h Al–Si catalyst were determined at oxidation temperature of 67 ℃, oxidation time of 42 min, H2O2/S molar ratio of 8 and catalyst dosage of 0.008 g·ml^-1 for achieving a conversion of 95%. Under optimal conditions, different sulfur-containing compounds with initial concentration of 1000 ppm, Dibenzothiophene(DBT), Benzothiophene(BT) and Thiophen(Th), showed the catalytic oxidation reactivity in the order of DBT > BT>Th. According to the regeneration experiments, the 6%Mo/h Al–Si catalyst was reused 4 times with a little reduction in the performance. Also, the total sulfur content of gasoline and diesel after ODS process reached 156.6 and 4592.2 ppm, respectively.

关键词： Oxidative desulfurization Hierarchical alumina–silica Silicate-1 seed-induced route Box–Behnken experimental design

Parameters optimization design of quenching and partitioning for best combination between strength and ductility using orthogonal experimental design

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Journal of Iron and Steel Research(International) 2019年第10期26卷 1088-1095页

作者： Ming-qing Liao Zhong-hong Lai Aorigele Bao Yong Liu Dan-ni Yang Tian-yi Han Jing-chuan Zhu Rong-da Zhao School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina The Center of Analysis Measurement Harbin Institute of TechnologyHarbin 150001HeilongjiangChina National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001HeilongjiangChina School of Materi

Quenching and partitioning(Q&P)which provides a balance between toughness and strength is a promising heat treatment in iron and steel ***,there are three parameters(quenching temperature,partitioning temperature and partitioning time)which affect the properties *** a result,it remains a challenge to get the best parameters in a low-cost way for Q&P ***,the orthogonal experimental design combined with a local optimization was adopted to optimize the quenching and partitioning parameters of 65Si2MnWA *** using this method,the combination between strength and ductility was optimized;meanwhile,the number of experiments was reduced *** treated by quenching at 180℃followed by partitioning at 330℃for 20 min,the steel reached the best combination between strength and *** detail,the product of ultimate tensile strength and reduction in area was 1.36 times(from 64.9 to 88.8 GPa%)that treated by quenching and *** addition,owing to the grain refinement,the strength and ductility increase ***,the reduction in area increased by 27.4%(from 35.8%to 45.6%)coupled with a little improvement in ultimate tensile strength(7.4%).

关键词： Parameter optimization design Quenching and partitioning Orthogonal experimental design Mechanical property 65Si2MnWA steel

Novel decoupled framework for reliability-based design optimization of structures using a robust shifting technique

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 800-820页

作者： Mohammad Reza GHASEMI Charles V. CAMP Babak DIZANGIAN Department of Civil Engineering University of Sistan and Baluchestan Zahedan *** Iran Department of Civil Engineering The University of Memphis Memphis TN 38152 USA Department of Civil Engineering Velayat University Iranshahr *** Iran

In a reliability-based design optimization (RBDO), computation of the failure probability (Pf) at all design points through the process may suitably be avoided at the early stages. Thus, to reduce extensive computations of RBDO, one could decouple the optimization and reliability analysis. The present work proposes a new methodology for such a decoupled approach that separates optimization and reliability analysis into two procedures which significantly improve the computational efficiency of the RBDO. This technique is based on the probabilistic sensitivity approach (PSA) on the shifted probability density function. Stochastic variables are separated into two groups of desired and non-desired variables. The three-phase procedure may be summarized as: Phase 1, apply deterministic design optimization based on mean values of random variables;Phase 2, move designs toward a reliable space using PSA and finding a primary reliable optimum point;Phase 3, applying an intelligent self-adaptive procedure based on cubic B-spline interpolation functions until the targeted failure probability is reached. An improved response surface method is used for computation of failure probability. The proposed RBDO approach could significantly reduce the number of analyses required to less than 10% of conventional methods. The computational efficacy of this approach is demonstrated by solving four benchmark truss design problems published in the structural optimization literature.

关键词： reliability-based design optimization trusses sensitivity analysis shifting technique cubic B-splines response surface method

Master equation,design equations and runaway speed of the Kaplan turbine

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Journal of Hydrodynamics 2021年第2期33卷 282-300页

作者： Zh.Zhang ZHAW Zurch University of Applied ScienceZurichSwitzerland

To make the Kaplan turbine technology comparable to both the Pelton and the Francis turbine,the master equation for the Kaplan turbine has been established by analyses similar to that-for the Francis *** analysis begins with the descriptions of free vortex flows at the runner inlet and the swirl flow at the impeller *** considering the Euler equation for specific work and by further evaluating the most significant shock and swirling losses,the first and the second energy equations in the form of hydraulic efficiency were *** master equation is then established by combining both energy *** addition,three design equations and a new design parameter are *** master equation relates the turbine hydromechanics to the geometrical design of both the runner and the guide-vane *** enables the complete hydraulic characteristics of a given Kaplan turbine to be analytically and simply computed.A computation example demonstrates the functionality and applicability of the *** the reconstructed master equation,the runaway speed of the Kaplan turbine and its dependence on the guide-vane setting can be easily and precisely *** bulb turbines with guide vanes directly ahead of the turbine runner in the same tube,all computations are also applicable using another equivalent control parameter.

关键词： Kaplan turbine master equation design equations design parameter runaway speed hydraulic efficiency shock loss swirling loss bulb turbines

Freeform imaging systems:Fermat's principle unlocks"first time right"design

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Light(Science & Applications) 2021年第6期10卷 1029-1040页

作者： Fabian Duerr Hugo Thienpont Brussels Photonics Department of Applied Physics and Photonics(B-PHOT TONA)Vrije Universiteit BrusselPleinlaan 21050 BrusselsBelgium

For more than 150 years,scientists have advanced aberration theory to describe,analyze and eliminate imperfections that disturb the imaging quality of optical components and ***,they have developed optical design methods for and manufacturing techniques of imaging systems with ever-increasing complexity and performanee up to the point where they are now including optical elements that are unrestricted in their surface *** so-called optical freeform elements offer degrees of freedom that can greatly extend the functionalities and further boost the specifications of state-of-the-art imaging ***,the drastically increased number of surface coefficients of these freeform surfaces poses severe challenges for the optical design process,such that the deployme nt of freeform optics remained limited until *** this paper,we present a deterministic direct optical design method for freeform imaging systems based on differential equations derived from Fermats principle and solved using power *** method allows calculating the optical surface coefficients that ensure minimal image blurring for each individual order of *** demonstrate the systematic,deterministic,scalable,and holistic character of our method with catoptric and catadioptric design *** such we introduce a disruptive methodology to design optical imaging systems from scratch,we largely reduce the "trial-and-error",approach in present-day optical design,and we pave the way to a fast-track uptake of freeform elements to create the nextgeneratio n high-end *** include a user application that allows users to experience this unique design method hands-on.

关键词： optics eliminate design

Coal pillar design when considered a reinforcement problem rather than a suspension problem

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International Journal of Mining Science and Technology 2018年第1期28卷 11-19页

作者： Russell Frith Guy Reed Mine Advice Pty Ltd New South Wales 2282Australia

Current coal pillar design is the epitome of suspension design.A defined weight of unstable overburden material is estimated, and the dimensions of the pillars left behind are based on holding up that material to a prescribed factor of *** principle, this is no different to early roadway roof support ***, for the most part, roadway roof stabilisation has progressed to reinforcement, whereby the roof strata is assisted in supporting *** is now the mainstay of efficient and effective underground coal *** and reinforcement are fundamentally different in roadway roof stabilisation and lead to substantially different requirements in terms of support hardware characteristics and their *** suspension, the primary focus is the total load-bearing capacity of the installed support and ensuring that it is securely anchored outside of the unstable roof *** contrast, reinforcement recognises that roof de-stabilisation is a gradational process with ever-increasing roof displacement magnitude leading to ever-reducing *** roof support characteristics relate to such issues as system stiffness, the location and pattern of support elements and mobilising a defined thickness of the immediate roof to create(or build) a stabilising strata *** objective is to ensure that horizontal stress is maintained at a level that prevents mass roof *** paper presents a prototype coal pillar and overburden system representation where reinforcement, rather than suspension, of the overburden is the stabilising mechanism via the action of in situ horizontal *** roadway roof reinforcement principles can potentially be applied to coal pillar design under this *** merit of this is evaluated according to failed pillar cases as found in a series of published *** on the findings, a series of coal pillar system design considerations for bord and pillar type mine workings are ***

关键词： Coal pillar design Overburden stability Rock reinforcement Bord and pillar mining