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Fluid Dynamics & Materials Processing 2024年第6期20卷 1279-1297页

作者： Yasser Jebbar Fadhil Fluiful Wisam Khudhayer department of Electrical Techniques Al-Mussaib Technical InstituteAl-Furat Al-Awsat Technical UniversityBabilIraq department of Physics Collage of ScienceUniversity of KerbalaKarbalaIraq department of Energy engineering Collage of Engineering/Al-MusayabUniversity of BabylonBabilIraq

This study includes an experimental and numerical analysis of the performances of a parabolic trough collector(PTC)with and without cylindrical *** PTC is designed with dimensions of 2.00 m in length and 1.00 m in *** related reflector is made of lined sheets of aluminum,and the tubes are made of stainless steel used for the absorption of *** have an outer diameter of 0.051 m and a wall thickness of 0.002 ***,used as a heat transfer fluid(HTF),flows through the absorber tube at a mass flow rate of 0.7 kg/*** dimensions of cylindrical turbulators are 0.04 m in length and 0.047 m in *** are performed using the ANSYS Fluent 2020 R2 *** PTC performance is evaluated by comparing the experimental and numerical outcomes,namely,the outlet temperature,useful heat,and thermal efficiency for a modified tube(MT)(tube with novel cylindrical turbulators)and a plain tube(PT)(tube without novel cylindrical turbulators).According to the results,the experimental outlet temperatures recorded 63.2°C and 50.5°C for the MT and PT,*** heat gain reaches 1137.5 Win the MT and 685.8 Win the *** to the PT collector,the PTC exhibited a(1.64 times)higher efficiency.

关键词： Parabolic trough collector turbulators absorber tube ANSYS thermal efficiency

Theoretical investigation on axial cyclic performance of monopile in sands using interface constitutive models

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Journal of Rock Mechanics and Geotechnical engineering 2024年第7期16卷 2645-2662页

作者： Pan Zhou Jingpei Li Kaoshan Dai Stefan Vogt Seyedmohsen Miraei department of Geotechnical engineering Tongji UniversityShanghai200092China department of Civil Geo and Environmental EngineeringTechnical University of MunichFranz-Langinger-Str.10München81245Germany department of Civil engineering Sichuan UniversityChengdu610065China

Cyclic loads generated by environmental factors,such as winds,waves,and trains,will likely lead to performance degradation in pile foundations,resulting in issues like permanent displacement accumulation and bearing capacity *** paper presents a semi-analytical solution for predicting the axial cyclic behavior of piles in *** solution relies on two enhanced nonlinear load-transfer models considering stress-strain hysteresis and cyclic degradation in the pile-soil *** parameters are calibrated through cyclic shear tests of the sand-steel interface and laboratory geotechnical testing of sands.A novel aspect involves the meticulous formulation of the shaft loadtransfer function using an interface constitutive model,which inherently inherits the interface model’s advantages,such as capturing hysteresis,hardening,degradation,and particle *** semi-analytical solution is computed numerically using the matrix displacement method,and the calculated values are validated through model tests performed on non-displacement and displacement piles in *** results demonstrate that the predicted values show excellent agreement with the measured values for both the static and cyclic responses of piles in *** displacement pile response,including factors such as bearing capacity,mobilized shaft resistance,and convergence rate of permanent settlement,exhibit improvements compared to non-displacement piles attributed to the soil squeezing *** methodology presents an innovative analytical framework,allowing for integrating cyclic interface models into the theoretical investigation of pile responses.

关键词： Piles Cyclic degradation Load-transfer models Interface constitutive model Semi-analytical solution Model tests

Dynamic response of honeycomb-FGS shells subjected to the dynamic loading using non-polynomial higher-order IGA

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Defence Technology（防务技术） 2024年第7期37卷 149-161页

作者： Pham Binh Le Trung-Thanh Tran Faculty of Mechanical engineering Le Quy Don Technical UniversityHanoiViet Nam

The main goal of this study is to use higher-order isogeometric analysis(IGA)to study the dynamic response of sandwich shells with an auxetic honeycomb core and two different functionally graded materials(FGM)skin layers(namely honeycomb-FGS shells)subjected to dynamic ***'s non-polynomial higher-order shear deformation theory(HSDT)is used due to its simplicity and *** governing equation is derived from Hamilton's *** verifying the present approach,the effect of input parameters on the dynamic response of honeycomb-FGS shells is carried out in detail.

关键词： IGA Elastic foundation Dynamic response FGM Auxetic honeycomb Shell

Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology

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China Foundry 2024年第1期21卷 60-70页

作者： İsmail Cem Akgün Çağın Bolat Ali Gökşenli Faculty of Mechanical engineering Istanbul Technical University34437İstanbulTurkey Faculty of engineering Samsun University55420SamsunTurkey

In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and *** this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a *** to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors *** this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF ***,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive *** results show that PEC particles can be an alternative to expensive hollow spheres used in the previous ***,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength.

关键词： die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation

Exciton-polaritons in a 2D hybrid organic-inorganic perovskite microcavity with the presence of optical Stark effect

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Chinese Physics B 2024年第3期33卷 551-555页

作者： Kenneth Coker 郑楚媛 Joseph Roger Arhin Kwame Opuni-Boachie Obour Agyekum 张伟利 School of Information and Communication engineering University of Electronic Science and Technology of ChinaChengdu 611731China department of Electrical and Electronic engineering Ho Technical UniversityHo 00233Ghana Telecommunication engineering department Kwame Nkrumah University of Science and TechnologyKumasi 00233Ghana

This study investigates the properties of exciton-polaritons in a two-dimensional(2D)hybrid organic-inorganic perovskite microcavity in the presence of optical Stark *** both steady and dynamic state analyses,strong coupling between excitons of perovskite and cavity photons is revealed,indicating the formation of polaritons in the perovskite ***,it is found that an external optical Stark pulse can induce energy shifts of excitons proportional to the pulse intensity,which modifies the dispersion characteristics of the polaritons.

关键词： exciton-polaritons perovskite microcavity optical Stark effect

Falcon Optimization Algorithm-Based Energy Efficient Communication Protocol for Cluster-Based Vehicular Networks

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Computers, Materials & Continua 2024年第3期78卷 4243-4262页

作者： Youseef Alotaibi B.Rajasekar R.Jayalakshmi Surendran Rajendran department of Software engineering College of ComputingUmm Al-Qura UniversityMakkah21955Saudi Arabia department of Electronics and Communication engineering Sathyabama Institute of Science and TechnologyChennai600119India department of Computer Science and engineering Panimalar Engineering CollegeChennai600123India department of Computer Science and engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical ScienceChennai602105India

Rapid development in Information Technology(IT)has allowed several novel application regions like large outdoor vehicular networks for Vehicle-to-Vehicle(V2V)*** networks give a safe and more effective driving experience by presenting time-sensitive and location-aware *** communication occurs directly between V2V and Base Station(BS)units such as the Road Side Unit(RSU),named as a Vehicle to Infrastructure(V2I).However,the frequent topology alterations in VANETs generate several problems with data transmission as the vehicle velocity differs with ***,the scheme of an effectual routing protocol for reliable and stable communications is *** research demonstrates that clustering is an intelligent method for effectual routing in a mobile ***,this article presents a Falcon Optimization Algorithm-based Energy Efficient Communication Protocol for Cluster-based Routing(FOA-EECPCR)technique in *** FOA-EECPCR technique intends to group the vehicles and determine the shortest route in the *** accomplish this,the FOA-EECPCR technique initially clusters the vehicles using FOA with fitness functions comprising energy,distance,and trust *** the routing process,the Sparrow Search Algorithm(SSA)is derived with a fitness function that encompasses two variables,namely,energy and distance.A series of experiments have been conducted to exhibit the enhanced performance of the FOA-EECPCR *** experimental outcomes demonstrate the enhanced performance of the FOA-EECPCR approach over other current methods.

关键词： Vehicular networks communication protocol clustering falcon optimization algorithm routing

Passive particles driven by self-propelled particle:The wake effect

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Chinese Physics B 2024年第4期33卷 500-507页

作者：郑凯选汪静文王世锋聂德明 Institute of Fluid Mechanics China Jiliang UniversityHangzhou 310018China department of Mechanical engineering Hangzhou Vocational&Technical CollegeHangzhou 310018China

This work focuses on numerically studying hydrodynamic interaction between a passive particle and a self-propelled particle,termed a squirmer,by using a two-dimensional lattice Boltzmann method(LBM).It is found that the squirmer can capture a passive particle and propel it simultaneously,provided the passive particle is situated within the squirmer's *** research shows that the critical capture distance,which determines whether the particle is captured,primarily depends on the intensity of the squirmer's *** stronger dipolarity of squirmer results in an increased critical capture ***,the Reynolds number is found to have minimal influence on this ***,the passive particle,when driven by the squirmer's wake,contributes to a reduction in the squirmer's *** results in a mutual acceleration for both *** findings can provide valuable perspectives for formulating the principles of reducing the drag of micro-swimmers and help to achieve the goal of using micro-swimmers to transport goods without physical tethers.

关键词： lattice Boltzmann method(LBM) self-propelled particles particle-laden flow

An Integral Method for Solving Dynamic Equations with Fluid–Solid Coupling

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Acta Mechanica Solida Sinica 2024年第1期37卷 99-108页

作者： Xin Zhang Jie Liu Pu Xue Shuowen Yan Yahao Xu M.S.Zahran School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China School of Mechatronical engineering Beijing Institute of TechnologyBeijing 100081China department of Civil engineering Military Technical CollegeCairo 11435Egypt

In this work,a new methodology is presented to mainly solve the fluid–solid interaction(FSI)*** methodology combines the advantages of the Newmark precise integral method(NPIM)and the dual neural network(DNN)*** NPIM is employed to modify the exponential matrix and loading vector based on the DNN integral *** involves incorporating the basic assumption of the Newmark-βmethod into the dynamic equation and eliminating the acceleration term from the dynamic equilibrium *** a result,the equation is reduced to a first-order linear equation ***,the PIM is applied to integrate the system step by step within the *** DNN method is adopted to solve the inhomogeneous term through fitting the integrand and the original function with a pair of neural networks,and the integral term is solved using the Newton–Leibniz *** examples demonstrate that the proposed methodology significantly improves computing efficiency and provides sufficient precision compared to the DNN *** is particularly evident when analyzing large-scale structures under blast loading conditions.

关键词： Newmark precise integral method(NPIM) Dual neural networks(DNN) Fluid-solid interaction(FSI) Dynamic time-history analysis Blast loading

Electrically tunable third-harmonic generation using intersubband polaritonic metasurfaces

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Light(Science & Applications) 2024年第8期13卷 1666-1674页

作者： Seongjin Park Jaeyeon Yu Gerhard Boehm Mikhail A.Belkin Jongwon Lee department of Electrical engineering Ulsan National Institute of Science and Technology(UNIST)UlsanRepublic of Korea Walter Schottky Institute Technical University of MunichGarchingGermany

Nonlinear intersubband polaritonic metasurfaces,which integrate giant nonlinear responses derived from intersubband transitions of multiple quantum wells(MQWs)with plasmonic nanoresonators,not only facilitate efficient frequency conversion at pump intensities on the order of few tens of kW cm^(-2)but also enable electrical modulation of nonlinear responses at the individual meta-atom level and dynamic beam *** electrical modulation characteristics of the magnitude and phase of the nonlinear optical response are realized through Stark tuning of the resonant intersubband *** this study,we report,for the first time,experimental implementations of electrical modulation characteristics of mid-infrared third-harmonic generation(THG)using an intersubband polaritonic metasurface based on MQW with electrically tunable third-order nonlinear ***,we achieved a 450%modulation depth of the THG signal,86%suppression of zero-order THG diffraction tuning based on local phase tuning exceeding 180 degrees,and THG beam steering using phase *** work proposes a new route for electrically tunable flat nonlinear optical elements with versatile functionalities.

关键词： tunable tuning pump

Study of relationship between motion of mechanisms in gas operated weapon and its shock absorber

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Defence Technology（防务技术） 2024年第3期33卷 42-54页

作者： Jiri Balla Roman Vitek Dung Nguyen Van Zbynek Krist Hung Nguyen Van department of Weapons and Ammunition University of Defence BrnoCzech Republic department of Weapons Le Quy Don Technical UniversityHanoiViet Nam department of Design and Special engineering Alexander Dubcek University of TrencinSlovakia

The article deals with the motion of the breech block carrier and the weapon casing of an automatic weapon mounted on a flexible carriage and the base of the *** works,which did not consider the dynamic properties of the base of the weapon,did not allow to reconcile the calculated and experimental results of the weapon casing displacement when shooting from firing *** the analysis of the motion of individual parts,the methods of mathematical modelling and firing experiments using a high-speed camera were *** show the best accord with experiment when modelling the system with 4 degrees of *** oscillation of the system regarding the movement of the breech block carrier and the weapon casing was investigated under changed conditions of rate of fire,the use of a muzzle brake and different types of shock *** velocities and displacements of the weapon casing and the breech block carrier at different values of the impulse of the gases to the breech block carrier were determined.

关键词： Shock absorber Gas-operated weapon Force-impulse diagram Recoil system Breech block carrier