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Particuology 2024年第7期90卷 364-382页

作者： Barış Gürel Gülşah Karaca Dolgun Osman ipek Ali Keçebaş department of mechanical engineering Engineering FacultySüleyman Demirel UniversityÇünürIspartaTurkey department of energy systems engineering Technology FacultyMuğla SıtkıKoçman UniversityKötekliMenteşeMuğlaTurkey

this study delves into the combustion behavior of various lignite types within a circulating fluidized bed boiler(CFBB),with a primary focus on the impact of different bed material sphericity ratios(0.5,0.7,and 0.9).Utilizing bed material with a sphericity ratio of 0.9 sourced from theÇan power plant and verified through experimentation,the research reveals several key ***,furnace temperatures tended to rise with higher sphericity ratios,albeit with variations between lignite types,particularly highlighting the complexity of this relationship in the case of GLi-tunçbilek *** levels in the combustion chamber remained consistent across different sphericity ratios,indicating minimal influence on pressure *** combustion efficiency,especially at the bottom of the boiler,was observed at lower sphericity levels(0.5 and 0.7)forÇan lignite,as reflected in CO_(2) mole *** NO_(x) emissions generally decreased with lower sphericity,the sensitivity to sphericity varied by lignite type,with ilgın lignite showcasing low NO_(x) but high sO_(2) emissions,underscoring the intricate interplay between lignite properties,sphericity,and ***,this study advances our understanding of CFBB combustion dynamics,offering insights valuable for optimizing performance and emissions control,particularly in lignite-based power.

关键词： Circulating fluidized bed boiler Computational particle fluid dynamics method Particle sphericity ratios NO_(x)and sO_(2)emissions energy production efficiency

Performance and combustion study of a low heat rejection engine running with biogas–diethyl ether–diesel

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Waste Disposal and sustainable energy 2024年第1期6卷 151-162页

作者： sanjaya K.Mishra Premananda Pradhan shakti P.Jena department of mechanical engineering S‘O’A Deemed to be UniversityBhubaneswar751030India

the present research focuses on addressing the faster depletion of fossil fuels and environmental pollution in addition to the energy crisis that hinders the progress of a *** the current research,waste banana leaves were considered as substrates for biogas *** is taken as the primary fuel in dual fuel(DF)operations to maximize possible diesel *** performance and combustion assessment were executed in a low heat rejection(LHR)engine using 5%diethyl ether by volume blended with diesel(5Dee)as pilot *** combustion attributes of the engine reveal that the apex of net heat release rate(NHRR)curve retarded a bit as compared to apex of base *** peak cylinder pressure was noted to be 6.19 MPa in the LHR engine running with 5Dee+biogas at 11.7°crank angle(CA)after top dead center(atDC)compared to 5.23 MPa for the diesel alone operation at the same *** apex point for NHRR was observed to be 54.51 J(°)^(−1)for 5Dee+biogas in LHR engine positioned at 3.2°*** brake thermal efficiency at full engine load operation decreased by 12.7%and 5.2%for biogas substitutions of 0.8 kg h^(−1)with diesel and 5Dee,respectively,compared to the base *** smoke opacity and nitric oxide emissions were reduced during the DF run accompanied by diethyl ether as a fuel additive.

关键词： Biogas Banana leaves Coating Diesel engine Diethyl ether exhaust emissions

Analysis and Optimization of Operational and Pollutant Attributes of Diesel engine with CNt-infused Orange Peel Biodiesel-Diesel Blend Fuel

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Journal of thermal science 2024年第2期33卷 761-778页

作者： Ranjeet RAi R.R.sAHOO mechanical engineering department GLA UniversityMathura281406India mechanical engineering department IIT(BHU)Varanasi221005India

the current study is performed to find sustainable solutions for the future of transportation and environmental *** conventional methods and experimental design table(L16 Orthogonal Array)techniques have been employed to examine and optimize a diesel-powered engine's operational and pollutant *** L16 Orthogonal Array is obtained through taguchi's experimental design approach using Minitab 16 *** experimental design incorporated three control variables,namely engine speed,fuel type,and engine load,each with four *** operational parameters,namely brake thermal efficiency(Bte)and brake specific fuel consumption(BsFC),as well as the emission characteristics,including hydrocarbon(HC),carbon monoxide(CO),nitrogen oxide(NO),and smoke emissions,were acquired using the L16 orthogonal array(OA) and subsequently *** utilization of methodologies such as signal-to-noise(s/N) ratio and grey analysis was employed to determine the optimal operational state of the engine to achieve maximum performance while minimizing *** engine's ideal state of operation,in terms of Bte and BsFC,was determined to be at 75% engine load,1000 r/min engine speed,and using 10^(-4)(in vol) carbon nanotube incorporated 20% orange peel biodiesel(OPB20CNt100) blended fuel(A3-B1-C4).the study indicated that engine load significantly influenced Bte and BsFC,with 84.05% and 87.79% contribution factors,*** 25% engine load,1000 r/min,and OPB20CNt100 fuel(A1-B1-C4) CO,smoke,NO,and HC emissions were the *** load affects emissions the *** BsFC increased 3.10% and NO emissions 1.77%.Bte,CO,smoke,and HC emissions decreased by 1.9%,12.29%,47.05%,and 47.22%,respectively,at optimal operating conditions concerning diesel *** study shows that taguchi-Grey's experimental design optimizes diesel engine operational and pollutant *** outcomes revealed that orange peel biodiesel infused with CNt can replace diesel fuel in a

关键词： taguchi-Grey method OPB20CNt100 transesterification s/N ratio GRG HC CO and NO

experimental and Finite element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite

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Computer Modeling in engineering & sciences 2024年第8期140卷 1783-1806页

作者： seyed Mohammad Reza Abtahi saeid Ansari sadrabadi Gholam Hosein Rahimi Gaurav singh Hamid Abyar Daniele Amato Luigi Federico Faculty of mechanical engineering Tarbiat Modares UniversityTehran***Iran A.Leon Linton department of mechanical Robotics and Industrial EngineeringLawrence Technological UniversitySouthfieldMI48075USA department of mechanical engineering Faculty of EngineeringMeybod UniversityYazd***Iran department of industrial engineering University of SalernoVia Giovanni PaoloⅡFiscianoItaly italian Aerospace Research Center(C.i.R.A.) Via MaioriseCapuaCE81043Italy

Repairs of corroded high-pressure pipelines are essential for fluids transportation under high *** of the methods used in their repairs is the use of layered *** composite used must have the necessary ***,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including AsMe PCC-2,AsMe B31.8s,AsMe B31.4,isO 24817 and AsMe *** addition,the experimental tests are replicated numerically using the finite element *** the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high *** direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the *** reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.

关键词： High-pressure pipeline composite repair AsMe PCC-2 isO 24817

Research progress in friction stir processing of magnesium alloys and their metal matrix surface composites: evolution in the 21^(st )century

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Journal of Magnesium and Alloys 2024年第6期12卷 2091-2146页

作者： Roshan Vijay Marode tamiru Alemu Lemma Nabihah sallih srinivasa Rao Pedapati Mokhtar Awang Adeel Hassan department of mechanical engineering Universiti Teknologi PETRONASBandarSeri IskandarPerak 32610Malaysia department of mechanical engineering College of EngineeringThe University of Texas Permian BasinMidland-OdessaUnited States mechanical engineering department Universiti Teknologi BruneiBrunei

Rising concerns about climate change drive the demand for lightweight ***(Mg)alloys are highly valued for their low weight,making them increasingly important in various *** focusing on enhancing the characteristics of Mg alloys and developing their Metal Matrix Composites(MMCs)have gained significant attention worldwide over the past decade,driven by the global shift towards lightweight *** stir Processing(FsP)has emerged as a promising technique to enhance the properties of Mg alloys and produce ***,FsP adapted to refine grain size from the micro to the nano level and accelerated the development of MMCs due to its solid-state nature and the synergistic effects of microstructure refinement and reinforcement,improving strength,hardness,ductility,wear resistance,corrosion resistance,and fatigue ***,producing defect-free and sound FsPed Mg and Mg-MMCs requires addressing several variables and their interdependencies,which opens up a broad range of practical *** existing reviews on individual FsP of Mg,its alloys,and MMCs,an attempt has been made to analyze the latest research on these three aspects collectively to enhance the understanding,application,and effectiveness of FsP for Mg and its *** review article discusses the literature,classifies the importance of Mg alloys,provides a historical background,and explores developments and potential applications of FsPed Mg *** focuses on novel fabrication methods,reinforcement strategies,machine and tool design parameters,material characterization,and integration with other methods for enhanced *** influence of process parameters and the emergence of defects are examined,along with specific applications in mono and hybrid composites and their microstructure *** study identifies promising reinforcement materials and highlights research gaps in FsP for Mg alloys and MMCs *** conclude

关键词： Magnesium alloys Friction stir processing Metal matrix composites Lightweight surface modification

Heat and mass transfer of a circular porous moist object located in a triangular shaped vented cavity

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Journal of Central south University 2024年第6期31卷 1956-1972页

作者： seLiMeFeNDiGiL Fatih OZCAN COBAN seda OZtOP Hakan F department of mechanical engineering College of EngineeringKing Faisal UniversityAl Ahsa 31982Saudi Arabia department of mechanical engineering Manisa Celal Bayar UniversityManisa 45140Turkey department of mechanical engineering Technology FacultyFırat UniversityElazığTurkey

Heat and mass transfer of a circular-shaped porous moist object inside a two-dimensional triangle cavity is investigated by using finite element *** porous object is considered to be a moist food sample,located in the middle of the cavity with inlet and outlet ports with different configurations of inlet/outlet *** drying performance is numerically assessed for different values of Reynolds numbers(between 50 and 250),dry air inlet temperature(between 40 and 80℃)and different locations of the *** is observed that changing the port locations has significant impacts on the flow recirculaitons inside the triangular chamber while convective drying performance is highly *** moisture content reduces with longer time and for higher Reynolds number(Re)*** P4 where inlet and outlet ports are in the middle of the walls provides the most effective configuration in terms of convective drying performance while the worst case is seen for P1 case where inlet and outlet are closer to the corners of the *** is a 192% difference between the moisture reduction of these two cases at Re=250,t=80℃ and t=120 min.

关键词： convective drying porous domain cavity flow inlet/exit port finite element method

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied Mathematics and Mechanics(english edition) 2024年第3期45卷 543-562页

作者： H.M.FeiZABAD M.H.YAs department of mechanical engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** Hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQM)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNtRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNtRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQM)

Dynamic and electrical responses of a curved sandwich beam with glass reinforced laminate layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact

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Applied Mathematics and Mechanics(english edition) 2024年第1期45卷 155-178页

作者： N.sHAHVeisi s.FeLi department of mechanical engineering Razi UniversityKermanshah ***Iran

the dynamic responses and generated voltage in a curved sandwich beam with glass reinforced laminate(GRL)layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact(LVi)are *** current study aims to carry out a dynamic analysis on the sandwich beam when the impactor hits the top face sheet with an initial *** the layer analysis,the high-order shear deformation theory(HsDt)and Frostig's second model for the displacement fields of the core layer are *** classical non-adhesive elastic contact theory and Hunter's principle are used to calculate the dynamic responses in terms of *** order to validate the analytical method,the outcomes of the current investigation are compared with those gained by the experimental tests carried out by other researchers for a rectangular composite plate subject to the *** element(Fe)simulations are conducted by means of the ABAQUs *** effects of the parameters such as foam modulus,layer material,fiber angle,impactor mass,and its velocity on the generated voltage are reviewed.

关键词： analytical model piezoelectric layer curved sandwich beam glass reinforced laminate(GRL) pliable core low-velocity impact(LVi) classical non-adhesive elastic contact theory

safe Motion Planning and Control Framework for Automated Vehicles with Zonotopic tRMPC

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engineering 2024年第2期33卷 146-159页

作者： Hao Zheng Yinong Li Ling Zheng ehsan Hashemi state Key Laboratory of mechanical transmissions College of Mechanical and Vehicle EngineeringChongqing UniversityChongqing 400044China department of mechanical engineering University of AlbertaEdmontonAB T6G 2H5Canada

Model mismatches can cause multi-dimensional uncertainties for the receding horizon control strategies of automated vehicles(AVs).the uncertainties may lead to potentially hazardous behaviors when the AV tracks ideal trajectories that are individually optimized by the AV's planning *** address this issue,this study proposes a safe motion planning and control(sMPAC)framework for *** the control layer,a dynamic model including multi-dimensional uncertainties is established.A zonotopic tube-based robust model predictive control scheme is proposed to constrain the uncertain system in a bounded minimum robust positive invariant set.A flexible tube with varying cross-sections is constructed to reduce the controller *** the planning layer,a concept of safety sets,representing the geometric boundaries of the ego vehicle and obstacles under uncertainties,is *** safety sets provide the basis for the subsequent evaluation and ranking of the generated *** efficient collision avoidance algorithm decides the desired trajectory through the intersection detection of the safety sets between the ego vehicle and obstacles.A numerical simulation and hardware-in-the-loop experiment validate the effectiveness and real-time performance of the *** result of two driving scenarios indicates that the sMPAC can guarantee the safety of automated driving under multi-dimensional uncertainties.

关键词： Automated vehicles Automated driving Motion planning Motion control tube MPC Zonotope

Research on the flow stability and noise reduction characteristics of quasi-periodic elastic support skin

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Defence technology（防务技术） 2024年第3期33卷 222-236页

作者： Lu Chen shao-gang Liu Dan Zhao Li-qiang Dong Kai Li shuai tang Jin Cui Hong Guo department of mechanical and electrical engineering Harbin Engineering UniversityHarbin150001China

to enhance flow stability and reduce hydrodynamic noise caused by fluctuating pressure,a quasiperiodic elastic support skin composed of flexible walls and elastic support elements is proposed for fluid noise *** arrangement of the elastic support element is determined by the equivalent periodic distance and quasi-periodic *** this paper,a dynamic model of skin in a fluid environment is *** influence of equivalent periodic distance and quasi-periodic coefficient on flow stability is *** results suggest that arranging the elastic support elements in accordance with the quasi-periodic law can effectively enhance flow ***,the hydrodynamic noise calculation results demonstrate that the skin exhibits excellent noise reduction performance,with reductions of 10 dB in the streamwise direction,11 dB in the spanwise direction,and 10 dB in the normal *** results also demonstrate that the stability analysis method can serve as a diagnostic tool for flow fields and guide the design of noise reduction structures.

关键词： Flow stability Quasi-period Flexible wall elastic support element Hydrodynamic noise