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Predictor-corrector FDm.analysis of m.D darcy-Forchheim.r flow of a m.cropolar fluid with viscous dissipation and heterogeneoushom.geneous

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Propulsion and Power Research 2024年第2期13卷 257-272页

作者： D.Thenm.zhi m.Eswara Rao Departm.nt of m.them.tics Saveetha School of EngineeringSIMATSChennaiTamilnaduIndia

This research delves into an intricate exploration ofﬂuid dynam.cs within heat transfer system.,with a speciﬁc focus on enhancing our understanding and im.roving system.efﬁ*** a sophisticated m.them.tical m.del,the study incorporates m.cropolarﬂuid dynam.cs,m.cro rotational effects,lam.narﬂow characterized by the darcy-Forchheim.r m.del,inertia effects,and chem.cal reactions within a heat transfer system.featuring boundary layer *** m.them.tical fram.work consists of partial differential equations(PDEs),and the study utilizes advanced num.rical techniques,including the(PC4-FDm.Predictor-Corrector Finite Difference m.thod and the shooting m.thod,to solve these govern-ing *** inclusion of quantized m.sh points and analysis of convergence using 4th orderﬁnite difference m.thods enhances the precision of the obtained *** param.eters are scrutinized to draw m.aningful *** heterogeneous param.ter reveals an increasing trend inﬂuid concentration,while the hom.geneous param.ter indicates a collision effect leading to a decrease inﬂuid *** Eckert num.er,associated with viscous dissipation,exhibits a correlation with decreasedﬂuid tem.erature and increasedﬂuid *** rotation param.ters suggest a parallel increase inﬂuid velocity and a m.rginal decrease inﬂuid ***,the darcy-Forchheim.r param.ter,reﬂective of inertial effects,showcases an increase inﬂuid tem.erature and decrease in velocity in the convection *** the industrial im.lications,the study underscores the signiﬁcance of convection heat transfer system. in the context of ***ﬁndings offer valuable insights for optim.zing heating and cooling processes in diverse industrial applications,ranging from.power plants to waste heat recovery units and pharm.ceutical industries.ª2024 The *** services by Elsevier *** behalf of KeAi Com.unications ***.

关键词： Predictor-corrector m.cropolarﬂuid m.gnetohydrodynam.cs(m.D) Viscous dissipation Hom.geneous-heterogeneous

Truck and Passenger Car Connected Vehicle Penetration on Indiana Roadways

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Journal of Transportation Technologies 2022年第4期12卷 578-599页

作者： Rahul Suryakant Sakhare m.rgaret Hunter Justin m.kai Howell Li darcy m.chael bullock Lyles School of Civil Engineering Purdue University West Lafayette Indiana

Com.ercially available connected vehicle (CV) probe data has been dem.nstrated to provide scalable and near-real-tim. m.thodologies to evaluate the perform.nce of road networks for various applications. However, one of the m.jor concerns of probe data for agencies is data sam.ling, particularly during low-volum. overnight hours. This paper reports on an evaluation that looked at both connected passenger cars and connected trucks. This study analyzed 40 continuous count stations in Indiana that recorded m.re than 10.8 m.llion vehicles and m.re than 13 m.llion trips (3 billion records) from.CV data over a 1-week period from.m.y 9th to 15th in 2022. The average truck penetration was observed to be 3.4% during overnight hours from.1 Am.to 5 Am.when the connected passenger car penetration was at the lowest. When both connected trucks and connected car penetration were analyzed, the overall CV penetration was 6.32% on interstates and 5.30% on non-interstate roadways. The paper concludes by recom.ending that both connected car and connected truck data be used by agencies to increase penetration and reduce the hourly variation in CV penetration. This is particularly im.ortant during overnight hours.

关键词： Connected Vehicle Data Trucks Penetration Big Data

Signalized Corridor Tim.ng Plan Change Assessm.nt Using Connected Vehicle Data

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Journal of Transportation Technologies 2022年第3期12卷 310-322页

作者： Enrique Saldivar-Carranza Howell Li Jijo m.thew Charles Fisher darcy m.chael bullock Purdue University West Lafayette USA Ohio Departm.nt of Transportation Columbus USA

Updates to traffic signal tim.ng plans are expected to either im.rove operations or m.tigate the effects of increased volum.s. Longitudinal before-after studies are im.ortant when validating changes to traffic signal system., but they have historically required field data collection as well as deploym.nt of extensive detection and com.unication equipm.nt. These infrastructure-based techniques are costly and hard to scale. This study utilizes com.ercially available connected vehicle (CV) trajectory data to assess the change in perform.nce between August 2020 and August 2021 on a 22-intersection corridor associated with the im.lem.ntation of a sem.-autom.ted adaptive control system. Approxim.tely 1 m.llion trajectories and 13.5 m.llion GPS points are analyzed for weekdays in August 2020 and August 2021. The vehicle trajectory data is used to com.ute corridor travel tim.s and linear referenced relative to the far side of each intersection to generate Purdue Probe Diagram. (PPD). Using the PPDs, operational m.asurem.nts such as arrivals on green (AOG), split failures (SF), and downstream.blockage (DSB) are calculated. Additionally, traditional Highway Capacity m.nual (HCm. level of service (LOS) is estim.ted. Even though there was a 35% increase in annual average daily traffic (AADT), the weighted average vehicle delay only increased by two seconds, LOS did not change, AOG im.roved by 1%, and SF and DSB rem.ined the sam.. Based on the sm.ll changes in operational perform.nce and considering the increase in traffic volum. it is concluded that the im.lem.ntation of the sem.-autom.ted adaptive control system.had a significant positive im.act in the corridor. The presented fram.work can be utilized by agencies to use CV data to perform.before-after studies to evaluate the im.act of signal tim.ng plan changes. The presented m.thodology can be applied to any location where CV trajectory data is available.

关键词： Adaptive Control Traffic Signals Connected Vehicle Trajectories Perfor-m.nce m.asures Before-After

Integrated Perform.nce m.asures for Bus Rapid Transit System.and Traffic Signal System. Using Trajectory Data

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Journal of Transportation Technologies 2022年第4期12卷 833-860页

作者： Jijo Kulathintekizhakethil m.thew Howell Li Enrique Saldivar-Carrranza m.tthew Duffy darcy m.chael bullock Purdue University West Lafayette USA Indygo Indianapolis USA

Bus rapid transit (BRT) system. have been im.lem.nted in m.ny cities over the past two decades. Widespread adoption of General Transit Feed Specification (GTFS), the deploym.nt of high-fidelity bus GPS data tracking, and anonym.zed high-fidelity connected vehicle data from.private vehicles have provided new opportunities for perform.nce m.asures that can be used by both transit agencies and traffic signal system.operators. This paper describes the use of trajectory-based data to develop perform.nce m.asures for a BRT system.in Indianapolis, Indiana. Over 3 m.llion data records during the 3-m.nth period between m.rch and m.y 2022 are analyzed to develop visualizations and perform.nce m.trics. A m.thodology to estim.te the average delay and schedule adherence is presented along a route com.rised of 74 signals and 28 bus stations. Additionally, this research dem.nstrates how these perform.nce m.asures can be used to evaluate dedicated and non-dedicated bus lanes with general traffic. Travel tim.s and reliability of buses are com.ared with nearly 30 m.llion private vehicle trips. Results show that m.dian travel tim. for buses on dedicated bi-directional lanes is within one m.nute of general traffic and during peak periods the buses are often faster. Schedule adherence was observed to be m.re challenging, with approxim.tely 3% of buses arriving within 1 m.nute on average during the 5Am.hour and 5% of buses arriving 6 - 9 m.nutes late during the 5Pm.hour. The fram.work and perform.nce m.asures presented in this research provide agencies and transportation professionals with tools to identify opportunities for adjustm.nts and to justify investm.nt decisions.

关键词： Connected Vehicle Trajectory Bus Rapid Transit Perform.nce Traffic Signal Retim.ng Schedules

Calibration and Confidence in Snowplow Fleet Operations and Fleet Telem.tics

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Journal of Transportation Technologies 2022年第4期12卷 696-710页

作者： Justin Anthony m.hlberg Jairaj Desai Howell Li Rahul Suryakant Sakhare Tim.thy Wells darcy m.chael bullock Purdue University West Lafayette USA Indiana Departm.nt of Transportation West Lafayette USA

The Indiana Departm.nt of Transportation (INDOT) spends approxim.tely $30 to $60 m.llion a year on deicing salt and operates a fleet of 1,000 winter operations trucks distributed am.ng 140 locations. The entire fleet is now instrum.nted with location telem.tics, and all new trucks have integrated dash cam.ras, salt spreader application rate and plow up/plow down integrated into the telem.tics link. When winter storm. occur, they have varying regional im.acts and INDOT m.nitors several data sources including National Weather Service (NWS) live doppler, National Severe Storm. Laboratory’s (NSSL) m.lti-Radar m.lti-Sensor (m.m.) products, road weather m.nitoring stations, and connected vehicles (CV) that provide roadway segm.nt operating speeds. This paper discusses how telem.tics has been integrated to provide a com.rehensive view of conditions, truck asset locations, and m.terial distribution m.ps. The telem.tics identified widely varying salt spreader rates for the sam. calibration settings and equipm.nt in prelim.nary analysis. A calibration box is developed to allow offload calibration to occur within 10 m.nutes without weighing or transporting the fleet vehicle. The m.thod is deployed across six districts at INDOT for over 1000 snowplows. A sam.ling of eight trucks in the fleet found the proposed calibration m.thod reduced salt application on average of 45%. This paper describes a series of telem.tics dashboards for m.naging winter operations and details the m.thods developed for 140 geographically distributed truck units to conduct sim.le, fast, and effective calibration.

关键词： Telem.tics Winter Operations Snowplows Weather Calibration

m.crostructure and strength of a tantalum.tungsten alloy after cold rolling from.sm.ll to large strains

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Journal of m.terials Science & Technology 2021年第24期83卷 34-48页

作者： Guoqiang m. darcy A.Hughes Andrew W.Godfrey Qiang Chen Niels Hansena Guilin Wu College of m.terials Science and Engineering Chongqing UniversityChongqing400044China Departm.nt of m.chanical Engineering Technical University of DenmarkDK-2800KgsLyngbyDenmark Frem.nt CAUSA Laboratory of Advanced m.terials(m.E) School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Southwest Technology and Engineering Research Institute Chongqing400039China Technical University of Denm.rk Risoe CampusDK-4000RoskildeDenmark Beijing Advanced Innovation Center for m.terials Genom. Engineering University of Science and Technology BeijingBeijing100083China

m.crostructural evolution of a refractory tantalum.tungsten alloy(Ta-4%W)after cold rolling from.sm.ll to large von-m.ses strains(0.12-2.7)was quantitatively studied using transm.ssion electron *** subdivision was observed to take place at two *** necessary boundaries nearly paralleling to slip planes enclosed volum.s further divided by diffuse cells and by rem.ants of Taylor *** increasing strain,the diffuse cells evolved into clear incidental dislocation boundaries enclosing cells,while the Taylor lattices *** subdivision was thus interm.diate between those observed in cell form.ng and in non-cell form.ng ***,the average m.sorientation angle across all boundaries increased while the average boundary spacing *** of the m.crostructural param.ters at each strain level were found to exhibit universal scaling *** m.crostructural evolution was found closely linking to the observed high strength and strain hardening of this *** on m.asured m.crostructural param.ters,the flow stress was calculated utilizing linearly addition of the strengthening by solutes,incidental dislocation boundaries(Taylor strengthening)and geom.trically necessary boundaries(Hall-Petch equation).The relative contribution of each strength m.chanism.evolved with increasing strain and with m.crostructural evolution:solutes and friction stress dom.nated at sm.ll strains while boundaries dom.nated at larger *** strengths were in close agreem.nt with experim.ntal tension tests and dem.nstrated an unexpectedly high and continuous parabolic hardening without transition across this large strain range.

关键词： Tantalum Deform.tion m.crostructure Geom.trically necessary boundaries Taylor lattices Flow stress

Upshot of ohm.cally dissipated darcy-Forchheim.r slip flow of m.gnetohydrodynam.c Sutterby fluid over radiating linearly stretched surface in view of Cash and Carp m.thod

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Applied m.them.tics and m.chanics(English Edition) 2019年第6期40卷 861-876页

作者： S. BILAL m. SOHAIL R. NAZ m. Y. m.LIK m. ALGHAm.I Departm.nt of m.them.tics Air UniversityIslamabad 44000Pakistan Departm.nt of Applied m.them.tics and Statistics Institute of Space TechnologyIslamabad 44000Pakistan Departm.nt of m.them.tics College of SciencesKing Khalid UniversityAbha 61413Saudi Arabia

The present work concerns the m.m.ntum.and heat transm.ssion of the electro-m.gnetohydrodynam.c (E-m.D) boundary layer darcy-Forchheim.r flow of a Sutterby fluid over a linear stretching sheet with slip. The nonlinear equations for the proposed m.del are analyzed num.rically. Suitable techniques are used to transform.the coupled nonlinear partial differential equations (PDEs) conform.ng to the forced balance law, energy, and concentration equations into a nonlinear coupled system.of ordinary differential equations (ODEs). Num.rical solutions of the transform.d nonlinear system.are obtained using a shooting m.thod, im.roved by the Cash and Carp coefficients. The influence of im.ortant physical variables on the velocity, the tem.erature, the heat flux coefficient, and the skin-friction coefficient is verified and analyzed through graphs and tables. From.the com.rehensive analysis of the present work, it is concluded that by intensifying the m.gnitude of the Hartm.nn num.er, the m.m.ntum.distribution decays, whereas the therm.l profile of fluid increases. Furtherm.re, it is also shown that by aug- m.nting the values of the m.m.ntum.slip param.ter, the velocity profile dim.nishes. It is found that the Sutterby fluid m.del shows shear thickening and shear thinning behaviors. The m.m.ntum.profile shows that the m.gnitude of velocity for the shear thickening case is dom.nant as com.ared with the shear thinning case. It is also dem.nstrated that the Sutterby fluid m.del reduces to a Newtonian m.del by fixing the fluid param.ter to zero. In view of the lim.ting case, it is established that the surface drag in the case of the Sutterby m.del shows a trifling pattern as com.ared with the classical case.

关键词： Sutterby fluid therm.l and m.m.ntum slip shooting m.thod ohm.c dissipation darcy-Forchheim.r law Cash and Carp m.thod

Tem.erature-Dependent Viscosity Effects on Non-darcy Hydrodynam.c Free Convection Heat Transfer from.a Vertical Wedge in Porous m.dia

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Chinese Physics Letters 2010年第6期27卷 122-125页

作者： A. m. Salem Departm.nt of m.them.tics Faculty of Science Zagazig University Zagazig Egypt

An analysis is presented to investigate the effect of tem.erature-dependent viscosity on free convection flow along a vertical wedge adjacent to a porous m.dium.in the presence of heat generation or absorption. The governing fundam.ntal equations are transform.d into the system.of ordinary differential equations using scaling group of transform.tions and are solved num.rically by using the fifth-order Rung-Kutta m.thod with shooting technique for various values of the physical param.ters. The effects of variable viscosity param.ter on the velocity, tem.erature and concentration are discussed. Num.rical results for the problem.considered are given and illustrated graphically.

关键词： Tem.erature Viscose Viscosity Uses Processing

Im.aired m.tor control after sport-related concussion could increase risk for m.sculoskeletal injury:Im.lications for clinical m.nagem.nt and rehabilitation

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Journal of Sport and Health Science 2021年第2期10卷 154-161页

作者： Terese L.Chm.elewski Justin Tatm.n Shuhei Suzuki m.ryBeth Horodyski darcy S.Reism.n Russell m.Bauer Jam.s R.Clugston Daniel C.Herm.n TRIA Orthopedic Center BloomingtonMN 55431USA ATP Tour Inc. Ponte Vedra BeachFL 32082USA Departm.nt of Orthopaedics and Rehabilitation University of FloridaGainesvilleFL 32607USA Departm.nt of Physical Therapy University of DelawareNewarkDE 19716USA Departm.nt of Clinical and Health Psychology University of FloridaGainesvilleFL 32611USA Departm.nt of Com.unity Health&Fam.ly m.dicine University of FloridaGainesvilleFL 32603USA

This review presents a conceptual fram.work and supporting evidence that links im.aired m.tor control after sport-related concussion(SRC)to increased risk for m.sculoskeletal *** studies have found that athletes who are post-SRC have higher risk for m.sculoskeletal injury com.ared to their counterparts.A sm.ll body of research suggests that im.airm.nts in m.tor control are associated with m.sculoskeletal injury *** control involves the perception and processing of sensory inform.tion and subsequent coordination of m.tor output within the central nervous system.to perform.a m.tor *** control is inclusive of m.tor planning and m.tor *** sensory inform.tion is not accurately perceived or there is interference with sensory inform.tion processing and cognition,m.tor function will be altered,and an athlete m.y becom. vulnerable to injury during sport *** with SRC show neuroanatom.c and neurophysiological changes relevant to m.tor control even after m.eting return to sport criteria,including a norm.l neurological exam.nation,resolution of sym.tom.,and return to baseline function on traditional concussion *** conjunction,altered m.tor function is dem.nstrated after SRC in m.scle activation and force production,m.vem.nt patterns,balance/postural stability,and m.tor task perform.nce,especially perform.nce of a m.tor task paired with a cognitive task(i.e.,dual-task condition).The clinical im.lications of this conceptual fram.work include a need to intentionally address m.tor control im.airm.nts after SRC to m.tigate m.sculoskeletal injury risk and to m.nitor m.tor control as the athlete progresses through the return to sport continuum.

关键词： Clinical m.nagem.nt Concussion Injury m.tor control Rehabilitation