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1.
In this paper, a new lattice hydrodynamic model is proposed by incorporating the driver anticipation effect of next-nearest-neighbor site. The linear stability analysis and nonlinear analysis show that the driver anticipation effect of next-nearest-neighbor site can enlarge the stable area of traffic flow. The space can be divided into three regions: stab/e, metastable, and unstable. Numerical simulation further illuminates that the driver anticipation effect of the next-neaxest-neighbor site can stabilize tramc flow in our modified lattice model, which is consistent with the analytical results. 相似文献
2.
In this paper, a new lattice hydrodynamic model is proposed by incorporating the driver anticipation effect of next-nearest-neighbor site. The linear stability analysis and nonlinear analysis show that the driver anticipation effect of next-nearest-neighbor site can enlarge the stable area of traffic flow. The space can be divided into three regions: stable, metastable, and unstable. Numerical simulation further illuminates that the driver anticipation effect of the next-nearest-neighbor site can stabilize traffic flow in our modified lattice model, which is consistent with the analytical results. 相似文献
3.
In this paper,a new lattice model of two-lane trafc flow with the honk efect term is proposed to study the influence of the honk efect on wide moving jams under lane changing.The linear stability condition on two-lane highway is obtained by applying the linear stability theory.The modified Korteweg-de Vries(KdV)equation near the critical point is derived and the coexisting curves resulted from the modified KdV equation can be described,which shows that the critical point,the coexisting curve and the neutral stability line decrease with increasing the honk efect coefcient.A wide moving jam can be conceivably described approximately in the unstable region.Numerical simulation is performed to verify the analytic results.The results show that the honk efect could suppress efectively the congested trafc patterns about wide moving jam propagation in lattice model of two-lane trafc flow. 相似文献
4.
Ramps and sloping roads appear everywhere in the built environment. It is obvious that the movement pattern of people in the sloping path may be different as compared with the pattern on level roads. Previously, most of the studies, especially the mathematical and simulation models, on pedestrian movement consider the flow at level routes.This study proposes a new lattice model for bidirectional pedestrian flow on gradient road. The stability condition is obtained by using linear stability theory. The nonlinear analysis method is employed to derive the modified Korteweg-de Vries(mKdV) equation, and the space of pedestrian flow is divided into three regions: the stable region, the metastable region, and the unstable region respectively. Furthermore, the time-dependent Ginzburg–Landan(TDGL) equation is deduced and solved through the reductive perturbation method. Finally, we present detailed results obtained from the model, and it is found that the stability of the model is enhanced in uphill situation while reduced in downhill situation with increasing slope. 相似文献
5.
Ramps and sloping roads appear everywhere in the built environment. It is obvious that the movement pattern of people in the sloping path may be different as compared with the pattern on level roads. Previously, most of the studies, especially the mathematical and simulation models, on pedestrian movement consider the flow at level routes. This study proposes a new lattice model for bidirectional pedestrian flow on gradient road. The stability condition is obtained by using linear stability theory. The nonlinear analysis method is employed to derive the modified Korteweg-de Vries (mKdV) equation, and the space of pedestrian flow is divided into three regions: the stable region, the metastable region, and the unstable region respectively. Furthermore, the time-dependent Ginzburg—Landan (TDGL) equation is deduced and solved through the reductive perturbation method. Finally, we present detailed results obtained from the model, and it is found that the stability of the model is enhanced in uphill situation while reduced in downhill situation with increasing slope. 相似文献
6.
A feedback control model of lattice hydrodynamic model is proposed by taking the information of the historic optimal velocity into account for the traffic system. The modern control theory is applied for the linear stability condition with feedback control signal. The result shows that the stability of traffic flow is closely related to the information of the historic optimal velocity. Furthermore, numerical simulations conform that the new feedback control did increase the stability of traffic flow efficiently, which is in accord with theoretical analysis. 相似文献
7.
PENG Guang-Han 《理论物理通讯》2013,60(4):485-490
In this paper, a new lattice model of two-lane traffic flow with the honk effect term is proposed to study the influence of the honk effect on wide moving jams under lane changing. The linear stability condition on two-lane highway is obtained by applying the linear stability theory. The modified Korteweg-de Vries (KdV) equation near the critical point is derived and the coexisting curves resulted from the modified KdV equation can be described, which shows that the critical point, the coexisting curve and the neutral stability line decrease with increasing the honk effect coefficient. A wide moving jam can be conceivably described approximately in the unstable region. Numerical simulation is performed to verify the analytic results. The results show that the honk effect could suppress effectively the congested traffic patterns about wide moving jam propagation in lattice model of two-lane traffic flow. 相似文献
8.
In this article, a discrete effect in the thermal Lattice BGK two-speed model is studied. These effects are due to the non-equilibrium state in the particle distribution function, and the non-equilibrium occurs near walls. The mechanism of the LBM counterpart of the thermal creep flow, which appears due to the temperature gradient of the boundary in rarefied gases, is clarified analytically and numerical calculations are performed for some cases. A technique for eliminating this effect is also shown. 相似文献
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A Diffusively Corrected Multiclass Lighthill-Whitham-Richards Traffic Model with Anticipation Lengths and Reaction Times 下载免费PDF全文
Raimund Bü rger Pep Mulet & Luis M. Villada 《advances in applied mathematics and mechanics.》2013,5(5):728-758
Multiclass Lighthill-Whitham-Richards traffic models [Benzoni-Gavage and
Colombo, Euro. J. Appl. Math., 14 (2003), pp. 587–612; Wong and Wong, Transp. Res.
A, 36 (2002), pp. 827–841] give rise to first-order systems of conservation laws that are
hyperbolic under usual conditions, so that their associated Cauchy problems are well-posed. Anticipation lengths and reaction times can be incorporated into these models
by adding certain conservative second-order terms to these first-order conservation
laws. These terms can be diffusive under certain circumstances, thus, in principle, ensuring the stability of the solutions. The purpose of this paper is to analyze the stability of these diffusively corrected models under varying reaction times and anticipation
lengths. It is demonstrated that instabilities may develop for high reaction times and
short anticipation lengths, and that these instabilities may have controlled frequencies
and amplitudes due to their nonlinear nature. 相似文献
12.
In this letter,we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer,specifically for solar energy utilization through an unglazed transpired solar air collector(UTC).Besides the lattice Boltzmann equation(LBE) for time evolution of particle distribution function for fluid field,we introduce an analogy,LBE for time evolution of distribution function for temperature.Both temperature fields of fluid(air) and solid(porous media) are modeled.We study the effects of fan velocity,solar radiation intensity,porosity,etc.on the thermal performance of the UTC.In general,our simulation results are in good agreement with what in literature.With the current system setting,both fan velocity and solar radiation intensity have significant effect on the thermal performance of the UTC.However,it is shown that the porosity has negligible effect on the heat collector indicating the current system setting might not be realistic.Further examinations of thermal performance in different UTC systems are ongoing.The results are expected to present in near future. 相似文献
13.
ZHU Wen-Xing 《理论物理通讯》2008,50(9):753-756
An optimai current lattice model with backward-looking effect is proposed to describe the motion of traffic flow on a single lane highway. The behavior of the new model is investigated anaiytically and numerically. The stability, neutrai stability, and instability conditions of the uniform flow are obtained by the use of linear stability theory. The stability of the uniform flow is strengthened effectively by the introduction of the backward-looking effect. The numerical simulations are carried out to verify the validity of the new model. The outcomes of the simulation are corresponding to the linearly analyticai results. The analytical and numerical results show that the performance of the new model is better than that of the previous models. 相似文献
14.
Zhaoli Guo & Kun Xu 《advances in applied mathematics and mechanics.》2009,1(3):391-401
Recently Brenner [Physica A 349, 60 (2005)] proposed a
modified Navier-Stokes set of equations. Based on some theoretical
arguments and some limited experiments, the model is expected to be
able to describe flows with a finite Knudsen number. In this work,
we apply this model to the plane Poiseuille flow driven by a force,
and compare the results with the Direct Simulation Monte Carlo
(DSMC) measurements. It is found that Brenner's model is inadequate
for flows with a finite Knudsen number. 相似文献
15.
A decorated lattice is suggested and the Ising model on it with three kinds
of interactions K1,
K2, and
K3 is studied. Using an equivalent transformation, the square decorated Ising lattice is transformed into a regular square Ising lattice with nearest-neighbor, next-nearest-neighbor, and four-spin interactions, and the critical fixed point is found at
K1=0.5769,
K2=-0.0671, and
K3=0.3428, which determines the critical temperature of the system. It is also found that this system and
the regular square Ising lattice, and the eight-vertex model belong to the
same universality class. 相似文献
16.
ZHU Wen-Xing 《理论物理通讯》2008,50(3):753-756
An optimal current lattice model with backward-looking effect is proposed to describe the motion of traffic flow on a single lane highway. The behavior of the new model is investigated analytically and numerically. The stability, neutral stability, and instability conditions of the uniform flow are obtained by the use of linear stability theory. The stability of the uniform flow is strengthened effectively by the introduction of the backward-looking effect. The numerical simulations are carried out to verify the validity of the new model. The outcomes of the simulation are corresponding to the linearly analytical results. The analytical and numerical results show that the performance of the new model
is better than that of the previous models. 相似文献
17.
Daniel Gandolfo Lahoussine Laanait Salvador Miracle-Sole Jean Ruiz 《Journal of statistical physics》2007,126(1):133-156
Within a semi-infinite three-dimensional lattice gas model describing the coexistence of two phases on a substrate, we study,
by cluster expansion techniques, the free energy (line tension) associated with the contact line between the two phases and
the substrate. We show that this line tension, is given at low temperature by a convergent series whose leading term is negative,
and equals 0 at zero temperature. 相似文献
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Lattice Boltzmann (LB) modeling of high-speed compressible flows has long been attempted by various authors. One common weakness of most of previous models is the instability problem when the Mach number of the flow is large. In this paper we present a finite-difference LB model, which works for flows with flexible ratios of specific
heats and a wide range of Mach number, from $0$ to 30 or higher. Besides the discrete-velocity-model by Watari [Physica A 382 (2007) 502], a modified Lax--Wendroff finite difference
scheme and an artificial viscosity are introduced. The combination of the finite-difference scheme and the adding of artificial viscosity must find a balance of numerical stability versus
accuracy. The proposed model is validated by recovering results of
some well-known benchmark tests: shock tubes and shock reflections.
The new model may be used to track shock waves and/or to study the
non-equilibrium procedure in the transition between the regular and
Mach reflections of shock waves, etc. 相似文献