基于1D/3D耦合仿真的汽油机EGR均匀性优化

基于某4缸带外部废气再循环(exhaust gas recycle,EGR)功能的自然吸气汽油机,采用1D热力学和3DCFD耦合仿真的方法研究了部分负荷工况各缸EGR分配的均匀性,并在性能台架上研究了EGR分配不均对各缸燃烧速度的影响。研究结果表明:缸内实际EGR均匀性不仅与EGR系统设计有关,同时也受到各缸进气的均匀性的影响;EGR的不合理分配会导致各缸燃烧速率不均,继而增大燃烧循环波动率。基于所建立的1D/3D耦合分析方法,对EGR分配孔板结构进行了详细仿真优化,EGR分配均匀性得到显著改善。在随后的试验中,各缸燃烧一致性明显改善。

1D/3D Coupling Calculation Analysis on Bus Cooling System

Compared with front engine vehicle, the windward side’s flow field in cooling model of rear engine bus is complicated and it can’t be calculated by means of 1D model. For this problem, this paper has used Star-CCM to build a 3D simulation model of cooling system, engine compartment and complete vehicle. Then, it had a 1D/3D coupling calculation on cooling system with Kuli software. It could be helpful in the optimization design of the flow field of rear engine compartment and optimization match of cooling system.

基于1D/3D的运行起始期对地下水源能量利用系统性能的影响分析

本文通过Matlab与Fluent软件建立了热泵系统1D/3D闭环耦合计算平台,可以提前预测热泵系统不同运行模式系统运行参数。通过分析计算平台结果得出如下结论:从抽水井群抽水年平均温度可以看出,从冬季开始运行的系统,抽水井群从地下含水层抽水年平均温度稍高,从夏季制冷期系统EER分析同样可以看出,系统从冬季开始运行系统EER同样稍高于系统从夏季开始运行模式。夏启运行模式对于保持地下含水层温度稳定较为有利,更加有助于保证系统的长期稳定运行,夏启运行模式系统的能效比稍高于冬启运行模式。

基于1D/3D的流量调配比例对交叉流模式热泵性能的影响

本文基于1D/3D集成分析数值方法的基础上,分析流量调配模式对垂直交叉流系统性能参数的变化。结果表明:对于地下水源热泵系统,如果地下水流为垂直交叉流,通过调整抽水井群抽水量、回灌井群的回流量,将对系统性能参数产生不同的影响。在系统运行周期内,对于垂直交叉流,位于地下水流上游的抽水井群和回灌井群流量分配占比越小,供暖周期内抽水井群从地下含水层的抽水温度整体就越高,与此同时热泵机组COP和系统能耗比也就越大,通过仿真模拟可以看出,地下含水层温度稳定性越好,越有利维持于系统长期稳定运行。

某PHEV车型电池热管理系统的1D/3D耦合分析

采用1D/3D耦合仿真的手段对某PHEV车型电池包热管理系统进行了研究。1D建模方法用于建立电芯的等效电路模型,模型用试验数据标定,能预测电芯的发热量,并为3D仿真提供输入。3D仿真能够计算电芯内部的温度分布,而温度会影响1D等效电路的模型参数,进而影响发热量,以这种方式建立了仿真模型的1D/3D双向耦合。利用此模型,以一组高温恶劣工况下实测电池电流和电池包进口处冷却液温度为边界条件进行了瞬态分析,并将冷却液出口水温仿真结果与试验数据进行对比,结果显示两者平均偏差在1℃以内,体现出较好的预测效果。研究结果还显示,电池包外表面空气对流传递的热量在总散热量的5%以内,对结果影响不大。研究证明1D/3D耦合仿真是新能源车型电池包开发过程中的有力工具。

基于Flowmaster的雷达阵面管网1D-3D流动传热联合仿真

为研究某雷达阵面管网系统的流量分配,采用1D-3D联合仿真方法对阵面进行流动与传热仿真。首先采用一维系统级仿真软件Flowmaster对阵面进行一维建模,并通过三维仿真软件FloEFD对水接头以及冷板组件进行详细的流动仿真,获得其流量-流阻变化关系,并将结果带入Flowmaster软件中得到拟合曲线,定义一维模型各元件参数进行阵面流动与传热仿真计算,实现1D-3D联合仿真。结果表明,经优化后的阵面各支路流量差异低于1.5%,且阵面温度分布均匀。文中还研究了插拔组件对阵面流量分配的影响,各支路流量差异低于2%。通过1D-3D联合仿真研究,可以实现高精度流量分配并获得直观的阵面详细仿真结果,并且大大节省了计算时间与研发成本,对今后雷达阵面流量分配设计具有重要的参考价值。

3D ZnIn_(2)S_(4)微球/1D TiO_(2)纳米带异质结构的光催化降解和还原性能

首先采用溶剂热法和高温煅烧法制备1D TiO_(2)纳米带,其次利用溶剂热法将1D TiO_(2)纳米带均匀地穿插到片层结构组装而成的3D ZnIn_(2)S_(4)微球中,所形成的异质结构能有效抑制光生电子-空穴的复合。二元ZnIn_(2)S_(4)微球/TiO_(2)纳米带复合光催化剂在高浓度染料罗丹明B(RhB)的光降解和Cr(VI)的光还原实验中表现出优异的性能。在模拟太阳光照射下,ZnIn_(2)S_(4)/TiO_(2)纳米带光催化降解RhB和还原Cr(VI)的效率相较于纯TiO_(2)颗粒(10%,22%)、TiO_(2)纳米带(45%,40%)、ZnIn_(2)S_(4)(62%,65%)、ZnIn_(2)S_(4)/TiO_(2)颗粒(90%,91%)分别提高至100%和100%。最后,通过紫外-可见DRS光谱和M-S曲线分析,提出了适合该体系的光催化反应机理。

基于1D/3D协同仿真流量与温差调控模式影响分析

针对地下水源能量利用系统建筑负荷的动态变化,基于1D/3D集成分析数值方法的基础上,分析了定流量变温差及定温差变流量两时变模式系统性能参数的变化。结果表明：定温差变流量调控模式由于抽水量小于定流量变温差模式,含水层发生热贯通时间较晚;发生热贯通后,由于抽水温差大于定流量变温差模式,冷水封面向抽水井移动速度较快,抽水温度下降幅度较大,热贯通程度显著。抽灌水流量对热贯通起主导作用,热贯通发生后抽灌水温差对地下水温度影响较大;定温差变流量模式机组的COP值迅速下降,运行过程中耗功较少,系统能效比较大。

3D motion and geometric information system of single-antenna radar based on incomplete 1D range data

A 3D motion and geometric information system of single-antenna radar is proposed,which can be supported by spotlight synthetic aperture radar（SAR） system and inverse SAR（ISAR） system involving relative 3D motion of the rigid target.In this system,applying the geometry invariance of the rigid target,the unknown 3D shape and motion of the radar target can be reconstructed from the 1D range data of some scatterers extracted from the high-resolution range image.Compared with the current 1D-to-3D algorithm,in the proposed algorithm,the requirement of the 1D range data is expanded to incomplete formation involving large angular motion of the target and hence,the quantity of the scatterers and the abundance of 3D motion are enriched.Furthermore,with the three selected affine coordinates fixed,the multi-solution problem of the reconstruction is solved and the technique of nonlinear optimization can be successfully utilized in the system.Two simulations are implemented which verify the higher robustness of the system and the better performance of the 3D reconstruction for the radar target with unknown relative motion.

基于1D和3D耦合的发动机进气歧管仿真研究

进气系统在很大程度上影响了发动机的动力性、经济性和排放性。前期建立了一维仿真模型,比较真实的反映了发动机的性能,但还是未能真实的反映出管道的真实结构,像一些拐角、突变区域等。进气歧管的设计校验中,虽然三维稳态和瞬态计算能够模拟各个支管的压力分布情况,但是仅用三维计算不能实时得到一维的准确边界,且计算时间太长,不能从整个发动机上模拟瞬态进气过程和谐振效应带来的进气不均匀性。因此,要在1D模型中获得更准确的瞬态边界条件来计算进气歧管的三维流动,或更进一步研究进气歧管结构形状对发动机性能的影响,来指导优化进气歧管的设计。文章以发动机1D燃烧开发软件为基础与3D流体软件相耦合来解决进气歧管设计中瞬态进气过程。

One New 3D Pillared-layer Ag(Ⅰ)-Coordination Framework Based on a Unique 1D Ag2O2 Ribbon： Synthesis,Crystal Structure and Luminescent Properties

A new 3D Ag（I） coordination polymer {[Ag（AZDB）（0.5）（bpe）（0.5）]·H2O}n（1） has been papared by azobenzene-3,3？-dicarboxylicate（H2AZDB）, 1,2-bis（4-pyridyl）ethylene（bpe） and silver salts via hydrothermal method. The compound was fully characterized by single-crystal X-ray diffraction, elemental analyses, infrared spectrum（IR）, powder X-ray diffraction（PXRD） and thermogravimetric analysis（TGA）. The strucrural analysis indicate that compound 1 shows a 3D pillared-layer framework constructed from a unique 1D Ag2O2 ribbon and pyridyl/carboxylicate mixed system, which features a 2-nodal（4, 6）-connected fsc net with a（4^4·6^10·8）（4^4·6^2） topology.Moreover, the photoluminescent properties have also been discussed.

A Local Contrast Fusion Based 3D Otsu Algorithm for Multilevel Image Segmentation

To overcome the shortcomings of 1 D and 2 D Otsu’s thresholding techniques, the 3 D Otsu method has been developed.Among all Otsu’s methods, 3 D Otsu technique provides the best threshold values for the multi-level thresholding processes. In this paper, to improve the quality of segmented images, a simple and effective multilevel thresholding method is introduced. The proposed approach focuses on preserving edge detail by computing the 3 D Otsu along the fusion phenomena. The advantages of the presented scheme include higher quality outcomes, better preservation of tiny details and boundaries and reduced execution time with rising threshold levels. The fusion approach depends upon the differences between pixel intensity values within a small local space of an image;it aims to improve localized information after the thresholding process. The fusion of images based on local contrast can improve image segmentation performance by minimizing the loss of local contrast, loss of details and gray-level distributions. Results show that the proposed method yields more promising segmentation results when compared to conventional1 D Otsu, 2 D Otsu and 3 D Otsu methods, as evident from the objective and subjective evaluations.

A Comparative Study on the Truck Frame Stiffness with Solid and Beam Element FEA Models

Truck frames should be designed and fabricated with enough rigidity to avoid excessive deflections. Finite element analysis (FEA) plays an important role in all stages of frame designs. While being accurate, 3D solid element FEA models are built upon frame configuration details which are not feasible in the preliminary design stage, partially because of limited available design data of frames and heavy computation costs. This research develops 1D beam element FEA models for simulating frame structures. In this paper, the CAD model of a truck frame is first created. The solid element FEA analysis, which is adopted as the baseline in this study, is subsequently conducted for the stiffness of the frame, Next, beam element FEA analysis is performed for validating the feasibility of the beam element FEA model by comparing the results from the solid and beam element FEA models. It is found that the beam element FEA model can predict the frame stiffness with acceptable accuracy and reduce the computation cost significantly.

微孔配位聚合物[Gd(H_2betc)_(0.5)(betc)_(0.5)(H_2O)]_n·2nH_2O的合成及晶体结构研究

本文报道了一个新的微孔配位聚合物:[Gd(H2betc)0.5(betc)0.5(H2O)]n·2nH2O(H4betc=1,2,4,5-Benzenetetracarboxylic acid,均苯四甲酸)。通过X射线单晶衍射仪测定其晶体结构,并进行了元素分析,红外等性质测定。晶体结构研究结果表明,其结构为单斜晶系,空间群为P21/n。Gd(Ⅲ)离子通过氧原子的桥连作用形成一条Gd-O链,Gd-O链再通过均苯四甲酸配体的桥连作用,形成Gd-betc层结构。Gd-betc层进一步通过均苯四甲酸配体的桥连作用形成具有一维孔道的三维网状结构。扣除孔道中的水分子,这个结构中的孔洞率约为17.6%。

基于CFD的某轻客冷却系统性能三维、一维耦合分析

文章利用商用三维计算流体力学(CFD)软件和一维仿真软件相结合,对某型车机舱内外流场进行模拟分析,得到发动机舱内外流场特性,并对流场进行优化,提升通过散热器的风量。然后通过一维软件对整车冷却系统的性能性能匹配分析并与实验数据进行对比,结果表明,分析结果与实验结果吻合度较高。

Recursive super-convergence computation for multi-dimensional problems via one-dimensional element energy pro jection technique

This paper presents a strategy for computation of super-convergent solutions of multi-dimensional problems in the finite element method （FEM） by recursive application of the one-dimensional （1D） element energy projection （EEP） technique. The main idea is to conceptually treat multi-dimensional problems as generalized 1D problems, based on which the concepts of generalized 1D FEM and its consequent EEP formulae have been developed in a unified manner. Equipped with these concepts, multi-dimensional problems can be recursively discretized in one dimension at each step, until a fully discretized standard finite element （FE） model is reached. This conceptual dimension-by- dimension （D-by-D） discretization procedure is entirely equivalent to a full FE discretization. As a reverse D-by-D recovery procedure, by using the unified EEP formulae together with proper extraction of the generalized nodal solutions, super-convergent displacements and first derivatives for two-dimensional （2D） and three-dimensional （3D） problems can be obtained over the domain. Numerical examples of 3D Poisson＇s equation and elasticity problem are given to verify the feasibility and effectiveness of the proposed strategy.

基于CFD的某轻客中冷器性能三维、一维耦合分析

文章利用商用三维计算流体力学(CFD)软件和一维仿真软件相结合,对某型车机舱内外流场进行模拟分析,得到中冷器周围流场特性,并对流场进行优化,提升通过中冷器的风量。然后通过一维软件对中冷器在整车上的性能进行分析并与实验数据进行对比,结果表明,分析结果与实验结果吻合度较高。

基于地震反演技术的地应力建模方法在江汉新沟嘴组页岩油中的应用

江汉盆地新沟嘴组页岩油地质评价资源量为3.6×108 t,具有良好的勘探潜力,其中地质评价Ⅰ类有利区陈沱口凹陷有多口井在新沟嘴组新下段Ⅱ油组泥质白云岩中获得油流。由于页岩油井通常采用“水平井+分段压裂”工艺实现经济开采,因而地应力研究对该区水平井储层压裂改造具有重要的意义。三维地应力建模研究的核心问题在于提升井间地应力预测效果,传统的有限元方法由于方法本身的限制,井间预测效果较差,有必要利用地震资料反演技术来提升井间地应力预测的效果。针对该区页岩层矿物组分多、局部发育硫酸盐岩、地应力条件复杂的问题,首先对新沟嘴组页岩层开展基于实验室测量值约束的精细测井评价,其结果与岩心全岩X衍射测量结果吻合;在此基础上,选择自相容近似地震岩石物理建模流程,对目标层的弹性参数进行了正演模拟,正演结果与实测曲线基本吻合。然后,基于地层压力、实验室测量的岩石力学性能参数和测井解释结果,依据不同岩性的动静态关系,采用有效应力比值和构造应变法计算井的地应力参数。最后运用基于地震叠前反演技术的三维地应力建模方法,使用与一维地质力学建模相同的相关性和参数约束,建立了新沟嘴组页岩油的三维地应力模型。与一维地质力学研究成果相比,该三维地应力模型提取的伪曲线与工区大部分井一维地应力结果基本吻合,验证了该方法在新沟嘴页岩油地应力评价中的适用性和准确性。

Ionic liquid engineering enabled in-plane orientated 1D perovskite nanorods for efficient mixed-dimensional perovskite photovoltaics

Mixed-dimensional engineering of perovskite material has been demonstrated as a facile and promising strategy to improve both photovoltaic performance and long-term stability of perovskite solar cells(PSCs).In this study,we report an in-plane preferred orientation of 1D perovskite induced by an ionic liquid(IL)of 1-(3-cyanopropyl)-3-methylimidazolium chloride(CPMIMCl)for the first time via sequential deposition approach,leading to a mixed dimensional perovskite thin films.The generated one-dimensional(1D)CPMIMPbI3 with in-plane orientation resides at the grain boundaries of three-dimensional(3D)perovskite can be appreciably observed from the morphology level,leading to creation of high-quality films with large grain size with more efficient defect passivation.Moreover,the dispersion of IL in the bulk phase of perovskite material allows for the formation of 1D perovskite for multiple level passivation to inhibit non-radiative recombination and optimize carrier transport.This IL engineering strategy not only yields a mixed-dimensional perovskite heterostructure with in-plane orientation 1D perovskite nano-rods but also significantly improves the opto-electronic property with suppressed trap states.As a result,the CPMIMCl-treated PSCs show an enhanced photovoltaic performance with a champion power conversion efficiency(PCE)up to 24.13%.More importantly,benefiting from the hydrophobicity of formed 1D perovskite and defects suppression,the corresponding PSC demonstrates an excellent longterm stability and maintain 97.1%of its pristine PCE at 25C under 50%RH condition over 1000 h.This research provides an innovative perspective for employing the low dimensional engineering to optimize the performance and stability of photovoltaic devices.