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.

lncRNA HOTAIR通过miR-519d-3p/CCND1分子轴促进乳腺癌SKBR3细胞的恶性生物学行为

目的:探究lncRNA HOTAIR/miR-519d-3p/CCND1分子轴对乳腺癌细胞增殖和转移的影响及其可能机制。方法:收集2017年3月至2019年2月南昌市第三医院乳腺外科手术切除的乳腺癌患者的乳腺癌组织及配对癌旁组织各50例,qPCR检测癌及癌旁组织中HOTAIR的表达水平,乳腺正常上皮细胞及乳腺癌细胞系中HOTAIR和miR-519d-3p的表达水平。将乳腺癌SKBR3细胞分为NC组、si-HOTAIR组、miR-519d-3p mimics组,miR-519d-3p mimics+pcHOTAIR组、miR-519d-3p mimics+pcCCND1组和si-HOTAIR+pcCCND1组,CCK-8法检测各组SKBR3细胞增殖能力、Transwell检测细胞侵袭和迁移能力、Western blotting检测SKBR3细胞中E-cadherin、N-cadherin、Vimentin以及CCND1表达水平。双荧光素酶报告基因检测HOTAIR和miR-519d-3p以及miR-519d-3p和CCND1的靶向关系。结果:HOTAIR在癌组织以及乳腺癌细胞系中呈高表达,且在SKBR3细胞系中表达最高。敲降HOTAIR可显著抑制SKBR3细胞增殖、侵袭和迁移,并显著增加E-cadherin的表达水平、降低N-cadherin和Vimentin的表达水平(均P<0.05)。双荧光素酶报告基因检测显示,HOTAIR靶向下调miR-519d-3p的表达,miR-519d-3p靶向下调CCND1的表达。敲降HOTAIR可增强miR-519d-3p对CCND1的下调作用,抑制SKBR3细胞EMT、增殖、侵袭和迁移能力(均P<0.05)。结论:敲降HOTAIR可抑制SKBR3细胞增殖和转移,其机制是通过调控miR-519d-3p/CCND1分子轴实现的。

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。

Pressure Effects on Spectra of Tunable Laser Crystal GSGG:Cr3+ III: Pressure-Induced Shift of R1 Line at 70 K

By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R1 line of GSGG:Cr3+ at 70 K have been calculated, respectively. Their physical origins have been revealed. It is found that the admixture of and base-wavefunctions in the wavefunctions of R1 level of GSGG:Cr3+ at 70 K is remarkable under the normal pressure, and the degree of the admixture rapidly decreases with increasing pressure. The change of the degree of the admixture with the pressure plays a key role for not only the pure electronic PS of R1 line but also the PS of R1 line due to EPI. The detailed calculations and analyses show that the pressure-dependent behaviors of the pure electronic PS of R1 line and the PS of R1 line due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R1 line, which has satisfactorily explained the experimental data (including a reversal of PS of R1 line). In contributions to PS of R1 line due to EPI at 70 K, the temperature-independent contribution is much larger than the temperature-dependent contribution. The former results from the interaction between the zero-point vibration of the lattice and localized electronic state.

Pressure Effects on Spectra of Tunable Laser Crystal GSGG： Cr^3＋ IV： Pressure—Induced Shifts of R1 Line, R2 Line, and U Band at 300 K

By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R1 line, R2 line, and U band of GSGG:Cr3+ at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-degree of and base-wavefunctions in the wavefunctions of R1 level of GSGG:Cr3+ at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R1 line and R2 line but also the PS of R1 line and R2 line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R1 line (or R2 line) and the PS of R1 line (or R2 line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R1 line (or R2 line). In the range of about 15 kbar ~ 45 kbar, the mergence and/or order-reversal between levels and levels take place, which cause the fluctuation of the rate of PS for with pressure. At 300 K, both the temperature-dependent contribution to R1 line (or R2 line or U band) from EPI and the temperature-independent one are important.

基于“一维系统+三维CFD”耦合方法的快堆非能动余热排出系统自然循环特性的数值模拟

池式快堆采用了新型非能动堆内直接余热排出(DRACS)方式,提升了快堆的安全性。目前针对池式快堆自然循环开展的数值模拟研究中,系统程序难以准确预测池内复杂自然循环路径,难以准确模拟池内三维热工水力现象,如果采用三维CFD计算建模及网格划分难度较高,且所需计算资源较大。为此本文开发了“一维系统+三维CFD”耦合方法,用于快堆非能动余热排出系统自然循环特性计算分析。利用日本大型钠回路实验台架(PLANDTL)DRACS自然循环模式对该耦合方法进行验证,稳态工况关键位置参数相对误差小于3%,瞬态工况关键位置参数与实验值变化趋势吻合较好,相对误差小于10%,验证了该耦合方法的适用性和准确性。利用该耦合方法,开展了中国实验快堆(CEFR)自然循环及余热排出特性计算分析,识别了池内自然循环流动路径,揭示了池内温度分层以及盒间流现象。本文方法可为大型钠冷快堆自然循环三维瞬态特性分析提供重要数值方法。

SIMULATION OF HYDRAULIC TRANSIENTS IN HYDROPOWER SYSTEMS USING THE 1-D-3-D COUPLING APPROACH

Although the hydraulic transients in pipe systems are usually simulated by using a one-dimensional （l-D） approach, local three-dimensional （3-D） simulations are necessary because of obvious 3-D flow features in some local regions of the hydropower systems. This paper combines the 1-D method with a 3-D fluid flow model to simulate the Multi-Dimensional （MD） hydraulic transients in hydropower systems and proposes two methods for modeling the compressible water with the correct wave speed, and two strategies for efficiently coupling the 1-D and 3-D computational domains. The methods are validated by simulating the water hammer waves and the oscillations of the water level in a surge tank, and comparing the results ~with the 1-D solution data. An MD study is conducted for the transient flows in a realistic water conveying system that consists of a draft tube, a tailrace surge tank and a tailrace tunnel. It is shown that the 1-D-3-D coupling approach is an efficient and promising way to simulate the hydraulic transients in the hydropower systems in which the interactions between 1-D hydraulic fluctuations of the pipeline systems and the local 3-D flow patterns should be considered.

Transient air-water flow patterns in the vent tube in hydropower tailrace system simulated by 1-D-3-D coupling method

The vent tube is commonly used for the water hammer protection in the hydropower tailrace system. In transient processes, with air entering and exiting the vent tube, one sees complex hydraulic phenomena, which threaten the station＇s safe operation. It is necessary to investigate the transient mechanisms in the tailrace system with vent tube. In this paper, a 3-D, two-phase numerical model of a vent tube on the connection of the tailrace tunnel and the diversion tunnel, is developed based on the FLUENT with the volume of fluid（VOF） algorithm to investigate the transient air-water flow patterns and the complex hydraulic phenomena in the vent tube of the tailrace system. A 1-D and 3-D unidirectional adjacent coupling（1-D-3-D-UAC） approach with a linear interpolation method is adopted to adjust the timesteps between the 1-D model and the 3-D model on the tunnel inlet and outlet boundaries through the user defined function（UDF）, to transmit the data from the 1-D model to the 3-D model. The model is verified by comparing the results obtained by using the 1-D model alone and from the experiments in literature. The transient flow processes under the full load rejection consist of four stages： the water level dropping stage, the air entering stage, the air pocket collapsing stage, and the air exiting stage. Detailed hydraulic phenomena in the air pocket collapsing process are also discussed.

17aα—D-高炔雌二醇-3-乙酯联合γ射线照射对不同品系小鼠的抑瘤作用

目的对比观察17a α—D-高炔雌二醇-3-乙酯（DHEA）对不同品系小鼠肺腺癌的抑瘤作用及探讨合用^137Cs γ射线照射是否具有抑瘤增效作用。方法将LA795肺腺癌细胞用生理盐水稀释为浓度约3．5×10^7／ml瘤细胞，接种于近交系IRM-1和IRM-2小鼠腋下，0．2ml／只，24h后分别将IRM-1和IRM-2荷瘤小鼠随机分为8组：对照组、单照组、DHEA（低、中、高剂量）组和DHEA（低、中、高剂量）联合照射组。DHEA组与DHEA联合照射组采取腹腔给药，每日1次，连续7d。其中，DHEA联合照射组于给药的第4日进行全身1Gy照射，每日1次，连续5d。观察DHEA联合γ射线照射对小鼠肺腺癌的抑瘤效果及对相关免疫学指标的影响。结果DHEA低、中、高剂量组对IRM-1荷瘤小鼠的抑瘤率分别为38．05％、49．33％和48．18％，与对照组比较差异有统计学意义（担3．417，4．929和4．889，P均〈0．01），联合^137Cs γ射线照射后的抑瘤率分别为56．98％、64．44％和62．72％，与对照组比较差异有统计学意义（t=5．475，5．770和6．165，P均〈0．01）。DHEA低、中、高剂量组对IRM-2小鼠的抑瘤率分别为42．73％、70．91％和67．73％，其中，中、高剂量组与对照组比较差异有统计学意义（t=3．239和3．062，P均〈0．01），联合^137Cs γ射线照射后的抑瘤率分别为63．63％、75．00％和68．64％，与对照组比较差异有统计学意义（t=2．834，3．426和3．156，P分别为〈0．05，〈0．01和〈0．01）。结论DHEA对不同品系小鼠肺腺癌细胞均有抑制作用，联合γ射线照射后的抑瘤疗效比单纯DHEA组更为明显。

Simulation of Unsteady State Performance of a Secondary Air System by the 1D-3D-Structure Coupled Method

This paper describes the calculation method for unsteady state conditions in the secondary air systems in gas turbines. The 1D-3D-Structure coupled method was applied. A 1D code was used to model the standard components that have typical geometric characteristics. Their flow and heat transfer were described by empirical correlations based on experimental data or CFD calculations. A 3D code was used to model the non-standard components that cannot be described by typical geometric languages, while a finite element analysis was carried out to compute the structural deformation and heat conduction at certain important positions. These codes were coupled through their interfaces. Thus, the changes in heat transfer and structure and their interactions caused by exterior disturbances can be reflected. The results of the coupling method in an unsteady state showed an apparent deviation from the existing data, while the results in the steady state were highly consistent with the existing data. The difference in the results in the unsteady state was caused primarily by structural deformation that cannot be predicted by the 1D method. Thus, in order to obtain the unsteady state performance of a secondary air system more accurately and efficiently, the 1D-3D-Structure coupled method should be used.

An optimized time-adaptive aerothermal coupling calculation method for aerothermal analysis of disc cavity system

In order to further achieve the balance between the calculation accuracy and efficiency of the transient analysis of the aero-engine disc cavity system,an Optimized Time-adaptive Aerother-mal Coupling calculation(OTAC)method has been proposed.It combines one-dimensional tran-sient calculation of air system,Conventional Sequence Staggered(CSS)method,Time-adaptive Aerothermal Coupling calculation(TAC)method and differential evolution optimization algorithm to obtain an efficient and high-precision aerothermal coupling calculation method of air system.Considering both the heat conduction in the solid domain and the flow in the fluid domain as unsteady states in the OTAC,the interaction of fluid-solid information within a single coupling time step size was implemented based on the CSS method.Furthermore,the coupling time step size was automatically adjusted with the number of iterations by using the Proportional-Integral-Deri vative(PID)controller.Results show that when compared with the traditional loosely coupling method with a fixed time step size,the computational accuracy and efficiency of the OTAC method are improved by 8.9%and 30%,respectively.Compared with the tight coupling calculation,the OTAC method can achieve a speedup of 1 to 2 orders of magnitude,while the calculation error is maintained within 6.1%.

基于1D-3D耦合方法的变顶高尾水洞明满混合流的研究

水电站过渡过程中变顶高尾水洞的非恒定流通常为明满混合流,其流态较为复杂,三维流动现象较为明显。对明满混合流能否准确地模拟直接关系到机组的调节保证参数。为此本文采用1D-3D耦合方法对其进行数值模拟,并与传统的虚拟狭缝法模拟结果进行对比。由此,探讨两种方法在模拟明满混合流分界面波动过程的差异以及对尾水管最小动水压力的影响。结果表明:虚拟狭缝法存在较明显的缺陷,需要做出相应的改进。

地表河网-地下水流系统耦合模拟Ⅰ:模型

本文通过采用联立求解地表河流一维明渠非恒定渐变流与地下水拟三维非稳定流运动方程的技术路线,提出了地表河网与地下水流耦合模拟算法。该算法中地表河网流动分别由质量和动量守恒定律而建立的连续性方程和运动方程所组成;地下水流采用多层"拟三维"非稳定流模型,通过彼此间的水力联系,建立了地表河网-地下水流耦合模拟评价模型,该模型可用于地表水与地下水转化关系较为密切地区的水资源综合评价预测中。

珠江三角洲一维河网与三维河口耦合水质模型模拟与验证

在一维与三维耦合水动力、悬沙模型的基础上,构建了珠江三角洲一维与三维耦合水质模型。模型中包括浮游植物-氮-磷-碳-溶解氧循环,并考虑颗粒物在底泥与水体界面的再悬浮过程。选择了三个代表性时段(1999年1月、1999年7月与2000年)进行水质模拟,并采用相应水期的实测资料进行验证。结果表明,耦合水质模型计算效果良好,较好地再现了整个研究区域内各水质要素的时空分布规律,成功描述了珠江三角洲河网与河口区的动力与生物化学变化过程。

基于一三维耦合的装甲车辆冷却系统高原环境适应性研究

建立了车辆冷却系统CFD模型和一维性能仿真模型,采用一三维顺序耦合计算的方法,研究了高原环境对车辆冷却系统性能的影响.结果表明,随海拔的升高,流经冷却系统的空气质量流量下降相当明显,且4 500 m海拔下的冷却系统空气质量流量仅为海拔0 m下的65%.海拔在3 000 m以下时,冷却系统散热量下降不多;超过3 000 m后,系统散热量剧烈下降,4 500 m海拔下的散热量仅为平原下的82%左右.研究结果对于车辆冷却系统的高原适应性设计与改进具有指导意义.

基于一维/三维耦合仿真的工程机械冷却系统优化设计

本文针对一款设计中的工程机械冷却系统,建立了一维数值模型与三维CFD模型。通过一维/三维耦合计算,研究在散热器模块串联安置并留有间隙的情况下,部分空气绕过前排散热器流动对工程机械冷却系统换热性能造成的影响。将CFD计算结果的风速数据嵌入标准的一维数值模型,对一维仿真计算进行修正。修正后,前排低温油散热器尺寸需要增加约11.3%,经实验验证满足要求。一维/三维耦合仿真使冷却系统热管理仿真计算的精度得到提高,使一维仿真结果更加接近实际情况。

某四缸柴油机各缸EGR率均匀分配的优化

采用废气再循环(EGR)技术的多缸柴油机,EGR率在各缸的均匀分布能有效保证燃烧质量,优化排放。通过改进某四缸柴油机EGR出口管路的结构,建立进气管路的一维与三维模型,给出模拟仿真分析过程,运用一维整机性能分析软件GT-Power与三维CFD软件AVL Fire分别对新旧2种进气歧管进行1D-3D耦合分析,得出优化后管路EGR最大偏差率8.99%,明显小于原始管路44.79%的EGR最大偏差率,优化管路更有利于EGR率的均匀分配。

基于慢性病患者的中医生命质量评价量表、六维健康调查简表第一版和三水平五维健康量表结果比较研究

背景我国慢性病患者逐年增加,健康相关生命质量是评价慢性病预防和治疗效果的重要指标,选择合适的慢性病患者健康相关生命质量测量工具有重要意义。目的评估中医生命质量评价量表(CQ-11D)、六维健康调查简表第一版(SF-6Dv1)和三水平五维健康量表(EQ-5D-3L)测量慢性病患者健康效用值的效度、一致性和相关性,探索较适用于慢性病患者的量表。方法根据中国人口的性别及年龄比例进行配额抽样,2021年2—4月,在华北、东北、华东、华中、西南、西北及华南7个地理区域展开调查,每个分区选取2~6个具有代表性的省、自治区及直辖市(共28个),采用“面对面”调查的方式收集受访者的基本信息与患慢性病情况,并依次收集CQ-11D、SF-6Dv1和EQ-5D-3L的自报结果,从中筛选慢性病患者,对3个量表的效用值测量结果进行分析,采用Bland-Altman图和组内相关系数(ICC)分析3个量表的一致性和相关性,并使用Kruskal-Wallis H检验对性别和年龄进行单因素分析。结果研究共纳入692例慢性病患者,CQ-11D、SF-6Dv1和EQ-5D-3L测量总体慢性病患者的效用均值分别为(0.855±0.168)、(0.793±0.132)和(0.876±0.136)。患病人数前三的慢性病分别为高血压(n=275)、关节炎(n=128)和高脂血症(n=124)。直方图显示EQ-5D-3L具有明显的天花板效应,CQ-11D分布范围更广泛;Bland-Altman图显示3个量表间的一致性相对较好,95%一致性区间(LOA)内的点均在95%左右;CQ-11D与视觉模拟评分(VAS)的相关性最高(P<0.001),3个量表间的ICC范围为0.528~0.625,显示出中等水平的相关性(P<0.001),其中Bland-Altman图和ICC分析结果均显示SF-6Dv1与EQ-5D-3L的一致性最好。对3种不同慢性病的亚组分析结果与上述总样本结果相似。单因素分析结果显示,高血压、高脂血症患者中,男性患者3个量表的效用值均高于女性(P<0.05)。高脂血症患者中,3种量表测量效用值最小值均在≥60岁人群。结论在慢性病患者中,EQ-5D-3L的天花板效应较为明显。CQ-11D测量3种慢性病效用值范围分布较为广泛,并且未观察到天花板效应,同时与VAS的相关性最高,相对适合测量中国慢性病患者的健康相关生命质量。

整机起落架的半主动控制落震仿真分析

半主动控制技术在起落架上的应用局限于单起落架或磁流变式起落架,整机起落架的研究对半主动控制的实际应用更有价值。采用LMS Virtual.lab Motion建立整机虚拟模型,以单腔式油气缓冲器为研究对象,分析被动控制和半主动控制的力学模型,在AMESim中搭建油气式缓冲器仿真模型;基于模糊控制理论和变阻尼节流阀半主动控制原理,在MATLAB/Simulink中设计模糊控制器,将控制器模型集成到AMESim中实现对阻尼孔的实时控制;通过机械、液压、控制的3D-1D联合仿真分析被动控制和半主动控制下整机落震的仿真结果。结果表明:落震工况下,半主动控制响应速度快,前、主起落架的缓冲支柱垂向载荷峰值分别降低了20.5%和13.1%,缓冲效率高于被动控制;机身垂向加速度峰值降低了23.2%,并更快趋于稳定,提高了乘坐舒适性。

Multi-scale simulation model of air system based on cross-dimensional data transmission method

The Secondary Air System(SAS)plays an important role in the safe operation and performance of aeroengines.The traditional 1D-3D coupling method loses information when used for secondary air systems,which affects the calculation accuracy.In this paper,a Cross-dimensional Data Transmission method(CDT)from 3D to 1D is proposed by introducing flow field uniformity into the data transmission.First,a uniformity index was established to quantify the flow field parameter distribution characteristics,and a uniformity index prediction model based on the locally weighted regression method(Lowess)was established to quickly obtain the flow field information.Then,an information selection criterion in 3D to 1D data transmission was established based on the Spearman rank correlation coefficient between the uniformity index and the accuracy of coupling calculation,and the calculation method was automatically determined according to the established criterion.Finally,a modified function was obtained by fitting the ratio of the 3D mass-average parameters to the analytical solution,which are then used to modify the selected parameters at the 1D-3D interface.Taking a typical disk cavity air system as an example,the results show that the calculation accuracy of the CDT method is greatly improved by a relative 53.88%compared with the traditional 1D-3D coupling method.Furthermore,the CDT method achieves a speedup of 2 to 3 orders of magnitude compared to the 3D calculation.