Computational fluid dynamics-based multiobjective optimization of a surface combatant using a global optimization method

The main objective of this article is to describe the development of two advanced multiobjective optimization methods based on derivative-free techniques and complex computational fluid dynamics (CFD) analysis. Alternatives for the geometry and mesh manipulation techniques are also described. Emphasis is on advanced strategies for the use of computer resource-intensive CFD solvers in the optimization process: indeed, two up-to-date free surface-fitting Reynolds-averaged Navier-Stokes equation solvers are used as analysis tools for the evaluation of the objective function and functional constraints. The two optimization methods are realized and demonstrated on a real design problem: the optimization of the entire hull form of a surface combatant, the David Taylor Model Basin—Model 5415. Realistic functional and geometrical constraints for preventing unfeasible results and to get a final meaningful design are enforced and discussed. Finally, a recently proposed verification and validation methodology is applied to assess uncertainties and errors in simulation-based optimization, based on the differences between the numerically predicted improvement of the objective function and the actual improvement measured in a dedicated experimental campaign. The optimized model demonstrates improved characteristics beyond the numerical and experimental uncertainty, confirming the validity of the simulation-based design frameworks.     

粒子群优化算法在舰船维修费用分配中的应用

将舰船维修费用按照维修计划结构进行分解，通过回归分析方法，建立舰船维修总体效益与各项费用比例之间的分配优化模型，利用粒子群优化算法对模型最优化求解，计算实例具有较好的效果。     

基于等强度板格稳定的船体结构优化设计研究

以一艘110 m江海直达散货船为研究对象,通过全船有限元直接计算,对货舱区各主要构件的板厚进行优化,使船中0.6 L(即 0.2 L～0.8 L)范围内构件的屈服强度、屈曲强度都在IACS<散货船共同结构规范>规定的许用标准之内(或不超过许用标准5%),并且没有较大富余(至少有一种强度余量在±5%以 内).在参考其他优化算法的基础上,推出了适合文中模型的算法,通过计算证明该算法是可行的,收敛速度也比较快.     

基于粒子群优化算法的二阶系统解耦

从数值计算的角度出发研究了二阶系统的解耦问题,通过保持Lancaster结构将二阶系统的解耦问题转化为非线性约束的最优化求解问题.并利用粒子群优化算法求解此约束优化问题,直接给出非奇异的保结构解耦变换.利用Matlab编写程序实现此算法,数值实验结果表明在设定的迭代次数和精度内,此方法确实能实现原始系统的近似解耦.     

跨境供应链网络海外仓的鲁棒性选址模型及算法

新经济形态下，全球政治、经济形势瞬息万变，多种人为和自然因素导致商业供应链的生存环境日益严峻. 跨境供应链网络作为典型的时效性和运营环境等都具有极大不确定性的复杂网络，研究其鲁棒性问题具有一定的理论意义和实际应用场景. 首先阐明了跨境供应链网络的内涵，认为海外仓的选址优化是控制网络鲁棒性的重要手段；随后基于最小最大后悔值构建了海外仓的鲁棒性选址模型，利用情景松弛算法对模型进行求解. 算例分析结果证明，所构建的海外仓鲁棒性选址模型及算法适用于跨境供应链网络情景.     

MIPX涡轮增压系统优化研究

对8缸柴油机可能的发火顺序，给出了可用的MIXPC系统排气支管分支，并就MIXPC系统排气管系结构参数优化作了研究，提出了设计的基本原则。用FVM-TVD方法，分别对不同的机型进行了MIXPC系统的结构设计和性能模拟研究，得出了在8缸上采用MIXPC系统的一些普遍规律，并就不同缸数的柴油机进行系列化生产提出了设计方法。     

Superpave技术应用于醴茶高速公路沥青路面的可行性分析

在介绍Superpave技术和分析马歇尔设计方法存在问题的基础上,分析了Superpave技术应用醴茶高速公路沥青路面的可行性。应用Superpave理念对醴茶高速路面结构进行了优化,对比了优化方案的经济性,同时对Superpave的施工要点进行分析,以保证Superpave技术在施工中能够得到良好实现。     

朔黄铁路调度优化系统研究

为提高轴重300 k N以上重载铁路运输效率,建立基于车-地连续通信的调度优化系统,通过对历史运行数据进行充分的分析计算,得出优化的列车运行计划,并实时监督列车的运行状况,优化行车密度,实时调整运行计划,从而优化列车运行策略,提高效益。     

多换乘点响应型接驳公交运行线路的协调优化

为尽量降低响应型接驳公交系统的运行费用，提出多换乘点间运行线路协调设计的构想。针对同时包含预约需求和实时需求的混合需求，构建多换乘点响应型接驳公交系统运行线路的2阶段协调优化方法，并设计优化流程。第1阶段仅考虑预约需求，首先将预约乘客按有/无特定换乘点要求进行分类，在此基础上构建预约需求下多换乘点多车辆运行线路的协调优化模型。在协调优化模型中，优化目标是由乘客时间费用、车辆运行费用、以及惩罚费用所构成的系统总成本最小；乘客时间费用包括乘客候车时间的惩罚费用、车内乘客在需求点的等待时间费用以及乘客车上时间的惩罚费用3个部分；车辆运行费用包括车辆启动费用、路段行驶费用、需求点的停靠费用、车辆早到引起的等待费用4个部分；考虑的约束条件包括乘客候车和车上的软时间窗、乘客换乘点要求、车辆容量、车辆出行时长等。第2阶段根据规则判断是否响应实时需求，并根据响应情况重新优化后续各班次的运行线路。针对第1阶段模型，基于模拟退火算法设计求解算法。研究表明：在预约需求或混合需求条件下，与各换乘点运行线路独自优化相比，协调优化方法均能显著降低运送全部响应乘客所需的平均运行距离和平均总成本；仅有预约需求时分别降低5.4%、19.8%，新增实时需求后分别减少1.4%、21.7%；与固定发车间隔相比，分时段调整发车间隔，也能有效降低运送全部响应乘客所需的平均运行距离和平均总成本，仅有预约需求时分别降低18.2%、17.2%，新增实时需求后分别减少19.97%、25.06%，说明多换乘点间车辆路径的协调运行是提升响应型接驳公交运行效率的有效途径。     

An optimization model of energy and transportation systems: Assessing the high-speed rail impacts in the United States

This paper presents a long-term investment planning model that co-optimizes infrastructure investments and operations across transportation and electric infrastructure systems for meeting the energy and transportation needs in the United States. The developed passenger transportation model is integrated within the modeling framework of a National Long-term Energy and Transportation Planning (NETPLAN) software, and the model is applied to investigate the impact of high-speed rail (HSR) investments on interstate passenger transportation portfolio, fuel and electricity consumption, and 40-year cost and carbon dioxide (CO₂) emissions. The results show that there are feasible scenarios under which significant HSR penetration can be achieved, leading to reasonable decrease in national long-term CO₂ emissions and costs. At higher HSR penetration of approximately 30% relative to no HSR in the portfolio promises a 40-year cost savings of up to $0.63 T, gasoline and jet fuel consumption reduction of up to 34% for interstate passenger trips, CO₂ emissions reduction by about 0.8 billion short tons, and increased resilience against petroleum price shocks. Additionally, sensitivity studies with respect to light-duty vehicle mode share reveal that in order to realize such long-term cost and emission benefits, a change in the passenger mode choice is essential to ensure higher ridership for HSR.