局域共振型周期管路系统振动特性研究

管路系统广泛应用于船舶动力设备、空调通风管道等系统中，是振动传递的一个重要途径，控制管路的振动可有效抑制其对振动噪声的传递。声子晶体周期管路结构设计技术能有效减低管路系统的低频振动噪声。以一种局域共振型周期管路为研究对象，建立周期管路系统的仿真模型，分析局域振子宽度、外径和材料密度等参数对周期管路减振效果的影响规律，并通过试验进行验证。结果表明：局域振子的宽度和材料密度对管路系统减振效果影响明显，最高可降低7.8 dB；局域振子的外径对管路系统的振级落差影响较小。基于局域共振设计周期管路系统可为管路系统的减振设计提供新的思路。     

管路振动噪声对船舶总体声隐身特性的影响

船舶声隐身性能由其自身的噪声量级确定,而管路系统的噪声又是船舶噪声的重要组成部分,由于管路噪声有其自身的特点,因此对于船舶声隐身性能的影响也具有其特殊性。结合工程实践分析船舶管路振动噪声与船舶总体声隐身特性的关联关系,得出管路的水动力噪声是影响船舶声纳平台区自噪声的主要干扰源之一的结论。围绕管路水动力噪声的生成特点,提出几点工作建议供同行参考。     

通风空调系统再生噪声的识别与控制

在通风空调管路系统中，除了随气流传传播空气动力源的运转噪声外，还因工况参数的选择、管路走向的布置以及系统运行调试中各类因素的影响，对即使考虑过声学设计的管路系统仍有可能出现新的再生噪声源，从而使通风空调房间受到噪声干扰。本文基于对实际工程问题所作的调研和实践，着重分析了再生噪声源的产生机制和影响程度，并就可能采取相应的识别方法和控制措施进行了有益的探讨。其中的一些观点和结论，是作者在这方面问题研究的工作成果。实践表明，重视对再生噪声源的防治，还可在工程设计中取得较为显著的经济效益。     

舰船管路系统声振控制技术评述与声子晶体减振降噪应用探索

舰船管路系统的低频振动和噪声控制问题是当前舰船设计和制造中亟待解决的重难点问题和研究热点。浅析了舰船管路系统振动与噪声产生的原因,综述了国内外管路系统减振降噪治理技术,指出当前振动和噪声控制技术中存在的瓶颈问题,结合近年来凝聚态物理领域新兴的声子晶体减振降噪研究,提出利用声子晶体周期结构设计技术解决舰船管路系统的低频减振降噪问题,并对国内外声子晶体理论在管路系统的减振降噪应用探索进行了概述,最后给出将声子晶体引入舰船管路系统低频减振降噪仍需深入研究和探讨的几个方面问题。     

C620—1B型车床噪声的治理

C620—1B型普通车床面广量大,至今仍在各行业中广泛应用。但该机床因结构和齿轮制造误差等因素,致使噪声很大。我厂有台72年的产品噪声竟高达到91分贝(A),治理后,使噪声下降到82分贝(A),取得了明显的效果。     

通海系统管路阻尼处理降噪技术研究

机械设备通过管路系统产生的辐射噪声是合成潜艇总噪声的重要来源之一,随着浮筏装置的广泛应用,机械设备通过机脚、基座引起的振动噪声已得到较好的控制,同时原来被掩盖的管路系统引起的振动噪声逐渐突出。通过在管壁外敷设阻尼结构吸收并耗散振动能量是降低管路系统振动噪声的有效方法之一。通过对通海系统管路敷设阻尼胶带的插入损失进行了理论分析和试验研究,结果表明,管路表面敷设阻尼胶带能有效降低沿管路传递的振动,对于降低沿管路传播的振动噪声从而增强舰船的隐蔽性具有重要意义。     

船用低噪声布风器设计与声学性能分析

在船舶与海洋平台中,空调管路系统噪声是舱室噪声的主要来源之一,风机与管路元件流动噪声通过管路系统与管口传递至舱室,布风器处于管路系统的末端,是连接管路系统与舱室之间的重要元件,在空调系统噪声控制中起重要作用.针对管路系统管口辐射噪声,在兼顾气动性能及声学效果基础上,提出新型低噪声布风器结构形式,采用数值模拟方法开展布风...     

船台生产作业噪声治理及声屏障降噪效果预测

针对造船厂船台生产作业噪声治理及降噪效果预测难的问题,提出船台噪声的治理方法。以某造船厂船台噪声治理为例,结合某造船厂船台噪声治理实例,提出船台噪声的治理方法,并针对其噪声特点,对噪声源进行建模,预测了主要治理措施的降噪效果。结果表明,造船厂船台生产作业噪声需从声源、声传播途径及生产作业管理等多方面进行综合治理;除降噪效果外,声屏障的设置还需考虑施工可行性、社会因素以及经济性等实际情况;对于船台生产作业噪声等分布范围广、密度大、垂向位置高的声源的模拟预测,需根据声源实际工况进行针对性建模。研究可为船台生产作业噪声等类似噪声源的噪声治理和预测提供参考。     

大推力氢氧火箭发动机试验噪声治理技术概述

在大推力氢氧火箭发动机试验中,噪声问题越来越突出,有必要对其采取噪声治理措施。总结大推力氢氧火箭发动机噪声治理的难点和影响大推力氢氧火箭发动机噪声治理的因素,介绍大推力氢氧火箭发动机高空模拟试验和地面试验的降噪方法,并对喷水降噪后进一步的噪声治理措施给出建议。     

单联和双联液压管路系统流固耦合振动特性分析

飞机液压管路常用于发动机的燃油与滑油输送，由不同种类的卡箍将其固定，组成液压管路系统。根据管路形状不同，连接形式多样，常见的包括单联液压管路系统和双联液压管路系统。为避免复杂工作环境下因流固耦合振动而导致管路系统出现振动失效等问题，以典型的单联和双联液压管路系统为对象，基于管路本体的Euler-Bernoulli梁假设和黏弹性材料假设，采用牛顿法分别对管路和管路中的流体进行受力分析，再通过加减消元推导出管路系统的运动微分方程。然后，进行无量纲化处理，依据管路两端一般支承的边界条件求解出管路系统模态函数和频率方程，并通过Galerkin法将单联和双联管路系统的运动微分方程在模态空间内展开，进行振动特性的计算分析，获得内部液压油的流速、压力以及质量比对液压管路系统流固耦合振动特性的影响。     

Moveable social manufacturing: Making for shared peace and prosperity in fragile regions

It has been argued that local people making what they need with moveable factories can improve potential for peace and prosperity. In this paper, moveable social manufacturing is described in the context of fragile regions in Somalia. Moveable manufacturing involves means of production that are designed and fabricated to be moveable. They can be used to carry out a wide range of production work from agricultural processing to manufacturing complicated mechatronic assemblies. Moveable factories have received little attention in the literature, but have already started to be used in challenging environments from Afghanistan to Uganda. Social manufacturing involves people sharing the efforts, means and rewards of production. The reported research involved literature review and field study in Somalia. Study findings indicate that moveable social manufacturing is relevant to fragile regions of Somalia. In particular, study findings indicate that the best opportunities for moveable social manufacturing may be scaling up artisanal production, while seeking to add market value through focusing on brand authenticity and integrity. Moreover, moveable social manufacturing has potential to contribute towards reducing the socio-economic polarization, which has developed in many emerging economies.     

冷冻食品加工企业能效评价

目前我国综合食品加工企业都使用单化产值的能耗量或能耗费用水衡量能耗的程度,山于这种指标没有反映出使用水平、营业水平和质量水平对企业、能效的影响,所以在企业之间能效比较时难以作出正确评价。文章以实例列举出国内外有代表性的大型综合食乩加工食品企业的能耗现状进行对比;分析了日前企业使用的能耗评价指标在横向比较、评价时出现错误的原因：提出了可反映使用水半、营业水半和质量水平新的能效评价方法,对国内六家有代表性的食品企业进行能效评价,结果移示食业之间能效芹芹十分显著,节能降牦提高能效成为食品企业迫切需要解决的问题。     

A hybrid Tabu sample-sort simulated annealing approach for solving distributed scheduling problem

The distributed scheduling problem has been considered as the allocation of a task to various machines in such a way that these machines are situated in different factories and these factories are geographically distributed. Therefore distributed scheduling has fulfilled various objectives, such as allocation of task to the factories and machines in such a manner that it can utilise the maximum resources. The objective of this paper is to minimise the makespan in each factory by considering the transportation time between the factories. In this paper, to address such a problem of scheduling in distributed manufacturing environment, a novel algorithm has been developed. The proposed algorithm gleans the ideas both from Tabu search and sample sort simulated annealing. A new algorithm known as hybrid Tabu sample-sort simulated annealing (HTSSA) has been developed and it has been tested on the numerical example. To reveal the supremacy of the proposed algorithm over simple SSA and Tabu search, more computational experiments have also been performed on 10 randomly generated datasets.     

Comments on “A note on multigoal heuristic for facilities design problems: MUGHAL”

As manufacturers continue to automate their factories, they discover that existing cost measures should be updated. Much of the existing literature has discussed the ‘why's’ but there is little about the ‘how's’. This paper expands the cost concept to include quality and flexibility because they are critical factors for performance evaluation and project justification of advanced manufacturing systems. Then, a quantitative method of estimating the cost elements is illustrated. Finally, various approaches to collecting parametric values of the cost model and applications of the cost model are presented.     

Moveable factories: How to enable sustainable widespread manufacturing by local people in regions without manufacturing skills and infrastructure

Moveable factories enable high performance manufacturing. They carry their own power generation and are built to cover rough terrain. Hence, they have potential to enable more widespread modern manufacturing. In this paper, findings are reported from a study addressing two research questions. First, what goods should be produced by local people in regions without manufacturing skills and infrastructure? Second, how can lack of manufacturing skills and infrastructure be overcome? The study comprised literature review, semi-structured interviews, and structured questionnaire. Research participants are from Horn of Africa and from West Africa. All the goods that research participants considered to have potential for profitable production can be made with types of moveable factories that are available. Lack of local skills can be overcome through application of task design using proven techniques. In addition, techniques for designing capable production processes are applicable to moveable production. Established techniques for optimizing mix of production facilities, locations, and routes are also applicable. The robust mobility of moveable factories, and application of proven techniques, reduces the need for manufacturing infrastructure. Moveable factories are relevant to literature and debate concerning re-shoring/on-shoring/right-shoring/best-shoring manufacturing, sustainable manufacturing, advanced manufacturing, and distributed manufacturing. The relevance of moveable factories to these topics is analysed in terms of Resource-Based Theory, Knowledge-Based View, and Transaction Cost Economics.     

西北地区制药厂洁净空调特点分析及选用

针对西北地区药厂如何选用洁净空调机组，介绍笔者在几家制药厂参观学习过程中总结的关于西北地区洁净空调特点、空调机组设计及选用的一些想法和经验，供当地其他药厂及相关的行业设计时参考。     

重大环境污染事故风险模糊排序方法研究

据工厂重大环境污染事故风险评价呈多指标多层次结构, 且风险性排序具有相对性和模糊性的特点, 运用模糊集理论中的权距离和隶属度概念, 并将最小二乘法加以拓展, 提出能够有效解决此类多指标多层次排序或优选问题的模糊排序方法。用于对大连市4家重点工厂的事故风险性进行评价和排序, 评价结果合理、准确。     

Price negotiation for capacity sharing in a two-factory environment using genetic algorithm

Uncertain and lumpy demand forces capacity planners to maximize the profit of individual factory by simultaneously taking advantage of outsourcing to and/or being outsourced from its supply chain and even competitors. This study develops a resource-planning model of a large manufacturer with two profit-centered factories. The proposed model enables a collaborative integration for resource and demand sharing which is highly attractive to the high-tech industries against the challenges of short product life cycle, intensive capital investment and decreasing marginal profit. Each of the individual factories applies an economic resource-planning model and a genetic algorithm to improve its objective while purchasing extra capacity requirement from its peer factory or selling extra capacity of resources to the others through a negotiation algorithm. This study makes a contribution in successfully building a mutual negotiation model for a set of customer tasks to be realized by the negotiating parties, each with private information regarding company objectives, cost and price. Experimental results reveal that near-optimal solutions for both of the isolated (a single factory) and negotiation-based (between two factories) environments are obtained.     

太阳能溶液除湿空调系统在工厂的应用分析

介绍了基于太阳能集热、溶液除湿和水蒸发冷却技术结合的太阳能溶液除湿空调的原理；提出了一种太阳能溶液除湿空调系统，并对该系统在工厂的应用进行了分析；认为太阳能溶液除湿空调有着独特的优点：环保、节能、可方便的储存能量，可应用于传统空调所不能胜任的工厂和车间，有着较大的经济效益和社会意义。     

铝电解电容器用电子铝箔的性能分析与比较

利用原子吸收光谱仪(AAS)、电子扫描电镜(SEM)、电子背散射技术(EBSD)、电化学工作站等方法对不同厂家生产的铝电解电容器用电子铝箔各方面的性能进行比较和分析。结果表明,国产铝箔在微量元素设计和杂质控制,立方织构控制方面已达到国外同类产品的先进技术水平,但表面加工质量,氧化层均一性和微量元素的分布控制方面与国外存在差距。