发射过程中导弹喷管降载方法研究

发射过程中工质气体从侧向进入发射筒作用在导弹底部,导弹发动机喷管上将承受较大载荷,针对该问题建立了发射筒底部三维非稳态流场的数值模拟方法,并利用试验数据对该方法进行了校验。数值模拟结果表明,发射用工质气体近乎集中的作用到喷管特定区域是导致喷管载荷较大的主要原因。本文提出了一种能够改善发射筒底部流场结构、降低喷管受力的降载装置。进一步的数值模拟结果表明降载装置可以使喷管所受的最大总力矩下降26%,试验验证结果表明所提出的改进措施能够有效降低喷管所受载荷。     

潜艇舱室气体成分集中监测技术

本文介绍了国内外潜艇气体成分监测技术的发展状况，分析了主要有害气体监测的必要性，提出了需要连续监测的气体组分，介绍了采用成熟的气体敏感元件对主要气体组分进行连续监测的技术途径。     

涡轮增压柴油机排气系统的最优化

本文提出广义一维非定常流动计算模型,以计算排气管系中的气体流动。该模型考虑了分支质量添加的效应,使多缸机的计算得以简化。应用热力学第二定律对排气能量传递和转化进行分析,提出以(火用)差函数作为排气有用能的评价参数。最后建立了排气管系优化模型,以排气有用能传递效率为优化目标,利用工作过程计算得出了目标函数和结构参数之间的离散型函数关系,进行参数寻优。文中还介绍了根据以上方法进行结构优化设计所得到的试验结果。     

一种同轴式减压器的试验研究

本文提出了一种新型减压器结构—同轴式结构,并建立了同轴式减压器试验平台,进行了动态试验。试验结果表明:本文提出的同轴式减压器结构紧凑、调节灵活、具有±2.0%的调节精度,满足某装置对原料气体的大流量快速调节要求。同时验证了这种实验方法的可行性,对今后同类减压器的设计和试验具有一定的指导作用。     

国内首艘LNG船完成气体试航

3月10日，由沪东中华造船（集团）有限公司承建的国内首艘LNG船锅炉烧LNG无人机舱试验完成，这标志着该船气体试航成功。据介绍，锅炉烧LNG无人机舱试验项目是该船气体试航的关键环节，该试验的成功，宣告了该船机舱动力系统和货舱低温液货系统成功接合，且达到了完全自；动调节状态，也意味着我国首艘LNG船最后一道技术难关被攻克。     

排气管系中广义一维非定常流动的数值解

本文提出广义一维非定常流动的模型,用以计算内燃机进、排气管中气体的流动。文中叙述了该模型的控制体基本方程,引入特征线的概念,导出了相应的特征方程和相容性方程,并给出了有限差分网络的数值解。 文中还给出了MPC增压系统的计算实例。计算结果为试验所证实。最后给出了排气有用能动态传递过程的计算结果。     

潜艇肼吹除技术研究

国内外潜艇专家认为肼快速催化分解产生大量气体，是解决潜艇大深度应急吹除的有效技术途径。本文介绍了潜艇肼吹除技术研究和原理样机的设计及试验，其研究结果表明，采用肼分解技术可以解决潜艇大深度下应急吹除的难题。     

新型气体灭火剂探讨

本文论述了近年来国际上研制新型灭火剂的情况及其性能，通过综合比较，提出优选ＦＭ－２００作为较好的，能满足各方要求的新型灭火剂，并介绍了ＦＭ－２００气体灭火剂的灭火效能试验及气体浓度测量情况。     

计算流体动力学耐波性分析与试验结果的比较

介绍计算方法近年来的发成果如何应用于船模水池的耐波性试验分析。在某一问题的分析中，数值法能用于三个不同的阶段。首先，它能用来迅速作答并给问题定位。其次，它也能用来解释试验结果，并针这些结果用在某一模型中，最后进行优化。数值法对于准备试验和确定试验装置也是十分有用的。对船模试验水池可利用或正在开发的数值法的简要调查，表明了此工具在耐波性中所期望的性能，并给出选择不同方法的评价：频域，时域中的线性分析，自由表面的非线性描述以及特定的开发。计算流体动力学技术的某些应用的例子，为试验给出了几种船的转移函数分析，横摇稳性分析和造波系统的定义。     

变深度发射和能量可调发射动力系统

本文从筒内弹道方程出发，论述了潜地导弹变深度发射的关键参数是导弹的出筒速度Ｖｋ。对于出筒速度要求较宽的导弹，固定能量发射动力系统也可实现变深度发射；而对于出筒速度要求较严的导弹，固定能量发射动力系统则只能用于定深度发射，要实现变深度发射只有采用能量可调发射动力系统。理论分析表明，调节发射系统的能量可以从调节燃气生长量ωｒ、筒内温度Ｔ（ｌ）和喷水量ωｋ来实现。对此提出了相应的技术途径。通过多种技术途径分析，在变深度发射过程中要实现能量可调发射动力系统的技术途径，只有通过调节冷却器的喷水量才是可行的。对冷却器喷水量计算公式的分析表明，调节喷水量主要是调节喷水孔。根据此结论，本文介绍了两位级和多位级水冷却器能量可调发射动力系统的几种方案，供实际工程应用中参考。     

扭王字块在山区河流航道整治中的应用

介绍当前整治建筑物的主要结构形式和材料,分析川江航道整治建筑物水毁形式及原因,在此基础上,依托长江干线叙泸段(宜宾—泸州)航道建设工程,提出利用扭王字块进行坝体护面试验研究。结果表明,该结构具有较好的稳定性和消能功效,在航道整治建筑物中具有很好的推广利用价值。     

船舶低温冷库融霜对比试验研究

船舶伙食冷库的低温库风机盘管结霜会恶化蒸发器换热性能,影响冷藏食品品质,因此对低温库蒸发盘管必须定期融霜。船舶伙食冷库低温库一般采用热气融霜和电热融霜2种方式,经相同试验工况对比,热气融霜耗时短,效率高,库房内温度波动小,节能效果明显;低温库温度越低,热气融霜的节能效果也就越突出。对船舶冷库设计及融霜控制方式的选择具有重要借鉴意义。     

某型柴油机气体减压阀设计技术分析

通过对某型进口柴油机的气体减压阀的结构研究,分析了减压阀压力调节方式、压力比较机构、调压弹簧配置方式、阀芯受压形式和阀口密封形式等结构,深入研究了减压阀的密封性能、阀芯功能,提出了减压阀进口原件属阀芯力反馈带自密封特性的非完全平衡减压阀结构型式,阐明了该型减压阀设计的关键技术,为气体减压阀自主设计和维修提供了依据。     

Lengthscales of motions that control air–water gas transfer in grid-stirred turbulence

The relationship between the gas transfer velocity and turbulent lengthscales is investigated experimentally in a grid-stirred turbulent flow. The horizontal velocity field at the water surface is measured using particle image velocimetry (PIV). The gas transfer velocity for oxygen is obtained through reaeration experiments. In addition, the gas transfer process by surface-renewal eddies is visualized using laser-induced fluorescence (LIF) technique, in which carbon dioxide is used as the tracer gas. The definition of the Taylor microscale holds that the root-mean-square (RMS) of the surface divergence is expressed by the square root of the turbulent kinetic energy divided by the Taylor microscale. Experimentally obtained data support this scaling. They show the gas transfer velocity to be proportional to the square root of the RMS of the surface divergence. These experimental results imply that the Taylor microscale is an important parameter for gas transfer velocity at the air–water interface. These relations indicate that a nondimensional gas transfer velocity is proportional to the − 1/4 power of a turbulent-macroscale Reynolds number, which is similar to a small-eddy model, assuming that turbulent eddies with the Kolmogorov scale control the gas transfer process. However, this Reynolds number dependence does not necessarily mean the superiority of turbulent eddies with the Kolmogorov scale in the gas transfer. The LIF visualizations in horizontal and vertical planes close to the air–water interface indicate that the horizontal CO₂-concentration field has a fine spatial pattern, which resembles that of the surface divergence field, and that surface-renewal motions observed in the vertical plane have a larger lengthscale than the Kolmogorov scale. We infer from both PIV and LIF results that the Taylor microscale is an important lengthscale for air–water gas transfer.     

Validation of a dynamic mooring model coupled with a RANS solver

Standard design procedures and simulation tools for marine structures are aimed primarily for use by the offshore oil and gas. Mooring system restoring forces acting on floating offshore structures are obtained from a quasi-static mooring model alone or from a coupled analysis based on potential flow solvers that do not always consider nonlinear mooring-induced restoring forces, fluid structure interactions, and associated hydrodynamic damping effects. This paper presents the validation of a dynamic mooring system analysis technique that couples the dynamic mooring model with a Reynolds-averaged Navier-Stokes (RANS) equations solver. We coupled a dynamic mooring model with a RANS equations solver, and analyzed a moored floating buoy in calm water, regular and irregular waves and validated our motion and mooring force predictions against experimental measurements. The mooring system consisted of three catenary chains. The analyzed response comprised decaying oscillating buoy motions, linear and quadratic damping characteristics, and tensile forces in mooring lines. The generally favorable comparison of predicted buoy motions and mooring forces to experimental data confirmed the reliability of our implemented coupling technique to predict system response. Additional comparative results from a potential flow solver demonstrated the benefits of the coupled dynamic mooring model with RANS equations. The successful validated tool of coupling the dynamic mooring model with the RANS solver is available as open source, and it shows the potential of the coupled methodology to be used for analyzing the moored offshore structures.     

船舶余热梯级利用的淡水-空调复合供能系统

探讨船舶柴油机余热利用的发展潜力和当前研究现状,在此基础上根据能量梯级回收利用原则,设计一种以水/水蒸汽为单一热媒的新型淡水-空调复合供能系统,该系统包括冷却水余热回收和废气余热回收2个模块,兼具供热/制冷、制取淡水、生活用水等诸多作用。最后,对该系统进行热平衡分析,结果表明该系统可实现68.4%的余热回收量,低碳环保,节能效益显著。     

港口燃油动力设备节能减排技术

我国集装箱运输业的快速发展,极大地推动了港口起重运输设备的技术进步,每年会有更多的起重运输设备投入到港口使用,也会有一大批高耗能高排放的老旧设备面临淘汰,有关港口高耗能高排放燃油动力设备的节能减排问题会日益凸显。本文分析了国内外港口燃油动力设备的能耗和排放现状,以及相关节能减排技术的发展和研究情况,对使用生物柴油、油改气、混合动力改造、开发节能环保型新产品等节能减排技术措施进行了分析研究,为港口燃油动力流动机械节能减排工作的开展提供一些切实可行的技术措施。     

Structural behavior and design of high-strength steel welded tubular connections under extreme loading

The present work is motivated by the increasing need for cost-efficient solutions in offshore structural systems for wind energy production and for improvement of their structural performance. The structural behavior and design of high-strength steel welded tubular connections (yield strength higher than 700 MPa) subjected to monotonic and strong cyclic loading is investigated. In the first part of the paper, an experimental investigation is presented on high-strength steel tubular X-joints subjected to monotonic and cyclic loading far beyond the elastic limit of the material, leading to weld fracture. Two grades of weld metal material are employed in the welding process of the specimens. The experimental results indicate that the weld material grade has a significant influence on the deformation capacity of the welded connection under monotonic loading conditions, and its low-cycle fatigue life. The experimental procedure is simulated using advanced finite element models, elucidating several features of joint behavior and complementing the experimental results. Overall, a good agreement is found between numerical simulations and experimental results, in terms of both global response and local strains at the vicinity of the welds. Furthermore, the structural performance of the welded tubular joints under consideration is assessed using available design methodologies in terms of both ultimate strength and low-cycle fatigue resistance, in an attempt to validate an efficient design methodology for low-cycle fatigue. The results from this research effort are aimed at developing the necessary background for the possible use of high-strength steel in tubular steel lattice structures, particularly in offshore platforms for renewable energy production. They can also be used as a basis for the possible amendment of relevant design specifications and recommendations for including special provisions for high-strength steel structural systems.     

中厚度船用钢焊接技术发展现状

从电弧焊技术、埋弧焊技术、气体保护焊技术、搅拌摩擦焊（Friction Stir Welding，FSW）技术和激光焊技术等方面，对比中厚度船用钢各种焊接技术的特点和应用基础。研究发现，基于船用钢材料本身的裂纹敏感性和焊接厚度的增加，中厚度船用钢焊接技术应向激光-电弧复合焊发展，以解决现有焊接技术的焊接难点。     

Design of multi-module experiment-rig of vessel electrical propulsion prime mover

Combined power plant is widely used in large or medium surface vessel for its predominant performance. It is important to research on using combined power plant as electrical propulsion prime mover for developing the electric propulsion warship. This paper, designs a multi-module experiment-rig and introduces its composition, working principle and disposition scheme, and carried out the dynamic characteristic experiment of the GTD350 gas turbine.