综合模块化航空电子设备液冷散热研究进展

航空电子设备的发展趋势为综合模块化,热功耗更大,面临着百瓦级的模块的散热难题,而液冷技术是解决这一难题的首要选择。总结了国内外相关标准规范;研究了设备组成,包括机架和模块的基本结构、流道形式、加工工艺、冷却液的选择等;讨论了设计计算方法,包括冷板的设计性计算、流阻匹配性计算、应用计算流体力学方法的优化设计。提出了进一步的研究方向：建立一套关于综合模块化航空电子设备的标准规范体系;形成热-流-结构-电磁等的多场耦合优化方法;开展压力测试、应力测试、热测试、电磁屏蔽测试和腐蚀测试等测试研究。     

旋转工况下小型液冷源设计

设计了一种适用于旋转工况的小型液冷源,该液冷源采用强迫风冷换热器的原理。液冷源液路循环采用闭式系统设计以适应旋转工况的要求,液位检测采用光电式液位传感器,通过单向阀和电磁阀的组合使用可有效防止水锤效应。该系统具有体积小、重量轻、环境适应性强等优点。     

一种小型液冷系统的设计研究

设计了一种用于冷却实验室设备的小型液冷系统,采用了压缩制冷和空气冷却复合的形式。该系统通过电磁阀的通断切换压缩制冷和强迫风冷模式,并运用各种传感器对温度、压力、流量进行调节和控制。该系统具有节能、可靠性高、结构紧凑、维护方便、换热效率高等优点。     

喷射液冷阀热力学特性试验研究

1前言目前广泛使用的制冷工质R12，由于其对臭氧层的破坏，从96年起已被禁用。因为现有成熟的优良制冷工质R22具有很低的ODP值，而被公认为是近期良好过渡替代工质，并已证实十分适用于我国航运业。作者在制冷工质试验装置上，基于采用变频调速技术以R22替代R12模拟运行，并同时采用自制的喷射液冷阀，进行压缩机降低排气温度的热力学特性试验，解决替代过程中压缩机排温过高，润滑恶化的困难，为工程实际应用创造了条件。2喷射液冷阀的结构及工作原理本试验是采用喷射液冷阀，进行其热力学特性试验。喷射液冷阀在结构上与热力膨胀阀很相…     

大型液冷机组的振动测试与减振设计

针对大型液冷机组工作时产生的振动对设备和人员健康可能产生的潜在危害,对某300k W制冷量的液冷机组进行了振动测试,并根据测试结果和机组模态仿真情况,对机组进行了被动减振设计。减振后的测试结果表明,经过减振处理可有效降低工作时机组到安装基础的振动传递率,并满足相关标准要求。     

某车载功放液冷机箱热设计

针对某车载测控系统对设备小型化的设计要求,在原有功放风冷机箱的基础上,设计了一种新型液冷功放机箱的结构形式,该机箱体积小、重量轻、冷板与功放模块一体化加工,减小了接触热阻,提高了热传导效率。通过理论计算并结合热仿真设计,采用串联流道,机箱仿真最高温度为50.31℃,实测最高温度为38.5℃。结果表明,该功放液冷机箱满足结构和热设计要求。     

双冗余架构下的液冷机柜设计及性能分析

本研究以冷却对象的制冷量、供水温度以及结构尺寸等技术要求,提出了一种双冗余架构下的液冷机柜设计方案。结合各制冷零部件的安装尺寸,采用将制冷部件全部集成在3个19英寸机柜内的设计策略,且3个机柜互相拼装的结构特点。3个机柜分为：“1#制冷柜”、“2#制冷柜”和“供水柜”。其中,2个制冷柜以“镜像相同”和“冗余备份”的方式提供不低于45 kW的制冷量,供水柜则通过2台水泵“冗余备份”的方式为冷冻水提供循环动力。通过对液冷机柜的工作原理、结构布局以及控制过程的着重设计。实现了液冷机柜“1#制冷柜”和“2#制冷柜”在海水换热模式下的制冷量分别为46 kW和46.2 kW;在压缩制冷模式下的制冷量为48.8 kW和49.1 kW。     

碳氟液冷机组工程设计探索

该文旨在探索使用碳氟液体进行载冷循环的液体冷却机组的设计方法。该系统具有流量、压力和温度的监控。由于碳氟液体具有较好的性能,未来会越来越广泛的应用于电子元器件的散热冷却。     

空间相机电控机箱的热设计及仿真分析

为了保证空间相机电控机箱在轨运行期间的工作温度满足使用要求,根据电控机箱的结构特点和导热路径,对电控机箱内部大功耗电子元器件进行了详细热控设计,解决了某些电子元器件发热量大、导热路径较长的问题。以某个典型元器件为例,进行了散热效果估算。最后应用有限元分析软件IDEAS-TMG建立了详细的电控机箱热分析有限元模型,根据电控机箱所处温度边界条件进行了稳态仿真分析,给出了电控机箱整体的热响应性能、印制线路板（PCB）及板上大功耗电子元器件的稳态温度分布云图,结果显示,PCB的温度为40.6～51.1℃,板上大功耗电子元器件的结温为46.3～62.5℃,均满足热控设计的指标要求。热分析结果表明电控机箱热设计合理可行,能够满足使用要求。     

锂电池液冷结构设计与仿真分析

锂离子电池近年来被广泛应用于电动汽车之中,其对温度具有很高的灵敏度,温度过高会使得电池组电化学性能严重下降.采用双进双出的微通道液冷板换热器对电池进行热管理,为了优化液冷板的冷却性能分析了入口Re数、冷却液温度、流道宽度和流道进出口位置对电池组热性能的影响.结果 表明,在单体电池以3C电流倍率放电时该结构能够有效地将电...     

基于虚拟源技术的双层固体结构超声成像

本文提出虚拟源与合成孔径技术相结合的成像方法来实现对双层结构的内部缺陷成像。通过相控阵探头延时聚焦的方法在界面形成虚拟声源,并对有机玻璃/钢双层结构中的聚焦声场进行了仿真,结果显示聚焦声束穿过界面后形成扩散球面波,适合采用合成孔径聚焦技术成像。实验中采用128阵元探头对含有横穿孔缺陷的有机玻璃/钢样品进行测量和波形采集,应用自适应滤波方法抑制界面回波,最后对波形使用合成孔径聚焦成像,得到的图像比B扫描成像具有较高的信噪比和横向分辨率,并且分辨率不随深度变化。     

Domain structure of double layer single crystal films of iron

The domain structures of multilayered films consisting of mutually parallel single crystal (001) Fe layers and an LiF intermediate layer were studied by Lorentz microscopy. Magnetic flux transitions from layer to layer and formation of extraordinary domain walls were observed in systems with magnetic layers approximately equal in thickness. The effect of the adjacent layer on the 180° wall structure was observed.Died November 3rd, 1969.     

Upstream ionization instability associated with a current-free double layer

A low frequency instability has been observed using various electrostatic probes in a low-pressure expanding helicon plasma. The instability is associated with the presence of a current-free double layer (DL). The frequency of the instability increases linearly with the potential drop of the DL, and simultaneous measurements show their coexistence. A theory for an upstream ionization instability has been developed, which shows that electrons accelerated through the DL increase the ionization upstream and are responsible for the observed instability. The theory is in good agreement with the experimental results.     

覆黏弹层加肋双层板的声反射

为评估覆盖层的吸声性能,研究黏弹层在无限大周期加肋双层板背衬下的声反射。首先通过弯曲波与Lamb波的比较,揭示了板近似理论不适用于黏弹性板的原因。为此采用(黏)弹性理论处理(黏)弹性板,而肋板的处理则采用板近似理论,并用Hull提出的方法解决肋板和平板的耦合问题,得到反射声场的解。与板近似理论计算加肋双层板声反射的结果进行比较验证了本文方法的正确性,对反射系数进行计算分析了背衬对声反射的影响,定义平均反射系数比较了不同覆盖层的性能。结果表明,频率较低时覆盖层无法有效抑制背衬的影响,板间流体层与双层板的耦合作用引起共振散射,肋板与双层板的耦合作用降低声反射。     

Acoustic reflection of rib-stiffened double plates coated with a viscoelastic layer

To predict sound-absorbing performance of anechoic materials,the acoustic reflection problem of a viscoelastic layer backed with periodically rib-stiffened infinite double plates is studied in this paper.The reason why structural theories of plates are not applicable to viscoelastic plates is explained through comparing dispersion and attenuation curves of flexural waves with those of Lamb waves.As a result,（visco-）elastic theory is adopted to deal with（visco-）elastic plates,and ribs are treated by structural theories of plates.The coupling between ribs and plates are solved by Hull＇s method,and solution of the reflected field is obtained.The accuracy of present method is validated by comparing with the results by the structural theories of plates.The influence of a backing on the acoustic reflection of the viscoelatic layer is analyzed by computing reflection coefficients.Performances of different viscoelastic materials are evaluated by the average reflection coefficients.The computational results show that,influence of a backing on the acoustic reflection cannot be suppressed by the viscoelastic materials in low frequencies.The resonance is determined by the coupling of the fluid layer and the double plates.And ribs,which are coupled with the double plates,mainly reduce the acoustic reflection.     

Investigations and experiments of a new multi-layer complex liquid-cooled mirror

This paper describes a new multi-layer complex liquid-cooled Si mirror with 3 cooling ducts in Archimedes spirals. Utilizing the ANSYS program, the structure of the mirror is optimized and the thermal deformation model of the mirror is simulated. The simulation results show that the mirror has the following advantages:very small amount of surface deformation, uniform distribution of temperature and surface deformation,and fast surface shape restoration. The results of the experiments of thermal deformation and the surface restoration are accurately mapped to the simulation results.     

On the formation of spin dependent double layer structure in astrophysical plasmas

Double layers (DLs) are nonlinear structures, and are thought to be responsible for particle acceleration in laboratory plasmas and astrophysical plasmas. In this paper, the existence of spin dependent DLs structure is explored using separate spin evolution quantum hydrodynamic model. Based on reductive perturbation method, we derived an extended Korteweg–de Vries (eKdV) equation to demonstrate the existence and nature of DLs. We found that spin polarization significantly enhanced the amplitude of the electrostatic potential associated with DLs. Further, spin polarization also increases the depth and width of the Sagdeev potential. It is noted that the contribution of Bohm potential effect is essential for the formation of DLs structure. Our results may be helpful to explain the phenomenon of particle acceleration in dense astrophysical environments specifically in a white dwarf.     

双电子传输层结构硫硒化锑太阳电池的界面特性优化

硫硒化锑薄膜太阳电池因其制备方法简单、原材料丰富无毒、光电性质稳定等优点,成为了光伏领域的研究热点.经过近几年的发展,硫硒化锑太阳电池的光电转换效率已经突破10%,极具发展潜力.本文针对硫硒化锑太阳电池中n/i界面引起的载流子复合进行了深入研究.发现硫硒化锑太阳电池的界面特性会受到界面电子迁移能力和能带结构两方面的影响.界面电子迁移率的提高能使电子更有效地传输至电子传输层,实现器件短路电流密度和填充因子的有效提升.在此基础上,引入ZnO/Zn_1-xMg_xO双电子传输层结构能够进一步优化硫硒化锑太阳电池性能.其中,Zn_1-xMg_xO能级位置的改变可以同时调节界面和吸光层的能级分布,在Zn_1-xMg_xO导带能级为-4.2 eV,对应Mg含量为20%时,抑制载流子复合的效果最为明显,硫硒化锑太阳电池也获得了最佳的器件性能.在去除缺陷态的理想情况下,双电子传输层结构硫硒化锑太阳电池在600 nm厚时获得了20.77%的理论光电转换效率,该研究结果为硫硒化锑太阳电池...     

Observations of ion-beam formation in a current-free double layer

With nonperturbative laser-induced fluorescence measurements of ion flow, we confirm numerical simulations of spontaneous electric double-layer (DL) formation in a current-free expanding plasma. Measurements in two different experiments confirm that the DL is localized to the region of rapidly diverging magnetic field. The measurements indicate that the trapped ion population is a single Maxwellian, that the spatial gradient of the energy of ions accelerated through the DL matches the magnetic field gradient, and that DL formation is triggered when the ion-neutral collisional mean-free path exceeds the magnetic field gradient scale length.