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1.
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。  相似文献   

2.
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。  相似文献   

3.
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。  相似文献   

4.
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。  相似文献   

5.
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。  相似文献   

6.
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…  相似文献   

7.
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。  相似文献   

8.
基于有源相控阵雷达的高热耗、低能耗、高可靠性及苛刻的重量和环境适应要求,研制了压缩机制冷及常规强迫风冷复合型液冷机组。采用液冷机组与天线转台一体化设计技术,将供液单位分散布置在转台内部,制冷单元对称布置在转台两侧,大幅降低了液冷机组体积和重量。采用自动温度控制策略控制风机和压缩机启停实现高机动雷达液冷机组的低功耗。该机组结构紧凑、重量轻、可靠性高、环境适应性好,对高集成液冷机组设计提供了借鉴。  相似文献   

9.
空间相机电控机箱的热设计及仿真分析   总被引:2,自引:0,他引:2  
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。  相似文献   

10.
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。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
17.
In near-field acoustic holography sound field separation techniques make it possible to distinguish between sound coming from the two sides of the array. This is useful in cases where the sources are not confined to only one side of the array, e.g., in the presence of additional sources or reflections from the other side. This paper examines a separation technique based on measurement of the particle velocity in two closely spaced parallel planes. The purpose of the technique is to recover the particle velocity radiated by a source in the presence of disturbing sound from the opposite side of the array. The technique has been examined and compared with direct velocity based reconstruction, as well as with a technique based on the measurement of the sound pressure and particle velocity. The double layer velocity method circumvents some of the drawbacks of the pressure-velocity based reconstruction, and it can successfully recover the normal velocity radiated by the source, even in the presence of strong disturbing sound.  相似文献   

18.
A diffusion-controlled theory is developed for the formation of a low-pressure, current-free double layer just inside an upstream insulating source chamber connected to a larger diameter, downstream chamber. The double layer is described using four groups of charged particles: thermal ions, monoenergetic accelerated ions flowing downstream, accelerated electrons flowing upstream, and thermal electrons. The condition of particle balance upstream is found to determine the double layer potential. The double layer disappears at very low pressures due to loss of ionization balance upstream and due to energy relaxation processes for ionizing electrons at higher pressures, in good agreement with experiments.  相似文献   

19.
V. A. Marichev 《Surface science》1991,250(1-3):220-228
A new method has been developed for studying in situ the dependence of the electroresistance of films on the electrolyte composition and potential. The method consists of measuring the contact electroresistance between two identical metallic specimens periodically contacted in electrolyte under potentiostatic control, in particular between the walls of a fatigue crack in a sample cyclically loaded below the corrosion fatigue crack growth threshold. The sensitivity of the method is 10−9 Ω and it can be used for all conducting materials in any electrolytes at normal and high temperatures and pressures in a wide region of potentials including the potentials of the intensive evolution of hydrogen or oxygen. The method allows one to determine electroresistance of films on metals during adsorption of water and anions, formation and destruction of hydride and oxide films, electrodeposition of metals and electrochemical incorporation of cations, to study the kinetics of these processes and their dependence on potential, activators and inhibitors of corrosion. The water adsorption potentials for 16 metals are defined which are proposed to characterize the hydrophility of metals. The possibility of STM application in electrochemical double-layer structure investigations is briefly discussed in connection with the scan rate of STM and oscillation frequency of the double-layer particles. Electron tunneling between macrocontacts through thin electrolyte layers is proposed to be useful for the investigation of the processes in the double layer.  相似文献   

20.
The self-consistently generated current-free electric double layer (DL) is shown to scale up with the source tube diameter and appears not to be affected by rf driving frequency and changes in reactor geometry. This Letter presents the first simultaneous measurements of local plasma potential and beam energy as a function of axial position. The DL is shown to be no more than 5 mm thick (20 D lengths) and positioned just downstream of the maximum in the magnetic field gradient. Furthermore, its position relative to the magnetic field is observed to be invariant as the magnetic field is translated axially. Measurements of the potential drop across the DL are presented for pressures down to 0.09 mTorr and the DL strength (phiDL/T(e)) is determined to be between 5 and 7.  相似文献   

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