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Wu Xianyu Li Xiaoshan Ding Meng Liu Weidong Wang Zhenguo 《中国航空学报》2007,20(6):488-494
In order to investigate the effects of fuel injection distribution on the scramjet combustor performance, there are conducted three sets of test on a hydrocarbon fueled direct-connect scramjet test facility. The results of Test A, whose fuel injection is carried out with injectors located on the top-wall and the bottom-wall, show that the fuel injection with an appropriate close-front and centralized distribution would be of much help to optimize combustor performances. The results of Test B, whose fuel injection is performed at the optimal injection locations found in Test A, with a given equivalence ratio and different injection proportions for each injector, show that this injection mode is of little benefit to improve combustor performances. The results of Test C with a circumferential fuel injection distribution displaies the possibility of ameliorating combustor performance. By analyzing the effects of injection location parameters on combustor performances on the base of the data of Test C, it is clear that the injector location has strong coupled influences on combus- tor performances. In addition, an inner-force synthesis specific impulse is used to reduce the errors caused by the disturbance of fuel supply and working state of air heater while assessing combustor performances. 相似文献
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本文用马尔文粒度分析仪测量喷雾的平均液滴尺寸及液滴尺寸分布,研究了气体注入形式对喷雾特性的影响.喷嘴压降为34.5~690kPa,喷嘴气液比为0.002~0.023.试验中使用了两种气体注入形式:一种是直径6.3mm的单孔,另一种是20个直径0.5mm的小孔.它们与三种不同孔径的喷孔配合使用.其孔径分别为0.8,1.6和2.4mm.研究结果表明,雾化质量主要取决于喷嘴压降和气液比,而对气体注入形式和喷孔直径不敏感.测量液体流量看出,此类喷嘴的流量系数很小.雾化液体中含有固体颗粒或其它易堵塞小孔或喷嘴通道的有害物时,使用这种喷嘴将会显示出它的优点. 相似文献
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LUO Cheng LIU Hua YANG Jia-ling LIU Kai-xin 《中国航空学报》2007,20(3):230-235
Crashworthiness requirement of fuel tanks is one of the important requirements in helicopter designs. The relations among the protection frame, textile layer and rubber layer of the fuel tank are introduced. Two appropriate FE models are established, one is for an uncovered helicopter fuel tank without protection frame, and the other is for fuel tank with protection frame. The dynamic responses of the two types of fuel tanks impinging on the ground with velocities of 17.3 m/s are numerically simulated for the purpose of analyzing energy-absorbing capabilities of the textile layer and protection frame. The feasibility of the current crashworthiness design of the fuel tank is examined though comparing the dynamic response behaviors of the two fuel tanks. 相似文献
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带多圈环形V型稳定器的加力燃烧室两态燃油浓度分布计算 总被引:1,自引:1,他引:1
在流场计算和油珠碰壁处理上进一步发展和完善了轨道扩散模型,编制了适用于具有多圈环形V型稳定器和多种喷油布置的加力燃烧室两态燃油浓度计算的通用程序。用于实际加力燃烧室的浓度场计算,可以给出加力燃烧室任意截面上液态、气态和总态燃油浓度分布,各区域内燃油浓度的平均值和周向平均燃油浓度沿径向的分布。 相似文献
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利用激光粒子动态分析仪 (PDA)对 180°互击型层板式喷注器的喷雾特性进行了试验研究 ,测量了喷雾典型区域的液滴速度、直径、体积通量密度等参数。分析了喷注器的雾化过程和喷雾特点 ,同时重点研究了喷口槽宽、推进剂流道面积比以及推进剂喷注速度比等参数对喷雾特性的影响。试验结果表明 :喷雾沿喷口展向可分为三个明显区域 ,中间区域流量较小但雾化较细 ,从槽两端喷出的液雾流量较大但液滴尺寸较大。对于一定的流道截面比γd 和喷注速度比γv,存在一个最佳的喷嘴槽宽w使雾化质量最优。同时 ,在喷嘴槽宽合适时 ,流道截面比γd 和喷注速度比γv 的适当增大有利于改善雾化 相似文献
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《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2020,65(4):1296-1305
This paper aims to study on the cooling effect with two types of water spray nozzle on the flame deflector during the four-engine launch vehicle take-off. To accurately simulate the two-phase flow of the rocket gas with multispecies and the water spray, the three-dimensional compressible Navier-Stokes equations, discrete ordinates methods and realizable k-Ɛ turbulence model are used to establish the rocket supersonic plumes impact model. The Eulerian dispersed phase (EDP) model was used to simulate the water spray into the exhaust gas. The accuracy and effectiveness of the gas-liquid flow model are verified by a good agreement between simulation results and experimental data. On this basis, a series of numerical simulation studies under different water injection position are performed. The results show that the high temperature regions, along the axis of engines on the deflector plate, have no significant temperature decreasing effect by water spray from the nozzles mounted on the apex of the deflector, and the high temperature converts a large quantity of water into vapor near the plume boundary, which would decrease the flow conductivity. With the cooling spray nozzle fixed directly to the deflector plate, the temperature decrease effect is obvious and the effect of thermal shock on deflector plate induced by exhaust plume is reduced, so that it can prevent the flame deflector from thermal ablation. The study results provide indepth information and engineering guidance for designing the water spray systems and increasing the safety of the launch process. 相似文献