弹箭气动力计算软件管理系统(英文)

针对反坦克导弹、低阻远程榴弹、杆式头部破甲弹、大长细比尾翼火箭弹、地空导弹、普通榴弹、脱壳穿甲弹、航空炸弹、空地导弹、超远程滑翔炮弹、航空布撒器等11个弹种研制和开发了一套工程实用、操作简便、界面友好的弹箭空气动力计算软件管理系统.本文介绍了该系统的控制系统、前置处理系统、后置处理系统和数据库系统所采用的主要技术和所实现的重要功能.     

扩展分支分析方法在飞行动力学中的应用

将分支分析和突变理论方法扩展后,应用于飞机全包线范围内平衡特性的连续计算和稳定性分析,提出了以扩展分支分析方法为基础的反馈参数连续调参的控制律设计方法。研究结果表明,扩展分支分析方法不仅能获得飞行性能指标,而且可确定非线性飞行动力学系统的稳定特性,是综合进行性能计算、品质分析及控制律设计的一种有效方法。     

喷射成形高速钢沉积坯性能分析

研究了喷射成形高速钢T15沉积坯的部分力学性能及微观组织.结果表明,喷射成形制备的高速钢,晶粒细小,无宏观偏析,平均体密度为8.208g/cm3,三点抗弯强度达到1860 MPa.但通过SEM观察发现沉积坯内存在局部显微疏松,为了进一步提高材料性能,需要对高速钢沉积坯做热等静压等后续热加工.     

昆虫翅悬停飞行中的三维空间旋涡结构

昆虫(果蝇)悬停飞行中,翅膀按照特定的拍动方式往复运动,产生非定常高升力维持身体的平衡.研究昆虫高升力机理,需要探索拍动翼运动引发的三维空间非定常流场的特性,尤其是三维空间非定常涡的发展变化过程.本文将氢气泡流动显示技术应用于动态模型实验,定性的观察拍动翼前缘涡(LEV)的发展破裂过程.并利用数字体视粒子图像测速,DSPIV(Digital Steroscopic Particle Image Velocimetry)技术,测得了拍动翼运动瞬时相位和相位平均的三维空间流场信息(速度向量场、截面涡量场、空间涡量场,以及三维空间流线),揭示了拍动翼展向流动的存在,并结合定性和定量方法多角度说明了前缘涡沿展向发展到破裂的流动结构,并说明了侧缘涡与前缘涡的相互影响.测量结果表明:在雷诺数960的情况下,拍动翼运动至相位时,翼面上前缘涡在距翼根约60%展长的位置发生破裂;翼根至破裂点之间,展向流动稳定,指向翼梢;破裂点以后,展向流改变方向,指向翼根.     

直升机起飞性能试飞方法研究

当直升机可用功率不足以维持地效外悬停时,直升机可以利用地面效应增速至一定前飞速度完成起飞。研究了地面效应和前飞速度对直升机剩余功率的影响,阐述了利用剩余功率进行有地效起飞的原理。介绍了3种有地效起飞方式,并使用水平加速—定速爬升法进行了起飞性能飞行试验,得到了水平越障距离随爬升速度的变化曲线,对飞行试验结果进行了分析,得到了有益的结论。     

直升机运输效能试飞技术研究

对直升机运输效能进行了理论分析,给出了直升机各项运输效能指标的计算方法。利用试验机进行了直升机运输效能试飞,最后给出了直升机各项运输效能指标的飞行试验结果。对于后续的直升机运输效能试飞和直升机运输效能评估等工作具有重要的参考价值。     

Numerical analysis and optimization of boundary layer suction on airfoils

Numerical approach of hybrid laminar flow control(HLFC) is investigated for the suction hole with a width between 0.5 mm and 7 mm. The accuracy of Menter and Langtry’s transition model applied for simulating the flow with boundary layer suction is validated. The experiment data are compared with the computational results. The solutions show that this transition model can predict the transition position with suction control accurately. A well designed laminar airfoil is selected in the present research. For suction control with a single hole, the physical mechanism of suction control, including the impact of suction coefficient and the width and position of the suction hole on control results, is analyzed. The single hole simulation results indicate that it is favorable for transition delay and drag reduction to increase the suction coefficient and set the hole position closer to the trailing edge properly. The modified radial basis function(RBF) neural network and the modified differential evolution algorithm are used to optimize the design for suction control with three holes. The design variables are suction coefficient, hole width, hole position and hole spacing. The optimization target is to obtain the minimum drag coefficient. After optimization,the transition delay can be up to 17% and the aerodynamic drag coefficient can decrease by 12.1%.     

考虑泄漏间隙有压流体作用的指尖密封瞬态性能分析

针对已有指尖密封性能分析工作中未考虑泄漏间隙有压流体作用使得指尖密封的理论分析与工程实际有较明显差距的问题,建立了考虑泄漏间隙中有压流体作用的指尖密封性能分析模型,对是否考虑泄漏间隙中有压流体作用的指尖密封性能差异进行了比较分析.研究结果表明:指尖密封性能分析工作需要考虑泄漏间隙有压流体的作用.考虑泄漏间隙有压流体作用指尖密封的泄漏率较不考虑有压流体作用的泄漏率最大增加了234.7%,且有压流体作用使指尖密封泄漏率随转速增加的趋势更加显著.      

Dynamic analysis of C/C composite finger seal

A seal device as an important component of aeroengines has decisive influence on per- formance, reliability, and working life of aeroengines. With the development of aeroengines, demands on the performance characteristics of seal devices are made strictly. Finger seal as a novel kind of sealing device, recently attracts more and more attentions in academic circles and engineer- ing fields at home and abroad. Research on finger seals has been extensively developed, especially on leakage and wear performances under dynamic conditions. However, it is a pity that the work on finger seals has been limited with a single approach that is improving the performance by structural optimization; in addition, the technology of dynamic analysis on finger seals is weak. Aiming at the problems mentioned above, a distributed mass equivalent dynamic model of finger seals considering the coupling effect of overlaid laminates is established in the present paper, the dynamic perfor- mance of 2.5 dimension C/C composite finger seal is analyzed with the model, and then the effects of fiber bundle density and fiber bundle preparation direction on finger seal＇s dynamic performance are discussed, as well as compared with those of Co-based alloy finger seal. The current work is about dynamic analysis of finger seals and application of C/C composite in this paper may have much academic significance and many engineering values for improving research level of finger seal dynamics and exploring feasibility of C/C composite being used for finger seals.     

载人登月人货分运与人货合运模式对比分析

由于载人航天任务所具有的确保航天员安全的特殊属性,载人登月任务模式往往因此必须考虑救生等多种环节和因素,变得十分复杂。针对目前载人登月人货分运及人货合运两种任务模式,通过比较分析表明,从安全性、任务风险、飞船设计约束、发射窗口、测控支持复杂度方面来看,人货合运模式要优于人货分运模式,但是人货合运模式中的重型火箭如果被要求按照载人火箭标准进行设计和考核,其研制周期、经费方面的投入将会增加。