In order to obtain the determining method of the installing angle and decrease the performance indices (cutting force and wearing rate) of the pick, the relationships among the installing angles (impact angle, inclina...In order to obtain the determining method of the installing angle and decrease the performance indices (cutting force and wearing rate) of the pick, the relationships among the installing angles (impact angle, inclination angle and the skew angle) were studied, and the static model of installing angles of the pick was built. The relationships among the impact angle, the tip angle of pick and the kinematics parameters of the pick were built, too. Moreover, the mechanic models of the maximum clearance angle and the wearing angle of the pick were set up. To research the relationships of the installing angles and the change law of the wearing angle along with the kinematics parameters, the simulation was done. In order to verify the correctness of the models, the cutting experiments were done by employing two picks with different pick tip angles. The results indicate that, the cutting force is the smallest when the direction of the resultant force of pick follows its axis, and the relationship derived among the installing angles should be satisfied. In addition, to decrease the cutting force and the wearing of the pick, the tip angle of pick should not be larger than the half of the difference between the minimum wearing angle and the impact angle of the pick, and the clearance angle must not be less than zero.展开更多
针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞...针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞试验校准数据分析了Ma=0.2~0.4对应的压力误差限;其次,开发了攻角实时解算算法,并集成到工程原理样机中;最后基于风洞试验和飞行试验对FADS系统的实时解算算法及样机进行了系统评估,并通过事后模型算法对攻角进行重新解算以评估攻角实时解算算法的可靠性。结果表明:(1)与机载惯性导航系统等其他独立测试系统解算的数据相比,飞行试验中FADS系统采用的攻角实时解算方法精度整体较好,攻角误差小于1°,在关键段小于0.5°;基于不同模型建立的FADS系统攻角解算方法得到的攻角数值基本一致,证实了开发的实时解算算法的可靠性。(2)基于风洞试验及飞行试验数据对算法误差限的考核结果显示,飞行试验初始阶段实时解算的攻角值产生波动是压力输入波动误差限较大造成的,高空低速时的压力波动幅值大是实时解算攻角值偏差较大的主要原因;建立的FADS系统的攻角解算方法在算法误差限范围内的压力波动对攻角解算值影响较小,但超过算法误差限的压力波动对攻角解算值影响显著。高空低速飞行器FADS系统对测压传感器精度水平及工程实施水平要求较高,在实际工程应用中应尽量保证测压传感器的精度水平。展开更多
爆炸成型弹丸(explosively formed projectiles,EFP)的飞行稳定性直接决定弹丸撞靶的姿态、速度和密集度,进而影响EFP的侵彻性能。为了提升高超音速(Ma=4~7)EFP的侵彻威力,综述目前EFP的构型及飞行稳定性,建立了大长径比尾裙和褶皱尾翼...爆炸成型弹丸(explosively formed projectiles,EFP)的飞行稳定性直接决定弹丸撞靶的姿态、速度和密集度,进而影响EFP的侵彻性能。为了提升高超音速(Ma=4~7)EFP的侵彻威力,综述目前EFP的构型及飞行稳定性,建立了大长径比尾裙和褶皱尾翼EFP模型;构建并验证了EFP高超音速气动参数的数值计算方法。分析了尾翼式EFP的结构参数(齿根高、齿宽、实心率)对升阻力、压心和飞行稳定性等的影响规律,研究了结构不对称程度和滚转运动对尾裙和尾翼式EFP静态气动参数的影响规律。在此基础上,建立并验证了EFP飞行动力学微分方程,分析了结构非对称和滚转运动对弹道径向偏移量的影响;研究了药型罩材质对球形、尾裙式、尾翼式EFP长距离飞行速度降的影响,定量分析了飞行稳定性对EFP存速能力的影响。研究表明:常规尾翼弹飞行稳定性判据仍适用于EFP高超音速空气弹道;通过斜置褶皱尾翼产生较低速的滚转运动,可以显著提高非对称结构EFP的空气弹道密集度;优化后的尾翼式EFP在飞行稳定性良好的同时,具有优异的存速能力,可为高侵彻威力EFP战斗部成型设计提供一个标准构型参考。展开更多
基金Project(51005232) supported by the National Natural Science Foundation of ChinaProject(20100481176) supported by the China Postdoctoral Science Foundation+1 种基金Project(201104583) supported by the China Postdoctoral Special FundProject(1101106c) supported by Jiangsu Postdoctoral Foundation, China
文摘In order to obtain the determining method of the installing angle and decrease the performance indices (cutting force and wearing rate) of the pick, the relationships among the installing angles (impact angle, inclination angle and the skew angle) were studied, and the static model of installing angles of the pick was built. The relationships among the impact angle, the tip angle of pick and the kinematics parameters of the pick were built, too. Moreover, the mechanic models of the maximum clearance angle and the wearing angle of the pick were set up. To research the relationships of the installing angles and the change law of the wearing angle along with the kinematics parameters, the simulation was done. In order to verify the correctness of the models, the cutting experiments were done by employing two picks with different pick tip angles. The results indicate that, the cutting force is the smallest when the direction of the resultant force of pick follows its axis, and the relationship derived among the installing angles should be satisfied. In addition, to decrease the cutting force and the wearing of the pick, the tip angle of pick should not be larger than the half of the difference between the minimum wearing angle and the impact angle of the pick, and the clearance angle must not be less than zero.
文摘针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞试验校准数据分析了Ma=0.2~0.4对应的压力误差限;其次,开发了攻角实时解算算法,并集成到工程原理样机中;最后基于风洞试验和飞行试验对FADS系统的实时解算算法及样机进行了系统评估,并通过事后模型算法对攻角进行重新解算以评估攻角实时解算算法的可靠性。结果表明:(1)与机载惯性导航系统等其他独立测试系统解算的数据相比,飞行试验中FADS系统采用的攻角实时解算方法精度整体较好,攻角误差小于1°,在关键段小于0.5°;基于不同模型建立的FADS系统攻角解算方法得到的攻角数值基本一致,证实了开发的实时解算算法的可靠性。(2)基于风洞试验及飞行试验数据对算法误差限的考核结果显示,飞行试验初始阶段实时解算的攻角值产生波动是压力输入波动误差限较大造成的,高空低速时的压力波动幅值大是实时解算攻角值偏差较大的主要原因;建立的FADS系统的攻角解算方法在算法误差限范围内的压力波动对攻角解算值影响较小,但超过算法误差限的压力波动对攻角解算值影响显著。高空低速飞行器FADS系统对测压传感器精度水平及工程实施水平要求较高,在实际工程应用中应尽量保证测压传感器的精度水平。
文摘爆炸成型弹丸(explosively formed projectiles,EFP)的飞行稳定性直接决定弹丸撞靶的姿态、速度和密集度,进而影响EFP的侵彻性能。为了提升高超音速(Ma=4~7)EFP的侵彻威力,综述目前EFP的构型及飞行稳定性,建立了大长径比尾裙和褶皱尾翼EFP模型;构建并验证了EFP高超音速气动参数的数值计算方法。分析了尾翼式EFP的结构参数(齿根高、齿宽、实心率)对升阻力、压心和飞行稳定性等的影响规律,研究了结构不对称程度和滚转运动对尾裙和尾翼式EFP静态气动参数的影响规律。在此基础上,建立并验证了EFP飞行动力学微分方程,分析了结构非对称和滚转运动对弹道径向偏移量的影响;研究了药型罩材质对球形、尾裙式、尾翼式EFP长距离飞行速度降的影响,定量分析了飞行稳定性对EFP存速能力的影响。研究表明:常规尾翼弹飞行稳定性判据仍适用于EFP高超音速空气弹道;通过斜置褶皱尾翼产生较低速的滚转运动,可以显著提高非对称结构EFP的空气弹道密集度;优化后的尾翼式EFP在飞行稳定性良好的同时,具有优异的存速能力,可为高侵彻威力EFP战斗部成型设计提供一个标准构型参考。
