|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | 翼型非定常来流下复合运动动态失速仿真显示文摘针对直升机前飞时的动态失速问题,本文采用转捩修正的SST k-ω湍流模型和嵌套网格技术对雷诺数Re为3. 92×10~6时的直升机二维翼型SC1095进行数值仿真。以非定常来流条件下的纯俯仰运动为基础,对比分析了在耦合挥舞、摆振运动时,相位差、振幅对动态失速的影响;比较挥舞、摆振二者运动对于动态失速角的作用大小。结果表明:固定振幅条件下,挥舞和摆振运动相位差的增加会使动态失速角提前,升力系数峰值提高;固定相位角条件下,挥舞和摆振运动振幅的增加会使动态失速角延迟,升力系数峰值减小。挥舞运动对于非定常来流下俯仰运动翼型动态失速角的影响要大于摆振运动。本文计算方法和研究结果为翼型多自由度耦合运动下的动态失速行为预测提供参考。 | 谢凯 Laith K.Abbas 陈东阳 杨富锋 芮筱亭 | 2019 | 哈尔滨工程大学学报2019，40，5： | 10 |
| 2 | 流场环境对柔性立管湿模态的影响显示文摘为了研究静水压力和瞬态流场载荷对三维柔性立管湿模态的影响,本文基于声-固耦合模型对考虑水介质、顶张力情况下的立管进行湿模态计算,并与理论计算结果以及实验数据对比,验证了该模型的准确性;采用不考虑流-固耦合的计算流体力学(computational fluid dynamics,CFD)方法和考虑流固双向耦合的计算流体力学/计算结构力学(computational fluid dynamics/computational structure dynamics,CFD/CSD)方法分别计算了立管的瞬态流场载荷,并与实验数据对比;将水深产生的静水压力和瞬态流场载荷分别加载到三维柔性立管表面进行静力学分析,计算其湿模态。计算结果表明:立管湿模态频率比干模态频率小很多,且随着顶张力增大而增大;静水压力和瞬态流场载荷都使得湿模态频率略微增加;静水压力和瞬态流场载荷对湿模态低阶振型影响较大,对高阶振型几乎没有影响。 | 陈东阳 Laith K.Abbas 王国平 芮筱亭 | 2017 | 哈尔滨工程大学学报2017，38，10： | 6 |
| 3 | 结构误差对旋转稳定弹丸气动特性影响的数值模拟显示文摘基于剪切应力传输(SST)k-ω湍流模型,对考虑结构误差情况下的弹箭模型进行数值模拟计算。首先采用CFD和工程经验公式相结合的方法,得到了不同马赫数、不同转速情况下无结构误差模型的多种气动特性参数。通过与实验数据对比,阻力、法向力、俯仰力矩、压心位置误差在10%以内,验证了该方法的可行性和准确性。然后,建立了考虑结构误差即质量分布不对称、弹体不同轴和无结构误差模型,并分别进行了气动特性模拟计算。结果表明,质量偏心对滚转阻尼力矩系数、马格努斯力矩系数影响很大;弹体不同轴对法向力系数导数、俯仰力矩系数导数、马格努斯力矩系数导数和压心位置都产生很大影响。结构误差使模型的多种气动特性参数产生很大变化,将影响其飞行弹道和稳定性。 | 陈东阳 Laith K.Abbas 芮筱亭 王国平 | 2014 | 空气动力学学报2014，32，5： | 6 |
| 4 | 旋转弹箭气动导数与气动热仿真计算显示文摘研究弹箭气动特性优化问题,基于剪切应力传输(SST)k-ω湍流模型,分别对M910弹丸和旋转弹模型F4进行数值仿真。计算采用CFD和工程经验公式相结合的方法,得到了光弹M910和翼身组合体F4在不同攻角,不同旋转速度,不同马赫数下的气动导数分布。通过与实验数据比较分析,阻力系数,法向力系数,俯仰力矩系数导数,滚转阻尼系数误差均在工程误差范围内,验证了本文计算方法的准确性。同时,数值仿真得到旋转弹体绝热壁面温度分布云图和不同旋转速度、不同攻角的弹箭迎风面中心线上温度分布数据图。计算分析为旋转弹箭气动热弹性仿真提供有价值参考。 | 陈东阳 Laith K.Abbas 芮筱亭 | 2014 | 计算机仿真2014，31，5： | 5 |
| 5 | Transfer matrix method for determination of the natural vibration characteristics of elastically coupled launch vehicle boosters显示文摘The analysis of natural vibration characteristics has become one of important steps of the manufacture and dynamicdesignintheaerospaceindustry.Thispaperpresents a new scenario called virtual cutting in the context of the transfer matrix method of linear multibody systems closedlooptopologyforcomputingthefreevibrationcharacteristics of elastically coupled fl xible launch vehicle boosters. In this approach, the coupled system is idealized as a triple-beam system-like structure coupled by linear translational springs,where a non-uniform free-free Euler–Bernoulli beam is used.A large thrust-to-weight ratio leads to large axial accelerations that result in an axial inertia load distribution from nose to tail. Consequently, it causes the development of significan compressive forces along the length of the launch vehicle.Therefore, it is important to take into account this effect in the transverse vibration model. This scenario does not need the global dynamics equations of a system, and it has high computational efficien y and low memory requirements. The validity of the presented scenario is achieved through comparison to other approaches published in the literature. | Laith K.Abbas Qinbo Zhou Hossam Hendy Xiaoting Rui | 2015 | Acta Mechanica Sinica2015，31，4： | 3 |
| 6 | Evaluation of maize inbred lines for resistance to pre-harvest aflatoxin and fumonisin contamination in the field显示文摘Two important mycotoxins, aflatoxin and fumonisin, are among the most potent naturally occurring carcinogens, contaminating maize(Zea mays) and affecting crop yield and quality.Resistance of maize to pre-harvest mycotoxin contamination, specifically aflatoxin produced by Aspergillus flavus and fumonisin produced by Fusarium verticillioides, is a goal in breeding programs that screen for these important traits with the aim of developing resistant commercial hybrids. We conducted two years of field evaluations on 87 inbred lines originating primarily in China and Mexico and not previously screened for resistance.The objectives of our study were to identify resistant germplasm for breeding purposes and to examine possible relationships between resistances to the two mycotoxins. Aflatoxin and fumonisin were present in samples harvested from all lines in both years.Concentrations of total aflatoxin ranged from 52.00 ± 20.00 to 1524.00 ± 396.00 μg kg^(-1),while those of fumonisin ranged from 0.60 ± 0.06 to 124.00 ± 19.50 mg kg^(-1). The inbred lines TUN15, TUN61, TUN37, CY2, and TUN49 showed the lowest aflatoxin accumulation and CN1, GT601, TUN09, TUN61, and MP717 the lowest fumonisin accumulation. TUN61 showed the lowest accumulation of both mycotoxins. This study confirmed previous observations that high levels of aflatoxin can coexist with fumonisin, with 55 maize lines showing a positive correlation coefficient between the concentrations of aflatoxin and fumonisin and 32 lines showing a negative correlation coefficient. These selected lines,particularly TUN61, may provide sources of resistance to mycotoxin contamination in breeding programs. However, the mechanism of resistance in this germplasm remains to be identified. Future research should also address factors that influence the fungus–plant interaction, such as herbivory and environmental stress. | Baozhu Guo Xiangyun Ji Xinzhi Ni Jake C.Fountain Hong Li Hamed K.Abbas Robert D.Lee Brian T.Scully | 2017 | The Crop Journal2017，5，3： | 1 |
| 7 | 柔性火箭弹气动力计算精度预测显示文摘为验证小变形小攻角下基于准定常和线性理论进行柔性火箭弹气动力计算的合理性,采用计算流体力学(CFD)方法预测了某火箭弹的升力及阻力系数,并在此基础上与经验公式相结合,获得该火箭弹沿轴向的单位长度升力和阻力系数导数分布.应用多体系统传递矩阵法计算了该火箭弹的固有频率和振型,在准定常及线性理论的假设条件下,结合已得到的气动力系数导数,计算了基于火箭弹一阶振型的两个弯曲模型在不同攻角下的单位长度气动力系数分布.与CFD计算结果进行对比,发现该火箭弹在实际飞行条件下,该计算方法精度较好,在远超于实际的大变形时、攻角较大的情况下在头部和弹身处仍具有一定精度,但尾部误差较大,总体精度降低. | 李敏娇 Laith K.Abbas 芮筱亭 王国平 | 2016 | 哈尔滨工业大学学报2016，48，10： | 1 |
| 8 | Nitriding molybdenum: Effects of duration and fill gas pressure when using 100-Hz pulse DC discharge technique显示文摘Molybdenum is nitrided by a 100-Hz pulsed DC glow discharge technique for various time durations and fill gas pressures to study the effects on the surface properties of molybdenum. X-ray diffractometry(XRD), scanning electron microscopy(SEM), and atomic force microscopy(AFM) are used for the structural and morphological analysis of the nitrided layers. Vickers' microhardness tester is utilized to investigate surface microhardness. Phase analysis shows the formation of more molybdenum nitride molecules for longer nitriding durations at fill gas pressures of 2 mbar and 3 mbar(1 bar = 105Pa). A considerable increase in surface microhardness(approximately by a factor of 2) is observed for longer duration(10 h) and 2-mbar pressure. Longer duration(10 h) and 2-mbar fill gas pressure favors the formation of homogeneous, smooth, hard layers by the incorporation of more nitrogen. | U.Ikhlaq R.Ahmad M.Shafiq S.Saleem M.S.Shah T.Hussain I.A.Khan K.Abbas M.S.Abbas | 2014 | Chinese Physics B2014，23，10： | 0 |
| 9 | Aero-thermo-elastic Numerical Calculation and Analysis of Spinning Rocket显示文摘The application of computational fluid dynamics/computational solid method(CFD/CSM)on solving the aero-thermo-elastic problem of spinning rocket is introduced.Firstly,the aerodynamic coefficients of a rocket are calculated,and the results are compared with the available experimental data,which verified the accuracy of the CFD output.Then,analysis is carried using ANSYS Workbench multi-physics coupling platform,which includes fluid,thermal,and structural solvers.The results show that spinning causes a significant effect on the deformations and stresses.Furthermore,thermal stresses due to high temperature at the rocket warhead and tail edges have a dominated effect,even more than those produced by aerodynamic forces.Consequently,this important outcome should be taken into consideration during the rocket design stages. | 陈东阳 Laith K.Abbas 芮筱亭 Marzocca Piergiovanni 王国平 | 2014 | Transactions of Nanjing University of Aeronautics and Astronautics2014，31，6： | 0 |
| 10 | Non-linear Aerothermoelastic Modeling and Behavior of a Double-wedge Lifting Surface显示文摘The design of the re-entry space vehicles and high-speed aircraft structures requires special attention to the non-linear thermoelastic and aerodynamic instabilities.The thermal effects are important since temperature environment influences significantly the static and dynamic behaviors of flight structures in supersonic/hypersonic regimes.The dynamic behavior of a double-wedge lifting surface with combined freeplay and cubic stiffening structural nonlinearities in both plunging and pitching degrees-of-freedom(DOF) operating in supersonic/hypersonic flight speed regimes has been analyzed.In addition a third order piston theory aerodynamics(PTA) is used to evaluate the non-linear unsteady aerodynamic loads applied to the wing section.Loss of torsional stiffness that may be incurred by lifting surfaces subjected to axial stresses induced by aerodynamic heating is also considered.The aerodynamic heating effect is estimated based on the adiabatic wall temperature due to high speed airstreams.It is demonstrated that serious losses of torsional stiffness may occur in such lifting surfaces;the influence of various parameters such as flight condition,thickness ratio,freeplays and pitching stiffness nonlinearity are discussed. | Laith K.Abbas 芮筱亭 P.Marzocca | 2009 | Journal of Shanghai Jiaotong university(Science)2009，14，5： | 0 |
| 11 | Evaluation of maize inbred lines and topcross progeny for resistance to pre-harvest aflatoxin contamination显示文摘Pre-harvest aflatoxin contamination occurs in maize following kernel colonization by Aspergillus flavus. Aflatoxin contamination resistance is a highly desired trait in maize breeding programs.The identification of novel sources of resistance to pre-harvest aflatoxin contamination is a major focus in germplasm screening efforts. Here, we performed a field evaluation of 64 inbred lines over two years for pre-harvest aflatoxin contamination. Topcrosses were also performed with two testers, B73 and Mo17, to generate 128 F1 hybrids which were also evaluated over two years. Hybrid performance was used to calculate both general combining ability(GCA) of the inbreds, and observed heterosis for aflatoxin resistance. Over both years of the study, aflatoxin concentrations ranged from 80 ± 47 to 17,617 ± 8816 μg kg^(-1) for inbreds, and from 58 ± 39 to 2771 ± 780 μg kg^(-1) for hybrids with significant variation between years and lines. The inbred lines CML52, CML69, CML247, GT-603, GEMS-0005, Hi63, Hp301, and M37 W showed <1000 μg kg^(-1) of aflatoxin accumulation in both years of the study and less than the resistant check, Mp313 E, in at least one season. Among these, CML52, GT-603, and Hi63 also showed significant GCA with the testers in hybrid progeny. CML52, GT-603, and M37 W also showed heterotic effects of-13.64%,-12.47%, and-24.50%, respectively, with B73 resulting in reduced aflatoxin contamination. GT-603 also showed a similar heterotic effect for aflatoxin contamination,-13.11%, with Mo17 indicating that this line may serve as a versatile source of aflatoxin contamination resistance in breeding programs. | Jake C.Fountain Hamed K.Abbas Brian T.Scully Hong Li Robert D.Lee Robert C.Kemerait Baozhu Guo | 2019 | The Crop Journal2019，7，1： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员