基于用户体验的人机界面发展趋势

交互设计的本质在于"以用户为本",同时也包括针对多种交互技术与形式的研究,新型的交互式技术也涉及了许多新问题和新范型,实践生产中交互设计在人机界面设计、工业产品设计以及人机工程学设计等多领域有着广泛的应用,它关注用户使用体验,旨在用先进的创意和技术为新兴市场提供整体解决方案.随着信息技术的进步、互联网平台的拓展,为人机界面设计领域带来了新的需求和挑战,将马斯洛的需求理论运用于人机界面设计领域,指出未来的人机界面设计将致力于满足用户深层次体验需求:从目前的"人—机交互"进化为"人—(机)—人交互"的观点.      

直升机旋翼对尾桨非定常气动载荷的影响

悬停和侧滑状态的直升机主旋翼桨尖涡将穿透尾桨桨尖平面,由此导致尾桨非定常气动载荷发生明显变化。为更准确地模拟由主旋翼/尾桨干扰产生的尾桨非定常气动载荷变化,通过在面元压力项中增加由旋翼桨尖涡诱导的时变项,体现旋翼桨尖涡速度和几何时变对桨叶非定常压力的影响,同时采用涡面镜像法修正涡粒子法的黏性项,确保桨叶附近区域旋翼涡量守恒,建立旋翼尾迹对尾桨叶的非定常气动干扰模型,并耦合面元/黏性涡粒子法,构建直升机主旋翼/尾桨干扰下的尾桨非定常气动载荷分析方法。通过计算AH-1G旋翼桨叶非定常气动载荷特性,并与实验测量值、计算流体力学(CFD)计算结果对比,验证本文非定常气动干扰模型的有效性。随后基于NASA ROBIN(Rotor Body Interaction)模型分析悬停、侧风和60°右侧滑状态主旋翼对尾桨非定常气动载荷的影响,分析表明主旋翼尾迹对尾桨非定常气动载荷影响显著。悬停状态的主旋翼/尾桨干扰导致尾桨拉力平均值下降、非定常气动载荷显著增加;左侧风状态,主旋翼/尾桨干扰削弱尾桨"涡环"程度,显著增加尾桨拉力和非定常气动载荷;60°右侧滑状态,主旋翼/尾桨干扰导致尾桨拉力损失最大,且在低速侧滑状态出现尾桨拉力"迅速恢复"现象,尾桨非定常气动载荷幅值迅速增加。     

风扇湍流宽频噪声特性的数值计算分析

基于Gliebe发展的风扇自噪声经验预测模型与Mugridge-Morfey发展的湍流-叶片干涉噪声分析预测模型,以GE公司R4风扇为研究对象,详细分析了风扇自噪声与转子尾迹湍流-出口导叶干涉宽频噪声(湍流干涉噪声)的特性.研究了不同的风扇设计参数和湍流参数对风扇自噪声与湍流干涉噪声的影响.计算结果表明:湍流干涉噪声对风扇宽频噪声起着主要作用,湍流干涉噪声比转子自噪声大约6~10dB,比出口导叶自噪声大约20dB.此外,出口导叶来流速度对湍流干涉噪声的影响最大,来流速度增大15%时,声功率可增大4dB左右.湍流强度对湍流干涉噪声影响较大,当湍流强度增加30%时,声功率增大约1.5dB.      

Suppressing unsteady motion of shock wave by high-frequency plasma synthetic jet

Three Plasma Synthetic Jet Actuators (PSJA) under the high-frequency actuation are used to control the Shock Wave Boundary Layer Interaction (SWBLI), a high-speed schlieren image processing method based on spatial Fourier transform as well as snapshot proper orthogonal decomposition were used to study the control effect of high-frequency plasma synthetic jet on low-frequency unsteadiness of SWBLI. The analysis of the base flow shows that the separated shock wave actually has both large- and small-amplitude vibrations at low frequency. And the results revealed that the PSJA with an operating frequency of 2 kHz has the ability to reduce the energy of low-frequency component of shock wave motion, indicating that the 2 kHz actuation can effectively suppress low-frequency unsteadiness of the separated wave. Compared with the actuation frequency of 2 kHz, the energy of low-frequency component of the shock wave is enhanced under the 8 kHz actuation, which aggravates the low-frequency unsteady motion of the shock wave. It is likely that the actuation frequency is too high, thus the intensity of the precursor shock wave induced by PSJA becomes weaker. Additionally, as the 4 kHz actuation is applied, the pulsation of the separation region was enhanced, it is speculated that the actuation frequency is coupled with the oscillation frequency of the separation region.     

火箭低空级间热分离初期流场特性数值模拟

采用耦合求解轴对称非定常NS方程与一维分离动力学方程的方法,对多级火箭低空级间热分离初期过程进行数值仿真。依据仿真结果描述低空级间热分离初期流场的两种典型结构：内部为喷管扩张段流动分离以及外部为级间缝隙横向喷流与超声速外流的干扰流场;给出两种典型流场结构中位于上面级弹体表面（喷管内）的流动分离点位置以及壁面压力分布随仿真时间的变化;初步估算流动分离线偏斜时内外流动分离区域对上面级弹体的干扰力矩。通过分析数值模拟与力矩估算结果,发现在低空级间热分离内外流场中流动分离激波后方形成的高压区域是上面级所受干扰力矩的重要来源。研究结论可为级间热分离过程干扰机理研究提供理论方向,为级间热分离时序设计提供参考。     

侧向喷流干扰流场建立与消退过程数值模拟

针对高超声速轨控侧向喷流的非定常干扰效应问题,应用非定常数值模拟方法和多重网格加速收敛技术,研究了锥-柱-裙外形轨控侧向喷流干扰流场的建立和消退过程,获得了详细的喷流瞬时干扰流场结构特性,分析了法向力放大系数、干扰力矩系数、法向力系数及俯仰力矩系数随时间的变化特性。研究结果表明：在侧向喷流干扰流场建立和消退过程中气动力变化较大,存在峰谷值;法向力放大系数及干扰力矩系数的定常值和非定常时均值之间存在明显差异。     

Forward and reverse CIR shocks at 4–5 AU: Ulysses

In this article, we study fast shocks at CIR boundaries during an extended interval of 15 consecutive major high speed solar wind streams in 1992–1993. Ulysses was 4–5 AU from the sun. The Abraham-Schrauner shock normal method and the Rankine-Hugoniot relations were used to determine fast shock directions and speeds. Out of 33 potential CIR shocks, 14 were determined to be fast forward shocks (FSs) and 14 were fast reverse shocks (RSs). Of the remaining 5 events, 2 were forward waves and 3 were reverse waves. CIR edges at latitudes below ∼30^o were, for the most part, bounded by fast magnetosonic shocks. The forward shocks were generally quasi-perpendicular (average θ_nBo = 67^o). The reverse shocks were more oblique (average θ_nBo = 52^o), but they extended to all angles. Both FSs and RSs had magnetosonic Mach numbers ranging from 1 to 5 or 6. The average Mach numbers were 2.4 and 2.6 for FSs and RSs, respectively. The shock Mach numbers were noted to generally decrease with increasing latitude. The non-shock events or waves were noted to occur preferentially at high (∼−30° to −35°) heliolatitudes where stream-stream interactions were presumably weaker. These results are consistent with expectations, indicating the general accuracy of the Abraham-Schrauner technique.     

1+1/2对转涡轮非定常流动数值模拟

为了掌握对转涡轮内部的复杂流动以改进航空燃气轮机的设计,利用数值模拟手段对所设计的1+1/2对转涡轮内部非定常流动进行了研究,将定常和非定常结果进行了详细的对比分析,结果表明:非定常结果与定常结果相比出功比减小,总效率约减小0.44%,流量基本不变,其中尾迹、激波、位势作用以及泄漏流等因素之间的相互作用是影响非定常特性的主要因素.      

火箭推进系统充液管路的流固耦合动响应分析

针对大型运载火箭推进系统中的液氧供应管路,建立流固耦合作用的模型,开展了动响应分析研究.在二维平面管系中同时分析纵向和横向振动及其相互作用,并考虑泊松耦合和连接耦合的影响,对火箭贮箱出口的充液管段模型进行了计算.结果表明:相对于经典水锤理论,考虑纵向横向振动的充液管路的流固耦合动响应形式相对复杂,频率和幅值也有变化.该研究工作为下一步的管路试验和振动抑制研究提供了参考.      

压气机中尾迹/边界层作用模型的分析与验证

基于叶轮机中尾迹的负射流效应,考虑了边界层外缘黏性力项对边界层发展的影响,推导了尾迹/边界层相互作用的数学模型,并建立了边界层动量厚度与压气机叶片负荷变化的定量关系,对模型进行了数值模拟和实验验证.结果表明:①此模型能够较好地预测尾迹通过频率对压气机负荷的影响,压气机压升随着尾迹通过频率的变化存在极大值;②尾迹引起边界层当地压力梯度变化,是影响压气机负荷的主要因素.