旋转状态下曲率对气膜与主流掺混区域的影响

气膜冷却是应用于航空燃气轮机上的冷却技术,旋转及表面曲率是影响气膜与 主流掺混区域的重要因素,通过数值计算方法对旋转状态下曲率对气膜与主流掺混区域的影 响进行了研究,湍流模型选取了k-ω模型.增加旋转速度,会引起吸力面气膜的分离; 固定转速,降低表面曲率半径,压力面气膜发生分离,吸力面气膜冷却效果得到改善.当动 量流量比在小于1的范围内变化时,旋转只改变压力面气膜与主流掺混区域的分布,而对吸 力面没有影响.      

Effect of Coriolis and centrifugal forces on flow and heat transfer at high rotation number and high density ratio in non orthogonally internal cooling channel

Numerical predictions of three-dimensional flow and heat transfer are performed for a two-pass square channel with 45° staggered ribs in non-orthogonally mode-rotation using the second moment closure model. At Reynolds number of 25,000, the rotation numbers studied were 0,0.24, 0.35 and 1.00. The density ratios were 0.13, 0.23 and 0.50. The results show that at high buoyancy parameter and high rotation number with a low density ratio, the flow in the first passage is governed by the secondary flow induced by the rotation whereas the secondary flow induced by the skewed ribs was almost distorted. As a result the heat transfer rate is enhanced on both co-trailing and co-leading sides compared to low and medium rotation number. In contrast, for the second passage, the rotation slightly reduces the heat transfer rate on co-leading side at high rotation number with a low density ratio and degrades it significantly on both co-trailing and co-leading sides at high buoyancy parameter compared to the stationary, low and medium rotation numbers. The numerical results are in fair agreement with available experimental data in the bend region and the second passage, while in the first passage were overestimated at low and medium rotation numbers.     

外挂物投放 发射过程数值仿真中的非均匀流场计算

本文介绍了用面元法计算外挂物投放/发射过程中的非均匀流场问题。理论分析表明三角形奇点分布形态在非均匀流场计算中具有其独特的优越性。本文还阐述了伍德沃德程序中机翼线性变化源分布中法向扰动速度公式的错误。数值结果表明,理论计算与实验值吻合较好。     

飞机外挂物离机过渡过程的有限元算法.

研究飞机外挂物在按给定轨迹下沉旋转的离机过渡过程中，流场非结构网格的调整和再生成方法以及过渡过程欧拉方程有限元数值解法。中指出外挂物运动时流场网格调整或再生成仅需在围绕在外挂物的一小区内进行以减少计算量，而且固定网格的欧拉方程的有限元数值解法也可适用于运动网格情况，只要将固定网格的守恒通量项Fk用运动网格的Ek来代替，并建立了Fk和Ek之间的关系。末给出了带外挂物飞机的实例计算结果。     

企业产权主体的会计控制问题研究

在两权分离的条件下 ,企业经营者与所有者由于利益不一致、信息不对称、权力不对称的客观存在 ,常使企业会计控制偏离“保证会计信息真实 ,实现企业价值最大化”的控制目标 ,形成内部人控制。究其原因在于会计控制方法与理论不应该仅限于研究经营者如何进行内部会计控制 ,应拓展到所有者的外部会计控制 ,建立完善的企业会计控制体制。     

人工神经元网络在铸钢件工艺设计中的应用

以人工神经元网络实现铸钢件几何模数、挂砂层种类、挂砂层厚度、冷铁厚度与凝固模数之间的非线性映射关系，网络对检验样本的输出误差小，误差分布合理，能根据铸钢件的凝固补缩要求快速准确地确定铸钢件外冷铁工艺参数。     

熔盐泵外特性及内部流动的试验及数值模拟

为了揭示熔盐泵内两相流动的规律,研究了熔盐泵试验方法,得到了熔盐泵的外特性.采用粒子成像测速（PIV）技术测量了蜗舌附近熔盐泵内流动,并对熔盐泵内两相流动进行了非定常数值模拟,阐述了试验结果与模拟结果之间的差别,获得了晶体颗粒在熔盐泵内的体积分数分布,并分析了其演化规律.结果表明:熔盐泵内晶体颗粒体积分数分布较稳定,颗粒集中于叶片吸力面附近.粒径对颗粒在叶轮流道内的积聚影响比较大,粒径越大,颗粒积聚越明显.熔盐泵出口静压周期性波动,波动幅度受叶轮内颗粒体积分数分布影响.      

View makes a difference: Presenting human figures from the back or front affects mental spatial transformations of children and adults

Previous research suggested that performance in spatial judgments involving rotated human figures is poorer if these figures are presented from the front than from the back. We further investigated this effect, controlling for visible facial information in front and back view by presenting figures' faces as profile. Children's and adults' judgments were still faster and less error prone if figures were presented from the back. Moreover, reaction times indicated that participants did not mentally rotate figures in front view. Children performed overall more poorly than adults, but there were also qualitative differences suggesting that children are more susceptible to embodiment effects than adults. This study underlines that embodiment may have differential effects in spatial transformation tasks, enhancing or impairing performance.     

Some features of disturbed rotational motion of a satellite with a strong onboard magnet

A disturbed rotational orbital motion of an asymmetrical satellite with a strong magnet in the geomagnetic field is considered. It is shown that operating disturbances result in appearing of non-resonant phenomena in the satellite rotation caused by resonance effects.