叶片式混输泵气液两相流及性能的数值分析

利用Fluent计算软件在多重参考坐标系下采用欧拉方法的双流体湍流模型计算螺旋轴流式叶片泵内高含气状态下的三维气液两相流场.通过对泵内绝对流速、叶轮相对流速、静态压力、气液两相分布及其相间滑移速度矢量的分析,探讨了气液两相介质在泵内的流动规律.结果显示离心力的作用使叶轮内液相主要在轮缘附近流动,而气相则聚集在轮毂附近;泵导叶内气液两相分离状况有较明显改善.通过与泵性能实验结果对比,验证了文中方法对气液两相叶片式混输泵计算分析的有效性.     

沉积盆地地下古水动力场恢复──原理与方法

首先对地下水动力场进行了数学描述，以流体势分布度量水动力场，建立了地层埋藏史与流体压力孕育史恢复的数学模型，以此可作为恢复古水动力的重要依据；最后提出了模型实现中的一些建议，系统阐述了古水动力场恢复的原理和方法     

热卷箱式炉内板坯温度场模拟

根据热卷箱式炉中板坯卷取及保温过程的导热特点,建立了温度场计算模型,用有限元程序计算出的结果与实际基本相符,应用此模型,可对薄板坯铸连轧冲区的效果进行评估,以及有助于辅助工艺设计与优化。     

新疆高光强条件下小麦群体光合能力的研究

对新疆大陆性气候条件下春小麦群体光合能力进行研究,结果表明:新疆小麦在相同的光强下具有较高的群体表观净光合速率,具有较高的光合生产潜力,其CAP的值在-15~45μmol.m-2.s-1,与山东小麦群体光合能力比较,群体光补偿点相近,光饱和点高出1.5~3.0万lx,CAP最大值在拔节期高出4~7μmol.m-2.s-1,开花期高出6~10μmol.m-2.s-1;温光效应分析表明,光强是影响新疆春小麦群体光合能力主导生态因子,中午光强超过光饱和点是造成群体光合“午休”现象的重要原因。     

Ni-Mo四近邻作用能对Ni75Al14Mo11合金沉淀行为影响的微观相场

基于微观扩散方程,采用微观离散格点相场法研究Ni-Mo原子间四近邻相互作用能对Ni75Al14Mo11合金沉淀过程微观机制的影响。通过原子尺度的结构演化图、表征浓度和有序度的成分序参数和长程序参数分析沉淀相的有序化、簇聚、镍原子反向析出及粗化行为等。研究结果表明:最近邻、第三近邻原子间作用能增大,可促进沉淀相的簇聚及有序化,但抑制后期镍基原子团簇的反向析出及粗化;次近邻、第四近邻原子间作用能增大的影响则与之相反;在相同条件下,外层作用能对沉淀相的有序化和簇聚影响最大。     

Visualization of the complex structure and stress field inside rock by means of 3D printing technology

Accurate characterization and visualization of the complex inner structure and stress distribution of rocks are of vital significance to solve a variety of underground engineering problems. In this paper, we incorporate several advanced technologies, such as CT scan, three-dimensional（3D） reconstruction, and 3D printing, to produce a physical model representing the natural coal rock that inherently contains complex fractures or joints. We employ 3D frozen stress and photoelastic technologies to characterize and visualize the stress distribution within the fractured rock under uniaxial compression. The 3D printed model presents the fracture structures identical to those of the natural prototype. The mechanical properties of the printed model,including uniaxial compression strength, elastic modulus,and Poisson’s ratio, are testified to be similar to those of the prototype coal rock. The frozen stress and photoelastic tests show that the location of stress concentration and the stress gradient around the discontinuous fractures are in good agreement with the numerical predictions of the real coalsample. The proposed method appears to be capable of visually quantifying the influences of discontinuous,irregular fractures on the strength, deformation, and stress concentration of coal rock. The method of incorporating3 D printing and frozen stress technologies shows a promising way to quantify and visualize the complex fracture structures and their influences on 3D stress distribution of underground rocks, which can also be used to verify numerical simulations.     

沥青路面温缩裂缝的应力强度因子分析

通过有限元对沥青面层温缩裂缝尖端的应力强度因子进行分析,结果表明,在连续降温条件下,影响沥青面层内温缩裂缝应力强度因子的主要因素为初始温度和降温幅度。     

通风机房噪声模型的建立及分析

应用系统控制理论,建立通风机房噪声控制模型.在扩散声场假设条件下,采用系统学、统计学等方法来处理室内声场,避免了繁杂的数学推导.经布点监测验证,利用该模型计算通风机房噪声,预测值和实验值比较吻合,误差(ψ)在0.10～1.92 dB,平均误差为1.04 dB,模型在通风机房噪声控制是适用的.     

Mssbauer Studies of the Atomic Short-Range Order (SRO) and the Electron Transfer in Amorphous TM-M Alloys

The Mossbauer spectra of amorphous alloys Fe_(80)B_(20)-_xM_x (M=P, C, Si, Ge) at room temperature and at 4.2 K have been measured. It is found that the mean values of the hyperfine field and the isomer shift vary linearly when M substitutes for B. According to these results and those of their crystalline counterparts, it is shown that there does not exist a microcrystalline short-range order in the amorphous alloys investigated and that thc 4s electrons of iron take part in lhe charge transfer.     

高频焊管在焊接过程中三维应力场的模拟

在高频焊管生产过程中,消除因高频焊接造成的焊管残余应力是一项重要的工序,预先得出焊管残余应力场对于消除焊管残余应力具有指导意义.利用ANSYS参数化语言APDL,建立高频焊管的有限元模型,采用高频焊接线热源模型进行计算,同时考虑高频焊管有限元模型的热边界条件及物理结构约束,从而获得高频焊管在焊接过程中三维应力场及位移场...