井下核磁共振流体分析实验室及其应用

井下流体分析在储层实时评价有十分重要的应用. 该文介绍了NMR流体分析实验室的发展,并以哈里伯顿的井下NMR流体分析实验室为例, 详细讨论了其关键技术,包括探头结构、磁体结构和电路结构,探讨了获取流体核磁共振特性参数的测量方法. NMR流体分析实验室可以获取流体的多种重要参数,结合NMR测井能够进行综合解释,其实时评价性能实现NMR测量的优势.     

拓展小尺寸离心压气机级失速裕度机匣处理方案的数值研究

为提高一小尺寸离心压气机级的失速裕度,首先为其设计了进气回流和周向槽两种机匣处理方案,对实壁机匣和处理机匣压气机级总体性能的分析表明;进气回流并没有起到拓展压气机级失速裕度的效果,周向槽机匣处理对压气机级失速裕度的改进量也只有约2.41%。因此考虑了一种新的机匣处理方案,即同时采用进气回流和周向槽机匣处理。计算结果表明:压气机级失速裕度得到了明显的提高,提高幅度达13.25%。     

主喷管叶片中热壁面对分流管道流场特性的影响

 连续波化学激光器运转时,位于主喷管叶片内的副气流的分流管道壁面将被主喷管叶片加热而形成热壁面。通过3维的数值模拟,分析了单端、双端不同供气方式下,热壁面对分流管道流场特性的影响。热壁面将使总管气流总温沿着气流的流动方向逐渐升高,由此引起的支管入口总温的升高会降低支管的流量。无论是单端供气,还是双端供气,热壁面引起的管道流量波动幅度都要远大于绝热壁面的情况,最大波动幅度达2.16%。对进入总管的气流预热,适当增加供气总温,或将冷却管道与供气管道分开设计,气流总温变化引起的流量波动将会得到一定地抑制。     

一阶速度-应力Biot双相各向同性介质弹性波

提出一种等价的一阶双曲型速度一应力Biot双相各向同性介质弹性波波动方程,以实现双相介质混合波场中纯快慢纵波和纯横波波场分离的问题.应用散度和旋度理论证明双相介质等价方程波场分离的可行性,采用高阶交错网格有限差分法构建高精度正演算子,推导其PML吸收边界条件和稳定性条件,并对均匀双相介质和层状非均匀双相介质模型进行数值...     

Modelling of multi-bodies in close proximity under water waves——Fluid resonance in narrow gaps

Viscous fluid model and potential flow model with and without artificial damping force(f=-μV,μ the damping coefficient and V the local averaging flow velocity) are employed in this work to investigate the phenomenon of fluid resonance in narrow gaps between multi-bodies in close proximity under water waves.The numerical results are compared with experimental data available in the literature.The comparison demonstrates that both the viscous fluid model and the potential flow model are able to predict the res...     

潜热型热功能流体强化换热分析

本文建立了分析带有相变微胶囊的潜热型热功能流体的流动和换热过程数理模型,应用有限差分法和移动热源法进行联合求解。计算结果表明,相变微胶囊的加入:较好地提高了流体的换热性能。获得了相变颗粒大小和体积分数对强化换热影响等结果。计算结果对该类流体的设计和应用提供了理论依据。     

等容条件下H2O-CO2-CH4混合流体的高温拉曼光谱就位分析

 以合成包裹体作为腔体，用显微激光拉曼探针就位分析了H₂O-CO₂-CH₄混合流体的高温特性。研究结果表明，在高温下，CH₄和CO₂相互之间对各自拉曼光谱的影响不大，水分子对它们的拉曼峰有比较大的影响。在等容条件下，流体均一前，随着温度的升高，水分子的氢键几乎呈线性减少，均一为气相的流体，水分子伸缩振动拉曼峰的变化与一般气体变化相似；随着温度升高，体系压力的增加，最大峰频率呈很微小的降低趋势。均一为液相的流体中的水分子，在均一温度时，氢键变化发生了转折，均一后流体中水分子的氢键受温度的影响比均一前明显要小，在测量的最高温度520 ℃，水分子存在着一定的氢键作用。一直到拉曼光谱测量的最高温度580 ℃还未均一的流体，液相中水分子存在比较强的氢键作用。     

Accelerated Levi-Civita-Bertotti-Robinson metric in D dimensions

A conformally flat accelerated charge metric is found in an arbitrary dimension D. It is a solution of the Einstein-Maxwell-null fluid equations with a cosmological constant in D ≥ 4 dimensions. When the acceleration is zero, our solution reduces to the Levi-Civita-Bertotti-Robinson metric. We show that the charge loses its energy, for all dimensions, due to the acceleration.     

Charged fluid distribution in higher dimensional spheroidal space-time

A general solution of Einstein field equations corresponding to a charged fluid distribution on the background of higher dimensional spheroidal space-time is obtained. The solution generates several known solutions for superdense star having spheroidal space-time geometry. Formerly V. Regional College of Engineering     

Realistic rotating convection in a DNA suspension

In this work we report theoretical and numerical results on convection in a viscoelastic binary mixture under rotation for realistic rigid-rigid boundary conditions. We focus our analysis in the DNA aqueous suspensions. Instability thresholds for oscillatory convection are calculated. Finally, we analyze the stabilizing effect for the onset of convection.