冻结造孔防斜保直实践与应用

冻结造孔施工过程中,控制井斜靶域半径问题是冻结造孔的关键点。以陕西麟北煤业开发有限责任公司园子沟煤矿冻结造孔施工为例,本文着重分析冻结造孔施工中靶域半径控制及钻孔防斜保直、测斜、定向技术实践应用。     

基于CFD的羧化釜搅拌改造设计

通过改变搅拌桨形状,对8立方液固两相体系的羧化釜进行了搅拌流场、固含率进行模拟,从流体力学角度对羧化釜进行了优化。将模拟优化结果用于实际工业生产中,结果表明:计算流体力学(CFD)模拟优化后的羧化釜能够改善釜内流体流动情况,从而对反应产生影响,使原料转化率提高了5.6个百分点。     

基于fluent紊流幂律流体偏心环空数值模拟研究

为解决常规钻井水力学公式对偏心流场计算结果与实际有所差别的问题,揭示大位移井偏心环空水力行为规律,基于fluent软件对幂律钻井液偏心环空紊流流动进行了数值模拟研究,分析偏心度、稠度系数、流性指数、屈服值、钻杆与钻头组合对流动规律的影响.结果表明,随偏心度、稠度系数、流性指数、屈服值、钻杆与钻头尺寸比例的增大,环空中宽间隙处的流速、压力逐渐增大,而窄间隙处的流速、压力逐渐减小.     

LIQUIDATION IN LIMIT ORDER BOOKS WITH CONTROLLED INTENSITY

We consider a framework for solving optimal liquidation problems in limit order books. In particular, order arrivals are modeled as a point process whose intensity depends on the liquidation price. We set up a stochastic control problem in which the goal is to maximize the expected revenue from liquidating the entire position held. We solve this optimal liquidation problem for power‐law and exponential‐decay order book models explicitly and discuss several extensions. We also consider the continuous selling (or fluid) limit when the trading units are ever smaller and the intensity is ever larger. This limit provides an analytical approximation to the value function and the optimal solution. Using techniques from viscosity solutions we show that the discrete state problem and its optimal solution converge to the corresponding quantities in the continuous selling limit uniformly on compacts.     

限制性液体复苏治疗创伤性失血性休克的临床观察

目的:探讨限制性液体复苏治疗创伤性失血性休克的疗效及对炎症因子的影响。方法:选择2008年3月至2011年3月60例创伤性失血性休克患者,随机分为对照组和观察组,每组30例。对照组采用充分液体复苏治疗,观察组应用限制性液体复苏治疗,观察两组患者的术前输液量、红细胞压积、凝血酶原时间、死亡率以及C-反应蛋白、IL-6浓度变化。结果:观察组术前输液量、凝血酶原时间、死亡率、C-反应蛋白、IL-6浓度分别是(1768.79±236.54)ml、(12.14±4.13)s、6.67%、(102.43±33.57)ng/L、(213.49±64.82)ng/L,明显低于对照组的(2876.59±287.34)ml、(17.13±3.94)s、16.67%、(124.67±37.84)ng/L、(275.61±72.35)ng/L,P<0.05。观察组术前红细胞压积是(31.45±3.25)%,显著高于对照组的(24.37±3.69)%,P<0.05。结论:限制性液体复苏治疗创伤性失血性休克临床疗效较好,减轻机体炎症反应,有利于患者康复。     

钻井液用聚丙烯酰胺钾盐中钾含量测定的不确定度评定

"测量不确定度"是当前国际上表示检测结果的通用做法,如何对测量结果的不确定度进行合理的评定,是一直以来困扰检测实验室的一个难题。依据测量不确定度的评价原则,首先通过对四苯硼钠、滴定度等一系列可能产生不确定度的分量进行计算,最后合成钾含量测定的不确定度。对钻井液用聚丙烯酰胺钾盐中钾含量测定的不确定度进行了评定,对钻井液化学剂的准确检测具有借鉴意义。     

影响蒸汽驱效果的主要因素分析

本文研究了影响蒸汽驱效果的主要因素,分析了油藏地质条件和蒸汽驱过程中的操作参数两方面因素对蒸汽驱效果的影响,总结出适合蒸汽驱的油藏地质条件和合理的蒸汽驱操作条件。     

大型散热设备安装工艺探索——超临界间接空冷“三塔合一”大型散热设备安装工艺

本文介绍在干旱地区建设的超临界间接空冷"三塔合一"大型散热设备的安装工艺,此工艺不仅提高散热设备吊装效率和安装质量而且缩短安装工期,达到降本增效的目的。     

A supportive architecture for CFD-based design optimisation

Multi-disciplinary design optimisation (MDO) is one of critical methodologies to the implementation of enterprise systems (ES). MDO requiring the analysis of fluid dynamics raises a special challenge due to its extremely intensive computation. The rapid development of computational fluid dynamic (CFD) technique has caused a rise of its applications in various fields. Especially for the exterior designs of vehicles, CFD has become one of the three main design tools comparable to analytical approaches and wind tunnel experiments. CFD-based design optimisation is an effective way to achieve the desired performance under the given constraints. However, due to the complexity of CFD, integrating with CFD analysis in an intelligent optimisation algorithm is not straightforward. It is a challenge to solve a CFD-based design problem, which is usually with high dimensions, and multiple objectives and constraints. It is desirable to have an integrated architecture for CFD-based design optimisation. However, our review on existing works has found that very few researchers have studied on the assistive tools to facilitate CFD-based design optimisation. In the paper, a multi-layer architecture and a general procedure are proposed to integrate different CFD toolsets with intelligent optimisation algorithms, parallel computing technique and other techniques for efficient computation. In the proposed architecture, the integration is performed either at the code level or data level to fully utilise the capabilities of different assistive tools. Two intelligent algorithms are developed and embedded with parallel computing. These algorithms, together with the supportive architecture, lay a solid foundation for various applications of CFD-based design optimisation. To illustrate the effectiveness of the proposed architecture and algorithms, the case studies on aerodynamic shape design of a hypersonic cruising vehicle are provided, and the result has shown that the proposed architecture and developed algorithms have performed successfully and efficiently in dealing with the design optimisation with over 200 design variables.     

汽车空调风道出风情况的CFD分析与优化

文章建立了某车型汽车空调风道结构的三维数学模型,利用商业软件Fluent进行模拟,得到了风道出风口风量大小和风量的分配情况,并与设计值进行了比较;在此基础上,分析了风道出口扫风情况,提出了解决方案,对改进和优化风道结构,提高汽车空调整体性能具有一定的参考价值。