涡轮钻具叶片型线设计及流场模拟分析研究

涡轮叶片的型线设计对涡轮钻具的性能影响很大。以外径为127mm地质钻探用涡轮钻具为例,采用五次多项式来设计涡轮叶片的型线,使用SOLIDWORKS三维造型软件绘制了涡轮叶片的三维模型,并导入ANSYSFLOTRANCFD模块,对不同粘度下的涡轮叶片的水力性能进行了分析,获得了较为直观的速度场和压力场分布状况。结果证明,通过CFD分析,可以很好地将叶片型线的缺陷和不同状态下的涡轮钻具水力性能展现出来,对涡轮叶片的水力性能预测具有指导作用。     

考虑发育薄弱区对管涌发展影响的数学模型研究

为了揭示发育薄弱区对管涌发展的影响机制,进行了管涌砂槽模型试验和颗粒流数值模拟,建立了3组模型,以研究孔隙通道的空间发育对颗粒运移过程的影响,分析了土体内部细颗粒运移引起管涌破坏的动态过程。根据数值模拟结果,分析了管涌发展过程中试样细观及流体的变化规律,并与砂槽模型试验结果进行了比较,模拟与模型试验结果较吻合。结果表明,薄弱区越发育,压力分布调整的趋势越强,颗粒运移的趋势相应增加,达到破坏需要的时间越短。数值模拟获得的临界水力梯度与室内试验以及理论分析结果均比较接近,证明了采用颗粒流程序研究管涌问题是合理的,对研究存在薄弱区的砂土管涌现象具有明显的优势和广阔的应用前景。所揭示的结果有益于管涌机制的更深入研究。     

CFD simulation of blasting dust for the design of physical barriers

A computational fluid dynamics (CFD) model has been developed to simulate the dispersion of dust generated in blasting located in limestone quarries. This is a complex phenomenon that has been studied through the use of several digital video recordings of blasts and dust concentration field measurements by ‘light scattering’ dust collectors. In addition, the subsequent simulation of the dispersion of the dust cloud by means of multiphase CFD has also been studied. CFD calculations were carried out using software Ansys CFX 10.0, through transitory models with Lagrangian particle models crossing an Eulerian air continuous phase. This paper presents results obtained by model simulations where physical barriers are set close to the blasting, with the aim of decreasing the dust cloud dispersal and the associated environmental impact.     

Prediction of copper and chromium concentrations in bean leaves based on an artificial neural network model

The assessment of copper and chromium concentrations in plants requires the quantification of a large number of soil factors that affect their potential availability and subsequent toxicity and a mathematical model that predicts their relative concentrations in plants. While many soil characteristics have been implicated as altering copper and chromium availability to plants in soil, accurate, rapid and simple predictive models of metal concentrations are still lacking for soil and plant analysis. In the current study, an artificial neural network model was developed and applied to predict the exposure of bean leaves (BL) to high concentrations of copper and chromium versus some selected soil properties (pH, soil electrical conductivity and dissolved organic carbon). A series of measurements was performed on soil samples to assess the variation of copper and chromium concentrations in BL versus the soil inputs. The performance of the artificial neural network model was then evaluated using a test data set and applied to predict the exposure of the BL to the metal concentration versus the soil inputs. Correlation coefficients of 0.99981 and 0.9979 for Cu and 0.99979 and 0.9975 for Cr between the measured and artificial neural networks predicted values were found, respectively, during the testing and validation procedures. Results showed that the artificial neural network model can be successfully applied to the rapid and accurate prediction of copper and chromium concentrations in BL.     

Geomorphology of desert sand dunes: A review of recent progress

Through the 1980s and 1990s studies of the geomorphology of desert sand dunes were dominated by field studies of wind flow and sand flow over individual dunes. Alongside these there were some attempts numerically to model dune development as well as some wind tunnel studies that investigated wind flow over dunes. As developments with equipment allowed, field measurements became more sophisticated. However, by the mid-1990s it was clear that even these more complex measurements were still unable to explain the mechanisms by which sand is entrained and transported. Most importantly, the attempt to measure the stresses imposed by the wind on the sand surface proved impossible, and the use of shear (or friction) velocity as a surrogate for shear stress also failed to deliver. At the same time it has become apparent that turbulent structures in the flow may be as or more important in explaining sand flux. In a development paralleled in fluvial geomorphology, aeolian geomorphologists have attempted to measure and model turbulent structures over dunes. Progress has recently been made through the use of more complex numerical models based on computational fluid dynamics (CFD). Some of the modelling work has also suggested that notions of dune ‘equilibrium’ form may not be particularly helpful. This range of recent developments has not meant that field studies are now redundant. For linear dunes careful observations of individual dunes have provided important data about how the dunes develop but in this particular field some progress has been made through ground-penetrating radar images of the internal structure of the dunes.

The paradigm for studies of desert dune geomorphology for several decades has been that good quality empirical data about wind flow and sand flux will enable us to understand how dunes are created and maintain their form. At least some of the difficulty in the past arose from the plethora of undirected data generated by largely inductive field studies. More recently, attention has shifted–although not completely–to modelling approaches, and very considerable progress has been made in developing models of dune development. It is clear, however, that the models will continue to require accurate field observations in order for us to be able to develop a clear understanding of desert sand dune geomorphology.     

黏性泥石流拦挡工程数值模拟

运用计算流体动力学技术对泥石流中的Bingham黏性泥石流流体对拦挡坝的冲击进行了数值模拟,所用软件为通用CFD软件CFX,使用CAD软件AutoCAD和Unigraphics（简称UG）建立了泥石流沟谷三维地形及拦挡坝模型,计算出泥石流的速度场及泥石流流体对拦挡坝的冲击力的大小与分布。     

鄂东南丰山铜（金）矿田新一轮找矿工作新进展

丰山铜（金）矿田是鄂东南铁铜多金属成矿区内最重要的铜金矿田之一。通过实施企业科研找矿项目和国家危机矿山找矿资助项目,利用多种找矿方法相结合,对丰山铜矿深边部及外围进行了成矿预测综合研究,取得了一些对矿田成矿的新认识,建立了新的找矿模式,并成功地预测了有利的找矿靶区,经工程验证于深边部发现了可观的铜金工业矿体。上述成果表明：大中型老矿山的深边部及外围仍然是找矿最有希望、最为经济的地区。     

Mathematical model for hydraulically aided electrokinetic remediation of aquifer and removal of nonanionic copper

One of the most cost-effective in situ technologies for soil and groundwater (i.e., aquifer) remediation is electrokinetic remediation. In electrokinetic remediation, electromigration due to electric field is combined with hydromigration due to hydraulic flow by purge water to remove pollutants from aquifers through the pore water. This study aims at investigating theoretically the role of electromigration (as active movement) of pollutants and the role of hydromigration (as passive movement) of pollutants in electrokinetic remediation, and making it clear that the control variables for electrokinetic remediation are the applied voltage and the hydraulic flow rate. These aims are pursued by construction of a mathematical model based on physico-chemical considerations and by model simulations of the electrokinetic remediation applied to the virtual aquifer polluted by heavy metals of copper sulfate. According to numerical simulations with the model: (1) heavy metal (nonanionic copper) is removed from the upstream anode region and accumulated in the downstream cathode region; (2) to carry away the heavy metal outside the aquifer (global removal), hydromigration by purge water flow is essential; and (3) electromigration contributes mainly to the redistribution of heavy metals within the aquifer (local removal and local accumulation).     

Large eddy simulation of hydrocyclone—prediction of air-core diameter and shape

Hydrocyclones are widely used in the mining and chemical industries. An attempt has been made in this study, to develop a CFD (computational fluid dynamics) model, which is capable of predicting the flow patterns inside the hydrocyclone, including accurate prediction of flow split as well as the size of the air-core. The flow velocities and air-core diameters are predicted by DRSM (differential Reynolds stress model) and LES (large eddy simulations) models were compared to experimental results. The predicted water splits and air-core diameter with LES and RSM turbulence models along with VOF (volume of fluid) model for the air phase, through the outlets for various inlet pressures were also analyzed. The LES turbulence model led to an improved turbulence field prediction and thereby to more accurate prediction of pressure and velocity fields. This improvement was distinctive for the axial profile of pressure, indicating that air-core development is principally a transport effect rather than a pressure effect.     

川南早三叠世砂页岩型铜矿床沉积环境、成矿模式及对峨眉山地幔柱成矿系统的补充

峨眉山地幔柱一直以来是国内外学者的研究热点之一,近年来对峨眉山地幔柱的成矿效应的关注度持续升高,但对提供成矿物源的矿床类型研究较少,特别是对砂页岩型铜矿的研究极少,砂页岩型铜矿稳定分布在沐川西部及西南部的飞仙关组底部,以往开展了大量的勘查工作,取得了较好的找矿成果,但其成矿物质来源还有较大争议。为厘清沐川地区飞仙关组底部砂页岩型铜矿床的富集规律、沉积环境和成因机制,本研究开展了野外实地调查、矿物学、岩相古地理与岩石地球化学等系统性研究,探讨其物源、富集规律、沉积环境,建立了成矿模式。研究结果表明,沐川地区砂页岩型铜矿体产出于早三叠世飞仙关组底部的一套灰绿色细碎屑岩中,主要矿石类型有粉砂质条带黏土岩型铜矿、泥质条带粉砂岩型铜矿、粉砂岩型铜矿和细砂岩型铜矿,矿石矿物以黄铜矿、斑铜矿、辉铜矿为主;沐川地区飞仙关组底部的沉积相属于有障壁型海岸相潮坪亚相,可识别出潮上泥坪微相、潮间混合坪微相、潮下砂坪微相和潮渠微相4种微相,Cu元素主要富集于粉砂质条带黏土岩和泥质条带粉砂岩等水动力条件较弱的潮间混合坪微相中,铜的富集严格受岩相古地理及沉积相的控制; Cu元素主要来源于峨眉山高钛玄武岩,西部的康滇古陆是主要的物源区;沐川地区飞仙关组底部砂页岩型铜矿属同生沉积型矿床,其成矿模式可分为峨眉山玄武岩喷溢（矿源层形成）阶段、风化剥蚀搬运阶段、沉积富集阶段和成岩保存阶段。上述成果,对西南地区进一步实现战略性矿产找矿突破和补充完善峨眉山地幔柱成矿系统具有重要意义。     

便携式短波红外矿物分析仪(PIMA)在西藏墨竹工卡县驱龙铜矿区矿物填图中的应用

介绍了应用国内近两年新引进的便携式短波红外矿物分析仪(Portable Infrared Mineral Analyser，简称PIMA)在西藏驱龙铜矿区所做的矿物填图的工作情况，以及依据PIMA测试所获得的光谱数据进行矿物识别的初步研究成果。通过野外对探槽TC0701和TC1101系统采样和对应的光谱测试分析，识别出了与矿化和矿体有直接关系的蚀变指示矿物硬石膏(anhydrite)。在矿物识别过程中，提取到了可以作为矿区标准光谱的白云母等矿物的纯光谱曲线，并且在野外验证过程中确认了航天图像(Hyperion)上解译的零星分布的蚀变矿物绿泥石的存在。     

Numerical study of sediment transport above rippled beds under the action of combined waves and currents

To study sediment suspension above ripples under the combined action of waves and currents, a three‐dimensional numerical model has been developed based on the use of FLUENT software, and an external sediment transport model. The computer model has been tested against laboratory measurements involving oscillatory wave motion, as well as cases of co‐linear waves with following and opposing currents, with satisfactory results. Compared with the situation in which only waves are present (called waves‐alone cases), the effects from the steady current on both vortex shedding and sediment suspension above ripples have clearly been revealed by the model results. In particular, the vortices generated in combined waves and currents tend to stay low in the trough area of the ripple and are ejected earlier than those in the waves‐alone case at both the ripple crest and trough, which leads to concentration peaks at different phases and with different magnitudes. The model was also applied to a field case from a multi‐barred, dissipative beach at Egmond‐an‐Zee, in the Netherlands, to investigate the influences of a long‐shore current on cross‐shore sediment transport. The model results show reasonable overall agreement with the field measurements, as well as the important effects of the three dimensional flow structure on the sediment entrainment process close to the ripple surface, which is very difficult to observe in such detail in field studies.     

Interactive effects of the type of milling media and copper sulphate addition on the flotation performance of sulphide minerals from Merensky ore Part I: Pulp chemistry

It is well known that the chemical environment determines the success of the flotation process, however its characterisation and control is difficult to achieve. This paper, as two parts, Part I and Part II, evaluates the use of various measurements and their interpretation to gain an understanding of the influence of varying parameters such as the type of milling media and copper sulphate addition on the flotation performance of sulphide minerals from a platinum group mineral (PGM) bearing Merensky ore. It shows the complexity of interpretation and the importance of analysing flotation performance holistically. Part I focuses on the pulp chemistry and mineral potential measurements have been used to show the differences in the response of the various mineral electrodes to different conditions. The final flotation recoveries of the sulphide minerals in the ore followed the same trend as the decrease in mineral potential due to collector addition viz. chalcopyrite > pentlandite > pyrrhotite. Type of milling media and copper sulphate addition slightly affected the mineral electrode potential and flotation recovery of chalcopyrite. Addition of copper sulphate increased the recovery of pentlandite and particularly pyrrhotite due to activation by copper (II) ions. The copper activation mechanism was likely to be in the form of initial adsorption of copper hydroxide followed by reduction to Cu⁺ at the surface. However, the changes in flotation performance of the different minerals in the ore could not be completely described by the electrochemical changes, demonstrating the limitations of these measurements. Part II addresses the effect of froth stability as demonstrated by the variations in the mass and water recovery data resulting from the different milling conditions and addition of copper sulphate which emphasised the importance of considering the froth phase in the evaluation of flotation data.     

CFD simulation and experimental analysis of flow dynamics and grinding performance of opposed fluidized bed air jet mill

This paper presents a three dimensional Computational Fluid Dynamics (CFD) model to investigate the flow dynamics of solid–gas phases during fine grinding in an air jet mill. Alpine 100AFG fluidized bed air jet mill is considered for the study and the jet milling model is simulated using FLUENT 6.3.2 using a standard k-ε model. The model is developed in GAMBIT 2.3.16 and meshed by tet/hybrid (T-Grid) and Triangular (Pave) meshes. The effects of operating parameters such as solid feed rate, grinding air pressure and internal classifier speed on the performance of the jet mill are analyzed. The CFD simulation results are presented in the forms of dual phase vector plot, volume fraction of phases and particle trajectories during fine grinding process. The mass of ground feed entering and leaving the cyclone (underflow) is also computed by simulation. The proposed model gives realistic predictions of the flow dynamics within the jet mill. Experiments are conducted on the Alpine 100AFG jet mill to study the particle size, morphology and mass of the ground product. The numerical results are found in good agreement with the experimental results.     

Numerical simulation of air–soil two-phase flow based on turbulence modeling

Soil flow and induced air blasts are of great harm to humanity, and historically they have caused a lot of damage to infrastructure. However, these phenomena cannot be described by traditional analog modeling methods that limit their use in disaster prevention efforts. Computational fluid dynamics (CFD) is an applied technique commonly used in a range of fields including the chemical industry, and aircraft and automobile manufacturing, but little is reported on the use of this method to simulate flowing soil in geotechnical engineering applications. The CFD method can effectively make up for the deficiency of normal calculation methods in the analysis of soil flow and air blasts. This paper uses the FLUENT (version 6.3) CFD calculation software to simulate the processes of soil flow and induced air blast changes during soil flow with an Eulerian air–soil two-phase model included in a standard k-ε turbulence model. Velocity vectors of air blasts at different times during soil flow are obtained, and the characteristics of turbulent flow can be found based on the velocity vectors. The numerical simulation techniques adopted in this paper captured precise configurations of soil flow. The results show that the CFD method is especially suitable for simulating the process of soil flow; hazard assessments can be implemented, and the performance of structures involved with disaster prevention can be improved based on the numerical simulation of changing air blasts.     

西南三江成矿带中段羊拉铜矿体南延问题研究与找矿预测

羊拉铜矿是金沙江成矿带内规模最大的铜矿床。文章在大量分析研究前人在该区已有工作成果的基础上,综合分析羊拉铜矿区及其南部地区已有地表工程及深部工程成果,从地层、构造、岩浆岩、地球物理、地球化学特征及遥感影像特征等方面对羊拉铜矿及其南部通吉格-虽丁-加仁地区铜矿床(点)成矿地质特征进行对比研究,认为羊拉铜矿体往南进行了延伸。同时通过对羊拉铜矿以南地区铜矿床(点)成矿条件、控矿因素和矿化分布特征等进行总结,初步建立了羊拉铜矿以南地区铜矿体成矿模式,并依据成矿模式和地质条件进行了找矿预测,提出了格日-通吉格找矿靶区及虽丁-加仁找矿靶区。     

甘肃天鹿砂岩型铜矿床地质特征及成矿模式

文章在系统总结天鹿铜矿床地质特征的基础上,分析了成矿时代和矿床成因,并建立了成矿模式。结果表明,天鹿铜矿床赋存于中志留统泉脑沟山组杂色岩层中,其成矿物质来自陆源,主成矿期为中志留世,属沉积砂岩型铜矿床。     

短波红外光谱矿物测量技术在普朗斑岩铜矿区热液蚀变矿物填图中的应用

利用便携式短波红外光谱测量仪（PIMA）在云南普朗斑岩铜矿区开展了短波红外光谱测量工作,通过系统的野外数据采集,获得了研究区蚀变矿物组合及主要蚀变矿物的分布,并建立了普朗斑岩铜矿区蚀变矿物分带模式。在此基础上,建立了斑岩铜矿床找矿模型,该模型对普朗铜矿区及其外围的找矿工作具有积极的指导意义。     

乌兹别克斯坦Almalyk斑岩铜矿田成矿时代及其地质意义

新疆西天山斑岩铜矿找矿勘查备受关注。乌兹别克斯坦Almalyk斑岩铜矿田处在西天山西段,铜矿规模属亚洲第二大,但其成矿时代还没有准确厘定。在区域地质构造中,Almalyk铜矿田位于中天山加里东—华力西褶皱带南部边缘,包括Kalmakyr、Dalneye、Sarcheku和Kyzata等4个铜矿床,铜成矿主要发生在斑岩体内,原生矿石呈网脉状、浸染状,金属矿物主要有黄铁矿、黄铜矿,辉钼矿、赤铁矿、磁铁矿、自然金、斑铜矿等。针对Sarcheku铜钼矿石中辉钼矿利用Re-Os法测得(320.4±2.3)Ma的模式年龄和(317.6±2.5)Ma的等时线年龄。结合岩浆建造序列,认为矿田内构造—岩浆—热液过程开始于早石炭世,发展于晚石炭世,结束于早二叠世,斑岩型铜成矿主要在晚石炭世。西天山包括Almalyk铜矿田在内大型—超大型斑岩型铜成矿作用主要在中泥盆—晚石炭世(D2—C2),与古亚洲洋壳向哈萨克斯坦—伊犁板块之下俯冲形成的复杂岛弧岩浆地质过程有关。     

斑岩型铜矿床中铂族元素的研究现状与存在问题

铂族元素的研究在过去几十年取得了重要的进展.铂族元素可以赋存于不同的岩石类型中,形成于不同的时代.由于铂族元素具有特殊的化学性质,比较稳定且难熔于普通的酸、碱等,故铂族元素成矿具有特殊性.作为一种非常规铂族元素矿化类型,富铂族元素的斑岩型铜矿床的研究对研究铂族元素从地幔岩石圈转移进入花岗质岩石及随后从熔体进入流体并在硫化物中富集的机理,具有重要的研究意义.本文从斑岩型铜矿床中铂族元素的分布特征、矿化特征、铂族矿物特征、流体包裹体特征和富集成矿机理方面论述了斑岩型铜矿床中铂族元素的研究现状,并指出目前斑岩型铜矿床中铂族元素研究存在的主要问题,如影响斑岩型铜矿中铂族元素含量高低的影响因素不明确,富PGE斑岩型铜矿中流体包裹体研究不够系统,PGE的富集机理研究还欠深入,并指出今后我国斑岩型铜矿中PGE研究的重点,指出长江中下游地区一系列斑岩型铜矿床是我国斑岩铜矿中铂族元素研究的有利地区.