Viscous potential flow analysis of electrohydrodynamic Kelvin–Helmholtz instability with heat and mass transfer

Viscous potential flow analysis of Kelvin–Helmholtz instability with heat and mass transfer in presence of a horizontal electric field has been carried out. Stability criterion is given by a critical value of relative velocity of two fluids as well as critical value of the applied electric field. Various graphs with respect to physical parameters, such as wave-number, viscosity ratio, ratio of dielectric constants of two fluids, heat transfer coefficients have been drawn and effect of various parameters have been described.     

稠油油藏蒸汽吞吐年油汽比的变化规律及其预测方法

以辽河油区已投入吞吐开采稠油油藏实际一切数据为基础，总结了年油汽比变化规律，建立其动态预测的数学模型，并用推广递推梯度方法，对模型中的参数进行了估计。     

大庆、大港原油对降凝剂的感受性及其非烃组份对降凝效果的影响

选用最常用的两类原油降凝剂,即乙烯-醋酸乙烯酯类共聚物和丙烯酸高碳醇酯类聚合物,以大庆、大港原油为研究对象,考察了原油降凝剂及其有关非烃组份对降凝剂降凝效果的影响.发现大庆原油对许多降凝剂之所以没有良好的感受性,是因为大庆原油中存在着一种对某些降凝剂的降凝效果有强烈抑制作用的胶质.     

土壤磁性在石油天然气早期勘探中的应用

基于“氧化还原灶”原理的非地震石油天然气的一般物化探方法,常不易于区分油气及相关因素形成的次生异常和由成岩成土作用形成的原生异常,以及测量的结果随昼夜,年季节,年份的变化,直接提取油气因素导致异常信息,开发可记录的油气作用随时间积累的勘探指标,将有可能成为非地震油气勘探的研究前沿课题,近年来,油气田上方的微磁异常和土壤磁化率异常的研究有了重要的进展,异常的含铁矿物与油气渗漏的烃类物质,氧化还原细菌     

提高稠油油藏蒸汽吞吐阶段采收率的措施

在总结了辽河田稠油油藏蒸汽吴吐的开发经验的基础上，提出了钻加密井、侧钻、分注、保证吞吐井生产周期的完整性、边部排水等５项用于改善吞吐开发效果，提高采收率的技术对策。这些对策在辽河稠油油藏的实际应用中已证实是可行的，并具有推广使用意义。     

Wind-Induced Vibration Control for Substation Frame on Viscous Damper

In order to study the wind-induced vibration control effect of the viscous damper on the large-scale substation frame, this paper takes the large-scale 1000 kV substation frame of western Inner Mongolia as an example. The time-history sample of pulsating wind load is simulated by harmonic superposition method based on Matlab software. 6 kinds of viscous damper arrangement schemes have been designed, and SAP2000 finite element software is used for fine modeling and input wind speed time history load for nonlinear time history analysis. The displacement and acceleration of a typical node are the indicators of wind vibration control. The wind-induced vibration control effects of different schemes under different damping parameters have compared, and the damping parameters are analyzed for the optimal layout scheme. The results show that a viscous damper has installed in the lower layers of the substation; a viscous damper is placed between the ground column and the lattice beam. It is an integrated optimal solution. The wind-induced vibration control effect of the optimal scheme is sensitive to the viscous damper parameters, and the control effect does not increase linearly with the increase of the damping index and the damping coefficient. Corresponding to different damping indexes, the damping coefficient has a better range of values.     

Exact Analysis of Non-Linear Fractionalized Jeffrey Fluid. A Novel Approach of Atangana-Baleanu Fractional Model

It is a very difficult task for the researchers to find the exact solutions to mathematical problems that contain non-linear terms in the equation. Therefore, this article aims to investigate the viscous dissipation (VD) effect on the fractional model of Jeffrey fluid over a heated vertical flat plate that suddenly moves in its own plane. Based on the Atangana-Baleanu operator, the fractional model is developed from the fractional constitutive equations. VD is responsible for the non-linear behavior in the problem. Upon taking the Laplace and Fourier sine transforms, exact expressions have been obtained for momentum and energy equations. The influence of relative parameters on fluid flow and temperature distribution is shown graphically. As special cases, and for the sake of correctness, the corresponding results for second-grade fluid and Newtonian viscous fluid are also obtained. It is interesting to note that fractional parameter α provides more than one line as compared to the classical model. This effect represents the memory effect in the fluid which is not possible to elaborate by the classical model. It is also worth noting that the temperature profile of the generalized Jeffrey fluid rises for higher values of Eckert number which is due to the enthalpy difference of the boundary layer.     

Heat transfer enhancement in hydromagnetic dissipative flow past a moving wedge suspended by H2O-aluminum alloy nanoparticles in the presence of thermal radiation

This letter investigates the two dimensional magnetohydrodynamic Falkner Skan flow of water saturated with AA7072–H₂O and AA7075–H₂O nanoparticles over a moving wedge. Influence of viscous dissipation and thermal radiation is also under consideration. The model is reduced into nondimensional form by using defined self-similar transformations. Then, numerical study (Runge-Kutta numerical scheme) is carried out for solution purpose. The effects of pertinent flow parameters are discussed in the flow regimes by means of graphical aid. Graphical results for special cases (static wedge and when the movement of flow and wedge is in opposite direction) of the model are also elucidated graphically. It is noted that fluid velocity decreases for volumetric fraction and magnetic force favor the velocity. Significant effects of thermal radiation and nanoparticles volume fraction pointed for thermal filed and the influence of Eckert number is almost inconsequential. For more radiative fluid heat transfer coefficient decreases and nanoparticles volumetric fraction favor the local rate of heat transfer. In the presence of AA7075 nanoparticles, rate of heat transfer is quite rapid as compared to that of AA7072 nanoparticles. To validate the present computations, some present results are compared with already existing results in the literature and found better agreement between them. Finally, major points of the study ingrained in the last section of the letter.     

Laminar nanofluid flow in microheat-sinks

In response to the ever increasing demand for smaller and lighter high-performance cooling devices, steady laminar liquid nanofluid flow in microchannels is simulated and analyzed. Considering two types of nanofluids, i.e., copper-oxide nanospheres at low volume concentrations in water or ethylene glycol, the conjugated heat transfer problem for microheat-sinks has been numerically solved. Employing new models for the effective thermal conductivity and dynamic viscosity of nanofluids, the impact of nanoparticle concentrations in these two mixture flows on the microchannel pressure gradients, temperature profiles and Nusselt numbers are computed, in light of aspect ratio, viscous dissipation, and enhanced temperature effects. Based on these results, the following can be recommended for microheat-sink performance improvements: Use of large high-Prandtl number carrier fluids, nanoparticles at high volume concentrations of about 4% with elevated thermal conductivities and dielectric constants very close to that of the carrier fluid, microchannels with high aspect ratios, and treated channel walls to avoid nanoparticle accumulation.     

Validation of a three-dimensional viscous–inviscid interactive solver for wind turbine rotors

MIRAS is a newly developed computational model that predicts the aerodynamic behavior of wind turbine blades and wakes subject to unsteady motions and viscous effects. The model is based on a three-dimensional panel method using a surface distribution of quadrilateral singularities with a Neumann no penetration condition. Viscous effects inside the boundary layer are taken into account through the coupling with the quasi-3D integral boundary layer solver Q³UIC. A free-wake model is employed to simulate the vorticity released by the blades in the wake. In this paper the new code is validated against measurements and/or CFD simulations for five wind turbine rotors, including three experimental model rotors [20–22], the 2.5 MW NM80 machine [23] and the NREL 5 MW virtual rotor [24]. Such a broad set of operational conditions and rotor sizes constitutes a very challenging validation matrix, with Reynolds numbers ranging from 5.0⋅10⁴ to 1.2⋅10⁷.