Research on H2/Air rotating detonation in the hollow chamber with double injection

In order to investigate the relationship between high frequency tangential instability and continuous rotating detonation, series of H₂/Air rotating detonations are experimentally achieved in the hollow chamber with double injection sections. In the center part, gaseous H₂ and air injected by co-axial injector. Near the outer wall, the same propellants are injected in the form of slit-orifice collision. By keeping the total air mass flow rate approximately constant, varying the mixture of the inner and outer injection, series experiments are conducted in the test model with or without Laval nozzle. The results verify the possibility of rotating detonation in the hollow chamber with co-axial injector. To clarify the relationship between continuous rotating detonation and high frequency tangential combustion instability, the intrinsic frequencies of the test model are captured to be compared with propagation frequencies of detonation waves. The results show that they are close to each other when enough propellant assembled near the outer wall. In the combustor, the flame direction in constant pressure mode can change itself into rotating direction spontaneously. The results indicate that rotating detonation is an implication to high frequency tangential instability.     

PA6B柴油机进排气阀断裂原因分析

针对PA6B柴油机进排气阀断裂故障,根据现场勘验情况并结合该柴油机当时的热工参数,建立相应的故障树;对制造质量、装配质量、配气定时、异物进入、热工参数等因素进行逐一排查。结果表明:导致PA6B柴油机进排气阀断裂的原因为喷油器制造质量存在问题。     

柴油机喷油器结构参数与磨料流加工效果关联的研究

基于磨蚀模型和多相流离散相模型建立了柴油机喷油器磨料流加工过程的CFD计算模型。在验证基础模型的有效性后,分别针对喷孔直径、喷孔锥角和交点位置三种结构参数进行变参数模拟计算。通过对加工域颗粒流速、湍流强度和磨蚀率的分析,获得了喷油器主要结构参数对液力研磨加工的影响机理:喷孔直径和喷雾锥度的变化对喷孔壁面磨蚀量的影响较大,随着两者的增大,喷孔壁面的磨蚀量有所增加;交点位置由上至下的变化对喷孔壁面磨蚀量的影响较小,但是喷孔入口处磨蚀量有所增加。     

Thermal analysis of EAST neutral beam injectors for long-pulse beam operation

Two sets of neutral beam injectors(NBI-1 and NBI-2) have been mounted on the EAST tokamak since 2014. NBI-1 and NBI-2 are co-direction and counter-direction, respectively. As with indepth physics and engineering study of EAST, the ability of long pulse beam injection should be required in the NBI system. For NBIs, the most important and difficult thing that should be overcome is heat removal capacity of heat loaded components for long-pulse beam extraction. In this article, the thermal state of the components of EAST NBI is investigated using water flow calorimetry and thermocouple temperatures. Results show that(1) operation parameters have an obvious influence on the heat deposited on the inner components of the beamline,(2) a suitable operation parameter can decrease the heat loading effectively and obtain longer beam pulse length, and(3) under the cooling water pressure of 0.25 MPa, the predicted maximum beam pulse length will be up to 260 s with 50 keV beam energy by a duty factor of 0.5. The results present that, in this regard, the EAST NBI-1 system has the ability of long-pulse beam injection.     

Effect of different strut + wall injection techniques on the performance of two-strut scramjet combustor

The two-dimensional Reynolds-Averaged Navier–Stokes (RANS) equations coupled with the two equation Shear stress transport k–ω turbulence model as well as the finite-rate/eddy–dissipation reaction model have been employed to numerically simulate the flow field structures in a typical two-strut based scramjet combustor. Here all the computations have been performed by using ANSYS 14-FLUENT code. Additionally, validation has been completed for the single strut scramjet engine by comparing its outcome with the open, experimental data. The computational results show reasonable agreement with the experimental schlieren image, and the velocity, pressure and temperature variation graph available in the open literature. The introduction of two-strut improves the combustion and mixing efficiency of the combustor appreciably when compared with single strut engine. Further, investigations have been carried out on the effect of different strut + wall injector on the combustion as well mixing performance of two-strut scramjet combustor. The obtained results show that the combination of two-strut + wall 1 + wall 2 injectors provide better air–H₂ mixing as they lead to a higher penetration depth out of the other strut + wall injection techniques. Thus the combustion as well as mixing efficiency of two-strut + wall 1 + wall 2 injection technique is found to be higher as compared to remaining strut + wall injection techniques but lower than that of the two-strut injection.     

提高500TPD环形套筒窑设备运转率的措施

文章介绍了500t/d套筒窑工艺及设备改造。通过稳定操作制度、完善设备管理制度,套筒窑故障率明显下降,设备运转率提高,热工制度稳定,提高了各窑产能,避免骤冷骤热,延长耐材的使用寿命,达到稳定活性石灰质量的目的。     

基于Fluent的气固喷射器三维数值模拟研究

根据CFD和仿真思想,采用标准k-ε湍流模型,并利用拉格朗日法和欧拉法相结合的三维数值模拟技术,对气固喷射器内的流场和颗粒行为进行了数值模拟研究。对固体颗粒采用了离散相模型,考察了气固两相间的相互耦合[1]作用,结果表明:在该喷射器的接收室中,喷嘴管道周围的一些无效区域内有颗粒的聚集和停留,流场的湍动能在喷嘴出口区域周围达到最大值。其主要原因在于,喷射器中心高速射流区域周围产生了明显的回流现象,固体颗粒的加入对气体流动情况产生了一定影响,气体流场随后逐步稳定。     

绥中36-1油田注入井欠注原因及治理建议

绥中36-1油田欠注井占总注入井井数的23%,主要是注入压力高导致欠注。对该油田储层特征、注水水质、注聚井堵塞物等因素进行分析,剖析注入压力高的原因。研究表明:储层胶结疏松、泥质含量高、微粒易运移、水敏性强是储层欠注内在因素。外因主要是注水水质超标、管壁腐蚀结垢严重、聚合物吸附堵塞。通过加强腐蚀研究工作、水质分级控制、除铁杀菌以及优化加药系统等措施可有效控制注水水质。注水井酸化体系中强化对Fe、O、S等元素化合物的溶蚀,注聚系统通过加多重滤网过滤并运用复合型化学解堵剂进行解堵可有效解除注入井堵塞,达到增注的目的。     

基于Auto CAD的注射机液压系统图形库的开发与应用

液压系统是注塑机的主要部件,其性能好坏直接影响整机的运行和注射质量,应用Auto CAD的"型"建立塑料注射机液压系统CAD图形库及用参数化技术自动生成液压系统原理图的方法,较好地保证了注射机液压系统的设计质量.     

液压驱动式泵-喷嘴系统特性研究

对一种电子控制液压驱动式泵-喷嘴供油系统进行了建模与仿真,在AMEsim环境下使用机械、液压和控制部件的标准元件搭建仿真模型,用一维集总参数法进行仿真计算.利用试验测出的柱塞升程和柱塞腔内压力以及循环供油量检验模型的准确性和精度,在此基础上通过对仿真模型的优化,计算了不同控制参数下的喷油规律,对该喷油器的改进设计及其与发动机的合理匹配和供油系统控制策略的研究具有一定的指导意义.