液动式单螺杆泵的原理及设计

介绍了一种新型的潜油（ 水） 泵装置的设计计算步骤。

双曲度蒙皮零件主动式充液成形技术研究

双曲度蒙皮零件在航空制造领域应用广泛,基于截面尺寸变化较大,具有局部特征的复杂蒙皮类零件提出了主动式充液成形技术。液室压力的加载是主动式充液成形的关键参数之一,通过数值模拟分析了不同液体加载速率条件下2A12-O铝合金双曲度蒙皮零件底部破裂危险点与两端起皱危险点的应变轨迹的变化规律,同时讨论了不同液体加载速率下对壁厚分布的影响。结果表明:合理的液体压力加载速率可以明显的改善应变路径,有效的降低纵向应变,抑制双曲度蒙皮零件底部的过渡减薄,改善了零件的表面质量。

汽车筒式液阻减振器技术的发展

分析了汽车乘坐舒适性／行驶平顺性和操纵稳定性对筒式液阻减振器特性的要求，指出汽车在不同行驶工况下对减振器特性的要求是不同的；分析了被动式减振器的发展历程及非充气和充气减振器的特点，阐述了机械控制式可调阻尼减振器、电子控制式减振器以及电流变和磁流变液体减振器等的结构特点、工作原理及其动态特性；分析了筒式液阻减振器基于经验设计／实验修正开发方法的缺点，阐述了基于ＣＡＤ／ＣＡＥ技术的现代设计开发方法的过程及其关键问题；最后分析了我国筒式液阻减振器技术的发展状况及问题，展望了减振器技术的发展前景。

液压传动在万能外圆磨床设备中应用研究

在机械工程领域液压传动有着举足轻重的作用,尤其是实现设备的自动化。本文通过对工程机械中万能外圆磨床工作台往复运动及为满足短小零件快速磨削需要的工作台抖动油路、工作台手动与液动相互切换及互锁油路、砂轮架的快速进给及退出油路、尾架顶尖的夹紧与松开油路、机床各部位润滑及丝杠螺母副间隙的消除油路做详尽分析;并总结万能外圆磨床液压传动系统的结构特点,对于后期万能外圆磨床液压传动系统的升级、改造及创新设计具有一定的参考价值和指导意义。

基于StarCCM+的电动汽车液冷电池组散热器仿真分析

为了解纯电动汽车电池包液冷散热系统散热器的散热性能,对液冷散热系统进行结构分析和仿真分析。首先对纯电动汽车电池组液冷散热系统进行结构分析,然后在CATIA中建立散热器三维实体模型,并导入StarCCM+中,利用其自带的网格划分功能划分多面网格,并设置仿真参数。对电动车行驶过程中由于故障原因导致的散热器高温现象进行了冷却方案设计。最后,利用StarCCM+得到不同方案下散热器温度场、速度场及温升情况,分析不同冷却方案下散热器冷却速度,得出最优冷却方案。

凸轮盖板零件主动式充液成形仿真、试验及微观组织研究

以飞机凸轮盖板零件为研究对象,根据零件的几何尺寸,利用商业Catia软件建立其三维模型,并结合网格剖分软件和Dynaform有限元软件,进行主动式充液成形仿真、试验及微观组织和力学性能研究。基于增量有限元法,根据不贴模和回弹的变形情况,对主动式充液成形中加载与卸载回弹过程的变形进行了工艺仿真分析,设计了主动式充液成形模具,研究了工艺参数对零件成形质量和回弹的影响规律。在最佳的工艺参数下,制备了凸轮盖板零件实物,研究了其周向和法向的硬度值、厚度值和微观组织,并得到了相关的变化规律,为主动式充液成形工艺设计与优化奠定理论基础。

乌克兰的几种新型解卡震击器

国家经济的高速增长推动了对矿产能源的需求,使钻探工作量逐年增加。面对深孔复杂地层,钻探过程中卡钻事故时常发生。震击器是解决卡钻事故的有效措施,但油气钻井中常用的震击器在小口径的地质钻探中使用效果并不理想,因此设计适用于地质岩心钻探的新型震击器十分必要。介绍了乌克兰针对比较严重的卡钻事故而设计的带弹簧加压式阀门的液动震击器,在保证其工作可靠性的同时,利用其高频的冲击功可以大大提高解卡工作的效率;针对比较容易发生卡钻地区而设计的随钻式机械震击器,可以在卡钻发生后第一时间进行解卡工作,避免了卡钻事故的进一步恶化,有效的节省了处理卡钻事故的时间。这种解决地质钻探中卡钻事故的有效技术工具,引进、推广应用前景广泛。

堆取料机的供电装置

介绍了装卸设备上常使用的三种电缆卷筒：力矩式电缆卷筒、磁滞式电缆卷筒、液动式电缆卷筒驱动方式的工作原理、调试要点和主要优缺点。

LARGE-EDDY SIMULATION OF TWO-PHASE REACTING FLOW IN MODEL COMBUSTOR

The gas-droplet two-phase reacting flow in a model combustor with the V-gutter flame holder is studied by an Eulerian-Lagrangian large-eddy simulation (LES) approach. The k-equation subgrid-scale model is used to simulate the subgrid eddy viscosity, and the eddy-break-up (EBU) combustion subgrid-scale model is used to determine the chemical reaction rate. A two-step turbulent combustion subgrid-scale model is employed for calculating carbon monoxide CO concentration, and the NO subgrid-scale pollutant formation model for the evaluation of the rate of NO formation. The heat flux model is applied to the prediction of radiant heat transfer. The gas phase is solved with the SIMPLE algorithm and a hybrid scheme in the staggered grid system. The liquid phase equations are solved in a Lagrangian frame in reference of the particle-source-in-cell (PSIC) algorithm. From simulation results, the exchange of mass, moment and energy between gas and particle fields for the reacting flow in the afterburner with a V-gutter flame holder can be obtained. By the comparison of experimental and simulation results, profile temperature and pollutant of the outlet are quite in agreement with experimental data. Results show that the LES approach for predicting the two-phase instantaneous reacting flow and pollutant emissions in the afterburner is feasible.

Effects of Orifice Orientation and Gas-Liquid Flow Pattern on Initial Bubble Size

In many gasliquid processes, the initial bubble size is determined by a series of operation parameters along with the sparger design and gasliquid flow pattern. Bubble formation models for variant gasliquid flow pat terns have been developed based on force balance. The effects of the orientation of gasliquid flow, gas velocity, liquid velocity and orifice diameter on the initial bubble size have been clarified. In ambient airwater system, thesultable gasllquid flow pattern is important to obtain smaller bubbles under the low velocity liquid crossflow con ditions with stainless steel spargers. Among the four types of gasliquid flow patterns discussed, the horizontal orifice in a vertically upward liquid flow produces the smallest initial bubbles. However the orientation effects of gas and liquid flow are found tobe insgnifican whenliq.uid velocity is.higher than. 3.2 m;sa or theorifice diameter is small enough.

Study on heat transfer for falling liquid film flow with consideration of interfacial evaporation

The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial eveiporative heat transfer in the turbulent model would lower the predicted convective heat transfer coefficient. Predictions of the new model resulted in a prominent deviation from that predictions of the normal model in the case of large mass flow rate and low wall heat flux. This deviation will be decreased with increasing wall heat flux, such that it will be asymptotic zero at very high wall heat flux. Predictions of the new model agreed well with the current experimental measurements. This study has verified that the Reynolds number is not the sole crucial parameter for heat transfer of falling liquid film flow, and wall heat flux will be another important independent parameter. This result is consistent with our previous studies.

Preliminary investigation of tumor angiogenesis and blood flow pattern in solitary bronchogenic adenocarcinoma: radiologic-pathologic correlation

Objective: To investigate the correlations of vascular endothelial growth factor (VEGF)-positive tumor angiogenesis and the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma. Methods: 30 patients with VEGF-positive bronchogenic adenocarcinomas (diameter ≤ 4 cm) underwent multi-location dynamic contrast material-enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4 mL/sec by using an autoinjector) serial CT. The quantifiable parameters (Perfusion, peak height, ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta and mean transit time) of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma were compared with microvessel densities (MVDs) and VEGF expression by immunohistochemistry. Results: Peak height of VEGF-positive bronchogenic adenocarcinoma was 36.06 HU ± 13.57 HU, bronchogenic adenocarcinoma-to-aorta ratio 14.25% ± 4.92, and perfusion value 29.66 ± 5.60 mL/min/100 g , mean transit time 14.86 s ± 5.84 s, and MVD 70.15 ± 20.03. Each of peak height, ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta and perfusion correlated positively with MVD (r = 0.781, P < 0.0001; r = 0.688, P < 0.0001; r = 0.716, P < 0.0001; respectively). No significant correlation was found between mean transit time and MVD (r = 0.260, P = 0.200 > 0.05). Conclusion: Perfusion, peak height and ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta reflect MVD in VEGF-positive bronchogenic adenocarcinoma. Perfusion, peak height and ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta derived with dynamic CT might be index for VEGF-related tumor angiogenesis in bronchogenic adenocarcinoma.

THE STATIC PERFORMANOE AND PARAMETER STUDY OF FLOATING-RING HYDRODYNAMIC THRUST BEARINGS

In this paper, floating--ring thrust bearings are investigated. A mathematical model is established to analyze the static performance of this kind of bearings, such as the load capacity, frictional power loss, temperature rise as well as the angular speed ratio between the floating ring and runner.Meanwhile, a parameter study is also conducted on the characteristics of floating-ring thrust bearings.Finally, the theoretical calculation results are verified by experiments.

Cost-Effective Approaches of Circumferential Electro Wedge Brake for Reducing Unbalance-Wears

Existing hydraulic braking systems in the vehicle is composed of the brake pedal, the hydraulic booster and the hydraulic caliper. The driver transmits one＇s breaking intent through the brake pedal stroke and force. The hydraulic booster can amplify the pedal force, only when the engine operates. The hydraulic caliper is composed of cylinders, pistons. There are also hydraulic pipes from the booster to the caliper. Currently, X-By-Wire technology is researched actively due to the exhaustion of fuel and the regulation of CO2. As a chain of this trend, the e-pedal and an electric mechanical brake （EMB） also are highlighted. At the beginning of EMB development, high-torque and high-power motors are required in order to implement the existing hydraulic calipers＇ clamping force. This has some limits as the need of big spaces and high costs. Then the electro wedge brake （EWB） is launching with self-reinforcement features of the wedge structure. EWB can generate big clamping forces with small size and low-torque motors with good braking-efficiency. In recent, the disc＇s circumferential face clamping one has been researched, for better heat-emission ability and better braking-efficiency compared to the existing disc＇s lateral face clamping method. But, this circumferential face clamping method can have worse unbalance-wear features compared to lateral face clamping one. In this study, the authors describe their circumferential EWB concepts, the method for reducing unbalance-wear feature of circumferential EWB, and the cost-effective implementation of circumferential EWB, in particular focused on nonlinear counter-wedge profile which is appropriate to reduce unbalance-wear.

Liquid Flow Characteristics inside Impeller Rotational Region of an Unbaffled Vessel Agitated with an Unsteadily Angularly Oscillating Impeller

Characteristics of the liquid flow were studied in the impeller region for an unbaffied vessel agitated with an angularly oscillating impeller whose rotation proceeds while periodically reversing its direction at the set angle, namely, rotating unsteadily with sinusoidal variation of the set amplitude. Measurement of the velocity of the liquid flow was performed, abreast of that of the torque of the shaft attached with the impeller. A disk turbine impeller with six flat blades was used in angular oscillation mode at the different amplitudes. The power characteristics were analyzed with the power number during one cycle of the angular oscillation consisting of a process for the impeller to stop and to reverse and that to rotate with a certain acceleration-deceleration in a uniform orientation. The power number in the process for the impeller to rotate exhibited slightly lower values compared with that of the identical design of impeller used in unidirectional rotation mode in a fully baffled vessel, being higher values in its process to stop and to reverse. Under such an operating condition in the amplitude, a time series of images was analyzed by particle tracking velocimetry （PTV） to characterize the fluctuation components of the velocities of the circumferential and radial flows inside the impeller rotational region. The impeller in its rotation process produced flows having a relatively large turbulence, independent of the amplitude condition. For the radial flow relating to the discharge flow, which contributes to transport of the turbulence throughout the vessel, operation at higher amplitude was clarified to be successful.

支叉管零件充液成形工艺

针对某军机支叉管类零件的结构型面复杂、曲率变化大的特点,其传统的成形方式主要采用落压成形,在成形过程中易产生起皱、破裂和表面质量差等问题。因此,提出采用被动式充液成形来加工支叉管零件,并利用有限元软件ANSYS/LS-DYNA建立有限元分析模型,对其充液成形过程进行有限元仿真模拟,研究不同压边力对充液成形的影响,从模拟结果可以得出合理吨位的压边力为300 kN。最后,通过实验研究对模拟结果进行验证,试制出合格的零件,得到支叉管零件采用被动式充液成形的最优工艺参数为压边力为300 kN、液室压力为8 MPa、压边间隙为1.05 mm,零件成形后的最大减薄率可以控制在20%以内,为支叉管零件成形找到了合适的工艺方法,利用数值仿真分析对成形复杂深腔、盒型类零件提供理论和数据支撑。

On The Analysis of Labyrinth Seal Flow Induced Vibration by Oscillating Fluid Mechanics Method

A numerical model and a solution method to analyze the labyrinth seal now induced vibration by Oscillating Fluid Mechanics Method (OFMM) are presented in this paper, including the basic equations and solution procedure to determine the oscillating velocity, pressure and the dynamic characteristic coefficients of Labyrinth seal such as the stiffness coefficients and damping coefficients. The results show that this method has the advantages of both less time cousuming and high accuracy. In addition,it can be applied to the field diagnosis of the vibration of the axis of turbomachinery system.

A new type of leak-floor flip bucket

Flip buckets are commonly used to discharge flow away from a hydraulic structure into the downstream to dissipate energy.A new leak-floor flip bucket is presented,making the ski-jump water jet a typical long-narrow nappe.Based on the model experiments and numerical simulation,the flow pattern,formation process and mechanism of the leak-floor flip bucket are studied.The results show that cross section flow shape develops from the"Y-type"to"|-type",and this is because the natural pressure difference is generated when water flows through the leak-floor area and moves transversely from both sides to the center.Different from the slit-type flip bucket with sidewall contraction,the leak-floor flit bucket makes the water jet narrow and long without high pressure on the side walls of the flip bucket.Under the same jet length condition,the maximum sidewall pressure of the slit-type is 4.67 times that of the leak-floor flip bucket.The effects of flow discharge on the jet length are less significant for the leak-floor bucket than for the slit-type bucket.