船舶蒸汽动力装置燃油压力调节系统的性能仿真与改进建议

由于船舶蒸汽动力装置燃油系统工作压力较高，且变化剧烈，容易发生管路密封垫片处崩出等事故，这将直接导致该动力单元瘫痪。针对该类故障，提出改进建议，并应用MATLAB／Simulink仿真工具对燃油系统进行定性、定量分析，对所提出的改进方法进行比较验证。     

Numerical simulation of hydrogen arcjet thruster with coupled sheath model

In the present work, a complete 2D chemical and thermal non-equilibrium numerical model coupled with a relatively simple sheath model is developed for hydrogen arcjet thruster. Conduction heat transfer in the anode wall is also included in the model. The operating voltages predicted by the model are compared with those in the literature and are found to be in close agreement. Power distributions for the various operating conditions are obtained, anode radiation loss primarily determines the thruster efficiency. Higher thruster efficiency was found to be associated with longer arc length. At cathode ion diffusion contribution dominates except at low input current where thermo-field electron current is dominant.     

基于LabVIEW的高速数据采集系统设计

针对卫星电推进分系统地面测试设备建设方案,开发了配套的数据采集存储系统,其实质上是一个电推进试验的总控平台。采用LabVIEW语言建立上位机的数据采集,能够在前台监控计算机提供人机界面,实现数据的采集、保存,各种波形显示,监测数据和试验状态,在线判读,报警等功能。实际运行表明,该系统数据采集过程稳定、可靠,达到了设计要求。     

Modelling and simulation of a zero-emission hybrid power plant for a domestic ferry

This paper presents a simulation tool for marine hybrid power-plants equipped with polymer exchange membrane fuel cells and batteries. The virtual model, through the combination of operational data and dynamically modelled subsystems, can simulate power-plants of different sizes and configurations, in order to analyze the response of different energy management strategies. The model aims to replicate the realistic behavior of the components included in the vessel's grid, to asses if the hardware selected by the user is capable of delivering the power set-point requested by the energy management system. The model can then be used to optimize key factors such as hydrogen consumption. The case study presented in the paper demonstrates how the model can be used for the evaluation of a retrofitting operation, replacing a diesel electric power-plant with fuel cells and batteries. The vessel taken into consideration is a domestic ferry, operating car and passenger transport in Denmark. The vessel is outfitted with a diesel electric plant and an alternative hybrid power-plant is proposed. The hybrid configuration is tested using the model in a discrete time-domain.     

螺旋桨负载永磁同步电机直接转矩控制系统研究

为了研究空间矢量调制策略对大功率永磁同步电机在螺旋桨负载特性下变频调速性能的影响,通过对直接转矩控制变频调速和螺旋桨负载特性理论的分析,结合螺旋桨敞水特性曲线,得到螺旋桨推力系数Kp和扭矩系数Km分别与进速比J之间的函数关系.提出了推力系数和扭矩系数的计算方法,建立了螺旋桨负载和永磁推进电机直接转矩控制的仿真模型.仿真结果表明,直接转矩控制系统中永磁推进电机转速动态响应快,转速稳定后电磁转矩与螺旋桨旋转产生的负载转矩相等.与实测电机运行数据比较可知,不同转速下仿真得到的电机转矩值与实测值相一致,验证了该模型的有效性.     

某船双机并车主推进系统集成设计研究

根据某船主推进系统集成项目,从主推进系统设计、主推进系统计算校核和主推进控制系统设计三个方面论述主推进系统,尤其是双机并车主推进系统的集成设计.设计结果显示,所设计的主推进系统满足设计要求,目前该主推进系统已进入安装调试阶段.该船主推进集成设计方法可为其他船舶,特别是双机并车船舶主推进系统集成设计提供借鉴和参考.     

Experimental Investigation of the Properties of an Acoustic Wave Induced by Laser Ablation of a Solid Target in Water-Confined Plasma Propulsion

Acoustic waves generated in nanosecond pulsed-laser ablation of a solid target in both air and water-confined environments were measured experimentally. It was found that the amplitude of the acoustic wave tended to decrease with an increase in water thickness. The waves were analyzed by means of fast Fourier transform. It was shown that there are several frequency components in the acoustic waves with the dominant frequency shifting from high frequency to low frequency as the thickness of the water layer increases. Furthermore, strong acoustic pressure led to enhancement of the coupling of the laser energy to the target in laser plasma propulsion.     

同步感应电磁推进系统中电枢制造材料的选择

对同步感应电磁推进系统进行了理论分析并建立了单级系统的电路模型,直接建立了电枢制造材料的基本物理参数与电枢感应涡流之间的联系.通过有限元仿真软件模拟比较了不同材质的电枢对电枢受力及电枢加速速度的影响,计算了不同材质电枢对整体系统能量转化效率的影响.结果表明:电枢制造材料的选择将影响电枢的受力方式、整体系统的能量转化率及有效加速载荷的质量,铝制材料在几种电枢制造材料中表现最优.以上分析可为同步感应型电磁推进系统的电枢设计提供参考.     

关于电力推进系统的实时仿真

本文分析了现有电力系统仿真软件,并针对含有电力电子装置的电力推进系统仿真,选取RT LAB实时仿真软件作为平台,用实例检验电力推进系统实时数字仿真的情况.     

涡轮叶片非对称扇形气膜孔冷却特性数值研究

针对涡轮导向叶片吸力面和压力面上特定位置上的单排气膜孔,在吹风比为0.44～2.67范围内,数值研究非对称扇形气膜孔的冷却特性。基准对称扇形孔侧向扩展角为20°,后向扩展角为10°。研究结果表明,在扇形总扩展角相等的条件下,非对称型扇形气膜孔的气膜出流穿透能力与对称型扇形气膜孔基本相当,但气膜出流侧向覆盖范围较对称型扇形气膜孔有一定程度的改善,在高吹风比下扇形气膜孔侧向扩展角的影响较为显著。相对而言,非对称扇形气膜孔改善气膜冷却的效果在涡轮叶片压力面侧能得到更好的体现。