空调系统

按照《苏联海船卫生规则》,在各区域营运的浮动设施必须设置舒适性空调系统(CKB).它们是通风系统的进一步发展,其区别在于:进入舱室的空气应按外界条件经受加热或冷     

完全数字阀——充分利用液压伺服系统

步进电机和单级阀组成的数字伺服阀提高了精度和性能。     

高速柴油机的电子喷油定时控制装置

由于发动机的发展,高速柴油机的喷油定时,将由精确的电子控制来取代目前使用的离心式定时器的控制。不过,到目前为上,这样的电子控制装置仍处于试验室的试验阶段。虽然一些制造厂家也发表了一些有关的文章,但真正能供重型车辆用的喷油定时控制装置至今尚未问世。 事实上,在一个重型车辆和寿命周期的总费用中,燃油费用所占的比重是非常大的。如果有一种可降低油耗的装置,那么可以肯定,是会受到用户欢迎的。基于上述考虑,笔者才试图设计出一种新型的燃油喷射控制装置。 这种新的燃油喷射控制装置系采用微型计算机和具有专用油路的液压执行器随发动机转速和负荷的变化来控制最佳喷油定时。 本文叙述了该装置的结构、工作原理、技术性能及市场反应等。     

预示旋转机械损伤的振动监控设备

用测量振动来预示旋转机械损伤的有关文章已发表了很多,从手握的振动计到借助于计算机的监控系统都获得了令人鼓舞的结果。本文着眼于机械振动监控方面的设备,特别着重于信号分析。该设备比较容易掌握,能够对机械损伤做出更精确的预测。     

高速柴油机气缸内火焰温度的实验与测定

火焰温度随时间变化的过程可以显示出柴油机燃烧的特性。这不仅与反应区域的放热情况有关,同时也与碳烟的形成和烧失,氧化氮的产生以及热幅射有关。试验确定火焰温度的一种可取的方法是测量碳烟发光火焰的幅射。这时在二段狭窄的波长范围内测量幅射强度。     

离心泵的转子振动和液体压力脉动研究

作者通过研究试验证明,为了降低转子振动和泵出口的液体压力脉动的幅度,可以采用管状滤器。     

采用微气泡缩减高速船拖曳阻力(英文)

Ship hull form of the underwater area strongly influences the resistance of the ship.The major factor in ship resistance is skin friction resistance.Bulbous bows,polymer paint,water repellent paint(highly water-repellent wall),air injection,and specific roughness have been used by researchers as an attempt to obtain the resistance reduction and operation efficiency of ships.Micro-bubble injection is a promising technique for lowering frictional resistance.The injected air bubbles are supposed to somehow modify the energy inside the turbulent boundary layer and thereby lower the skin friction.The purpose of this study was to identify the effect of injected micro bubbles on a navy fast patrol boat(FPB) 57 m type model with the following main dimensions:L=2 450 mm,B=400 mm,and T=190 mm.The influence of the location of micro bubble injection and bubble velocity was also investigated.The ship model was pulled by an electric motor whose speed could be varied and adjusted.The ship model resistance was precisely measured by a load cell transducer.Comparison of ship resistance with and without micro-bubble injection was shown on a graph as a function of the drag coefficient and Froude number.It was shown that micro bubble injection behind the mid-ship is the best location to achieve the most effective drag reduction,and the drag reduction caused by the micro-bubbles can reach 6%-9%.