Due to no design guidelines available for the hubless propeller,based on the relative inflow velocities together with blade root strength considerations, the Ka –series propeller’s blade geometry was re-designed with an inversion of the thickness distribution of the sections. Accordingly,the blade geometry model for hubless rim-driven propulsors was designed,then three types of hubless rim-driven propulsors’ models were established and calculated numerically. The results show that thrust coefficients and torque coefficients for hubless rim-driven propulsors are similar to the ducted Propeller’s. Due to no hub, with the new thruster the hub-vortex is avoided and the cavitation minimized.
Characteristics of field failure data are analyzed in this paper. The failure data and sales
record of LZL-type mass flowmeter are used to infer life distribution of this conduct. The lines can be
fitted in coordinates of six distribution using least square and the residual sum of squares are
compared, the minimum correspond is the best distribution type. The results show that the life
distribution style of this conduct is the two parameter exponential distribution, which is the base to
analyze and predict failure development, research failure mechanism and draw up maintenance
policy.
Flow inside the diesel nozzle is crucial to spray, combustion, and emissions. This work aimed to improve the understanding of effects of internal fuel-flow on diesel spray, especially the special string cavitating flow. Optical experiments were employed for characterizing the formation of string cavitation inside the transparent scaled-up tapered diesel orifices. Simultaneously, the corresponding evolution of spray cone angles were obtained. Results show that there were two origins of the string cavitation, which were originated from inlet and outlet of the orifice, respectively. Moreover, there were two typical development processes of the string cavitation between hole and hole, which were defined as type-A and type-B string cavitation. Furthermore, effects of string cavitation were analyzed: it could trigger the geometry-induced cavitation and make a sharp increase of spray cone angle. Finally, the relationships between the occurrence regularity of string cavitation, the needle lift and the injection pressure were revealed by comparison of different needle lifts and different injection pressures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.