The traditional jet fans have equipped with the tandem impellers and the exclusive motors, and such designs are associated with the expensive initial cost. This serial research proposes how to simplify the fan profile...The traditional jet fans have equipped with the tandem impellers and the exclusive motors, and such designs are associated with the expensive initial cost. This serial research proposes how to simplify the fan profile for reducing the initial cost without the performance deteriorations. The paper discusses the effects of the hub profiles installed in the traditional/commercial jet fan, on the performances in the several type single-stage work. The hub with the long tail corn gives the best efficiency, and not only the stay vanes but also the cooling fins deteriorate more or less the performances, accompanying the impeller works as follows. The efficiency at the reverse rotation of the original impeller, namely at the flow condition running from the outlet to the inlet, is doubtlessly lower than one at the original rotation. The unique cascade, where the leading and the trailing edges of the blade are alternated in the tangential direction, was prepared in anticipation of improving the performances. These results advise the desirable profile of the jet fan equipped with the single-stage impeller, and the numerical simulation provides the optimum blade profile for the bidirectional flow.展开更多
To suppress the cavitation in the impellers and to make the turbo-pump lives longer, the inducer was separated from the main impeller and both impellers were driven independently. The performance of the pump and the f...To suppress the cavitation in the impellers and to make the turbo-pump lives longer, the inducer was separated from the main impeller and both impellers were driven independently. The performance of the pump and the flow conditions around the impellers were investigated experimentally and the following results were obtained. （1）The main impeller contributes to the flow interaction between the inducer and the main impeller. （2）The rotational speeds of both impellers can be controlled independently in order to suppress simultaneously the cavitation not only in the main impeller, but also in the inducer.展开更多
The shaft-less impeller of the centrifugal pump, which is driven by the magnetic induction, was developed. Theimpeller rotates under the floating condition without any control device. The floating condition of the imp...The shaft-less impeller of the centrifugal pump, which is driven by the magnetic induction, was developed. Theimpeller rotates under the floating condition without any control device. The floating condition of the impeller isrealized by utilizing the pressure in pump casing. The pump performance and the rotational behavior of the impellerwere investigated experimentally. It has found that the floating position of the impeller become quite unstablein a partial flow rate operation. And the pressure distribution at the casing wall affects the rotational posture ofthe impeller. This paper presents the effect of the casing treatment on the rotational posture of the impeller and thepressure distribution. The reasonable casing treatment is available for the stable rotational posture of the impeller.展开更多
文摘The traditional jet fans have equipped with the tandem impellers and the exclusive motors, and such designs are associated with the expensive initial cost. This serial research proposes how to simplify the fan profile for reducing the initial cost without the performance deteriorations. The paper discusses the effects of the hub profiles installed in the traditional/commercial jet fan, on the performances in the several type single-stage work. The hub with the long tail corn gives the best efficiency, and not only the stay vanes but also the cooling fins deteriorate more or less the performances, accompanying the impeller works as follows. The efficiency at the reverse rotation of the original impeller, namely at the flow condition running from the outlet to the inlet, is doubtlessly lower than one at the original rotation. The unique cascade, where the leading and the trailing edges of the blade are alternated in the tangential direction, was prepared in anticipation of improving the performances. These results advise the desirable profile of the jet fan equipped with the single-stage impeller, and the numerical simulation provides the optimum blade profile for the bidirectional flow.
文摘To suppress the cavitation in the impellers and to make the turbo-pump lives longer, the inducer was separated from the main impeller and both impellers were driven independently. The performance of the pump and the flow conditions around the impellers were investigated experimentally and the following results were obtained. （1）The main impeller contributes to the flow interaction between the inducer and the main impeller. （2）The rotational speeds of both impellers can be controlled independently in order to suppress simultaneously the cavitation not only in the main impeller, but also in the inducer.
文摘The shaft-less impeller of the centrifugal pump, which is driven by the magnetic induction, was developed. Theimpeller rotates under the floating condition without any control device. The floating condition of the impeller isrealized by utilizing the pressure in pump casing. The pump performance and the rotational behavior of the impellerwere investigated experimentally. It has found that the floating position of the impeller become quite unstablein a partial flow rate operation. And the pressure distribution at the casing wall affects the rotational posture ofthe impeller. This paper presents the effect of the casing treatment on the rotational posture of the impeller and thepressure distribution. The reasonable casing treatment is available for the stable rotational posture of the impeller.
