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飞碟的飞行原理研究
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作者 马永红 《价值工程》 2020年第22期182-183,共2页
飞碟的飞行原理也是用的牛顿第三定律[1],开启喷射命令下,作用力直接作用在飞碟外壳里面内壁上,只在飞行前方方向做功,不在那个方向时候关闭。并且不停旋转,那是为了在内部制造部分重力场(离心力环境),于作用力向反是带有反作用力液态... 飞碟的飞行原理也是用的牛顿第三定律[1],开启喷射命令下,作用力直接作用在飞碟外壳里面内壁上,只在飞行前方方向做功,不在那个方向时候关闭。并且不停旋转,那是为了在内部制造部分重力场(离心力环境),于作用力向反是带有反作用力液态物质在飞碟离心力作用下,不断减速回到原始位置(飞行器旋转中心),通过旋转加速均匀分布在飞行外沿管路中,等待开启,受控制中心命令而喷射。这种飞行器可以产生加速度,会不断加速,直至达到要求速度,快到目的地了再持续减速,就是反向做功就可以了,可能成为最理想太空飞行器。 展开更多
关键词 飞碟 转制造重 循环做功 废气不回收 旋力平衡
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Counter-Rotating Type Tidal Stream Power Unit Mounted on a Mono-pile 被引量:1
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作者 Yuta Usui Toshiaki Kanemoto +1 位作者 Kohei Takaki Koju Hiraki 《Journal of Energy and Power Engineering》 2014年第10期1748-1755,共8页
The authors have invented a unique counter-rotating type tidal stream power unit, which is composed of tandem propellers and a double rotational armature type generator without a stator. The front and the rear propell... The authors have invented a unique counter-rotating type tidal stream power unit, which is composed of tandem propellers and a double rotational armature type generator without a stator. The front and the rear propellers drive, as for an upstream type, the inner and the outer rotational armatures in the counter-rotating directions respectively, which keep the rotational torques counter-balanced between both propellers and armatures. This paper investigates experimentally the output and forces acting on a pile in a water channel, to get design materials of the mono-pile type tidal stream power unit. The output is maximal at the moderate rotational speed, as the same as a wind turbine. The force acting on the pile is affected by the drag, the Karman vortex and the dynamic balances of the tandem propellers, and has dominant frequencies due to not only the individual but also the interacting rotation of the front and the rear propellers. 展开更多
关键词 Tidal turbine tidal stream tandem propellers counter rotation generator ARMATURE pile.
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A 3D nonlinear finite element method for the dynamic analysis of rotating rotor with a transverse crack
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作者 WANG Shuai ZI YanYang +1 位作者 WANG Yu HE ZhengJia 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第2期219-231,共13页
A general and efficient method is presented in this paper for studying the effects of unbalance on the breathing mechanism of crack.Based on 3D finite element models combined with a nonlinear contact approach for crac... A general and efficient method is presented in this paper for studying the effects of unbalance on the breathing mechanism of crack.Based on 3D finite element models combined with a nonlinear contact approach for crack modeling, the method is free from theassumption of weight-dominance and can be used to gain deep insights into the breathing mechanism of crack. In order to greatlyreduce the computational time, a complex free-interface component mode synthesis (CMS) method is employed to reduce theorder of the model. Based on the proposed method, the effects of unbalance on the breathing mechanism of crack are discussed.Numerical results show that the unbalance can lead to significant changes in the breathing of crack, even when the unbalance force is about an order of magnitude smaller than the self-weight. Moreover, the level and orientation of the unbalance have also remarkable effects on the breathing behaviors of crack. Besides, a new universal non-steady breathing phenomenon of crack is firstly found in this paper, which denotes that the breathing speed of a crack is fluctuated over one revolution when there exists residual unbalance in the cracked rotor. 展开更多
关键词 cracked rotor breathing mechanism of crack UNBALANCE 3D finite element model model order reduction
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