On the Self-Propelled Motion of a Rigid Body in a Viscous Liquid and on the Attainability of Steady Symmetric Self-Propelled Motions

2002 ◽  
Vol 4 (4) ◽  
pp. 285-326 ◽  
Author(s):  
A. L. Silvestre
Keyword(s):  
2013 ◽  
Vol 341 (11-12) ◽  
pp. 760-765 ◽  
Author(s):  
Giovanni P. Galdi ◽  
Giusy Mazzone ◽  
Paolo Zunino
Keyword(s):  

Author(s):  
Atsuhiko Shintani ◽  
Tomohiro Ito ◽  
Chihiro Nakagawa

Abstract In this study, the effectiveness of coaxial circular cylinders containing a highly viscous liquid in annular spaces for reduction of rocking motion of a free-standing structure is investigated both analytically and experimentally. First, an analytical model of coupled rocking and sliding motions of a free-standing structure, including the coaxial circular cylinders, subjected to seismic input was derived. The free-standing structure was modeled as a free-standing rigid body. The cylinders were attached to the bottom of the rigid body as a damping device. We then experimentally derived the friction coefficients, inertia moments, and a damping coefficient in the rotating direction. Furthermore, using these parameters, the effectiveness of this system in suppressing the rocking motion is investigated analytically. The proposed method was determined to be very effective in suppressing the rocking motion of a rigid body subjected to a seismic input by the experiment.


2019 ◽  
pp. 129-133
Author(s):  
A.V. Machnev ◽  
O.N. Kukharev ◽  
O.Yu. Machneva ◽  
V.A. Machnev ◽  
P.N. Horev ◽  
...  

Применение протравливателей семян способствует повышению их полевой всхожести, снижению головневых заболеваний и корневых гнилей. Опыт эксплуатации протравливателей в зерносеющих хозяйствах показал, что в Российской Федерации наибольшее распространение получили самоходные протравливатели камерного типа ПС-20АМ01, Mobitox Super, ПСК-15. Недостатки этих машин выражаются в невозможности проведения качественного протравливания на площадках с углом наклона более 7 градусов и при работе машины при производительности в диапазоне от 60 до 100 от базовой. Кроме того, повышенные влажность семян после протравливания (по агротехническим требованиям АТТ не более 1 ) и дробление семян несколько снижают эффективность применения камерных протравливателей. Целью исследований являлось повышение качества протравливания семян за счет применения двухдискового распределяющего и двухуровневого отражающего устройств. Для чего сравнительные исследования протравливателя Mobitox Super, оснащенного двухдисковым распределяющим устройством и двухуровневым отражающим устройством семян, проводили с базовым вариантом Mobitox Super в ООО Русское поле Сердобского района Пензенской области на обработке семян озимой пшеницы Бирюза комбинированным инсектофунгицидным протравителем семян Селект Макс с нормой расхода препарата 1,7 л/т. Установлено, что в диапазоне от 30 до 150 мм открытия заслонки лепесткового дозатора разработанного камерного самоходного протравливателя качество протравливания семян значительно увеличивается в сравнении с серийно-выпускаемым Mobitox Super и увеличивается его производительность до 2,1 т/ч.The use of seed dressers improves their field germination, reduces smut diseases and root rot. The experience of the use of dressing agents in grain-sowing farms showed that the self-propelled seed dressers PS-20AM01, Mobitox Super, PSK-15 are most widely used in the Russian Federation.The disadvantages of these machines are expressed in the impossibility of conducting high-quality dressing on sites with an inclination angle of more than 7 degrees and when the machine is operating at a capacity in the range from 60 to 100 of the base. In addition, the increased moisture content of the seeds after dressing (according to the agrotechnical requirements of perfectly rigid body (PRB) - no more than 1 ) and the crushing of seeds somewhat reduce the effectiveness of using chamber dressers. The aim of the research was to improve the quality of seed dressing through the use of a two-disk distributing and a two-level reflecting devices. We conducted comparative studies of the Mobitox Super seed dresser, equipped with a two-disk distributor and a two-level seed reflector, with the basic version of Mobitox Super. The studies were carried out in the OOO Russkoye Polye of Serdobsky district of the Penza region on the treatment of winter wheat Biryuza seeds with a combined insectofungic seed dresser Select Max with a consumption rate of 1.7 l/t. It was established that in the range from 30 to 150 mm of opening the spade-type dispenser flap of the developed chamber self-propelled seed dresser, the quality of seed dressing significantly increased and its productivity increased to 2.1 t/h in comparison with the commercially available Mobitox Super.


Author(s):  
Ana L. Silvestre ◽  
Takéo Takahashi

We study the motion of a rigid body with a cavity filled with a viscous liquid. The main objective is to investigate the well-posedness of the coupled system formed by the Navier–Stokes equations describing the motion of the fluid and the ordinary differential equations for the motion of the rigid part. To this end, appropriate function spaces and operators are introduced and analysed by considering a completely general three-dimensional bounded domain. We prove the existence of weak solutions using the Galerkin method. In particular, we show that if the initial velocity is orthogonal, in a certain sense, to all rigid velocities, then the velocity of the system decays exponentially to zero as time goes to infinity. Then, following a functional analytic approach inspired by Kato's scheme, we prove the existence and uniqueness of mild solutions. Finally, the functional analytic approach is extended to obtain the existence and uniqueness of strong solutions for regular data.


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