Wyniki wyszukiwania - BazTech

1

Implementing SimulationX in the modelling of marine shafting steady state torsional vibrations

Vulić Nenad, Bratić Karlo, Lalić Branko, Stazić Ladislav

Polish Maritime Research

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2021

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nr 2

63--71

EN

Marine propulsion shafting systems are exposed to torsional vibrations originating from excitations in their prime movers and propellers. It is essential to analyse their steady state response in the earliest stage of ship design. The paper describes the implementation of SimulationX software based upon simulation modelling for these calculations. This software can be used either by the design office of the shipyard or by the classification society for verification within the plan approval phase. Some specifics of the input data preparation are briefly discussed. In addition, the simulation results depend on the modelling approach chosen. For these reasons, the real two-stroke Diesel engine ship propulsion system was chosen and several different models were implemented for system modelling. SimulationX calculation results are compared with those of two well-known and field-proven programs that use an analytical approach. Finally, the results are compared with the measurements performed on the actual newly built ship. Discussion reviews the selected SimulationX model, and its verification and validation in the case of engine cylinders with normal ignition.

2

Inertial elastic instability of rotating nano disks

Güven Uğur

Journal of Theoretical and Applied Mechanics

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2019

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Vol. 57 nr 4

853--858

EN

In this work, the static inertial-elastic instability of rotating nano disks is investigated with the centrifugal force formulation considering the radial displacement. Thus, Brunelle’s previous local solution is generalized by using Eringen’s nonlocal elasticity theory. The variations of critical rotation speeds with the nonlocal scale parameter are illustrated under different boundary conditions. It is seen that the critical rotation speeds decrease as the nonlocal scale parameters increase for all cases. Also, it is remarkable that the presented results are affected significantly from the boundary conditions.

3

The dynamics modeling and simulation for coupled double-rotor spindle system of high speed grynder

Hou Y., Wang S., Han Z.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

25--28

EN

This study was focused on the theoretical modeling and numerical simulation about the dynamic characteristics of coupled double-rotor spindle system of high speed grinder. The critical speeds of first three orders, the modes of variation and other dynamic characteristic parameters of the spindle system were analyzed and calculated. The results showed that the critical speeds of coupled double-rotor system were arranged in a similar increasing order as to those of each single rotor. It was thus indicated that the critical speeds of each order for coupled double-rotor system corresponded to those of single rotor. Furthermore, the main vibration modes of double-rotor system at each order were analyzed. The results indicated that vibration mode of each order of double rotors was the superimposition of the vibration mode of each single rotor. At variable critical speeds, the vibration mode of each single rotor in the system varied in its extent. If the critical speed of double-rotor system was close to that of a single rotor, then the superimposition of vibration modes of single rotors would become more significant under coupling state.

PL

W pracy położono nacisk na modelowanie teoretyczne i symulację numeryczną charakterystyk dynamicznych systemu wrzeciona ze sprzężonym podwójnym rotorem w wiertarce dużej szybkości, Przeanalizowano i obliczono szybkości krytyczne trzech pierwszych rzędów, typy wibracji i inne parametry charakterystyk dynamicznych systemu wrzeciona. Wykazano, że szybkości krytyczne systemu z rotorem podwójnym odpowiadają szybkości krytycznej odpowiednika z rotorem pojedynczym. Natomiast typy wibracji każdego rzędu rotora podwójnego są superpozycją typów wibracji pojedynczych rotorów. Jeśli szybkość krytyczna systemu z podwójnym rotorem jest bliska tej, jaką ma pojedynczy rotor, typy wibracji pojedynczych rotorów stają się bardziej znaczące pod wpływem stanu sprzężenia.

4

Rascetnye i eksperimental'nye issledovania dinamiceskih harakteristik rotorov centrobeznyh nasosov s opornymi podsipnikami skol'zenia na perekacivaemaj srede

Tsoma O., Los D., Orlov O.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne

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2008

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Z. 10, Vol. 1

125-134

EN

Results of design investigations of free flexural vibrations of multistage centrifugal ring section pumps rotors with inboard journal bearings on pumped medium and results of experimental investigations for determination of critical speeds of these pumps rotors are given. The investigation were carried out using various design models and design methods and various measuring systems. They showed that rotors of the pumps designs being investigated were flexible.

5

Osobennosti proektirovania centrobeznyh kompressorov c aktivnymi magnitnymi podsipnikami

Gadiaka V., Panenko V.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne

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2008

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Z. 10, Vol. 1

181-187

EN

Some features of dynamic calculations at design are considered, and also the problems, related to balancing of rotors of centrifugal compressors which the active magnetic bearing are used.