Nonlinear flutter response of cylindrical shell in thermal field and supersonic gas flow

Author(s):  
G Y Baghdasaryan ◽  
M A Mikilyan ◽  
I A Vardanyan ◽  
A V Panteleev ◽  
N S Severina
Aerospace ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 103
Author(s):  
Marine Mikilyan

The work is devoted to the investigation of flutter oscillations and the stability of the closed cylindrical shell in supersonic gas flow in an inhomogeneous temperature field. It is assumed that supersonic gas flows on the outside of the shell with an unperturbed velocity U, directed parallel to the cylinder generatrix. Under the action of an inhomogeneous temperature field the shell bulges out, this deformed state is accepted as unperturbed, and the stability of this state is studied. The main nonlinear equations and relationships describing the behavior of the examined system are derived. The formulated boundary value problem is solved using the Galerkin method. The joint influence of the flow and the temperature field on the relationship between the amplitude of nonlinear oscillations of a cylindrical shell and the speed of the flowing stream is studied. The critical velocity values are calculated from the corresponding linear system and are given in tables. The numerical results show that: (a) the surrounding flow significantly affects the nature of the investigated relationship; (b) a certain interval of supersonic velocity exists where it is impossible to excite steady-state flutter oscillations (the silence zone); (c) the dependence of amplitude on the supersonic velocity can be either multivalued or single-valued.


2019 ◽  
Vol 9 (5) ◽  
pp. 285-288 ◽  
Author(s):  
G.Y. Baghdasaryan ◽  
M.A. Mikilyan ◽  
I.A. Vardanyan ◽  
P. Marzocca

2019 ◽  
Vol 488 (1) ◽  
pp. 29-35
Author(s):  
V. N. Bakulin ◽  
M. A. Konopelchev ◽  
A. Ya. Nedbay

For the first time, the aeroelastic stability equations of a composite cylindrical shell of linearly varying thickness are obtained on the basis of the bending theory of orthotropic shells for a shell subjected to axial forces and supersonic gas flow. The solution of the equations is assumed of the form of a trigonometric series in the axial coordinate. The problem is reduced to an infinite system of algebraic equations by the Bubnov-Galerkin method. The obtained characteristic equation is approximated by the Lagrange polynomial, whose stability is investigated with the use of the Routh-Hurwitz criterion. As a numerical example, the effect of the thickness gradient, structural damping and axial force on the critical velocity for a composite shell of linearly varying thickness in supersonic gas flow is shown. The refinement in the value of the critical velocity resulting from the use of the suggested model is about 35% as compared to the results for a shell of averaged constant thickness. This indicates the relevance of this model for aircraft weight optimization. The suggested approach expands the range of problems to be solved and allows for the analysis of the aeroelastic stability for orthotropic cylindrical shells of linearly varying thickness in supersonic gas flow.


2015 ◽  
Vol 799-800 ◽  
pp. 660-664
Author(s):  
Lelya Khajiyeva ◽  
Askhat Kudaibergenov

In the paper nonlinear vibrations of a drill string’s section in a supersonic gas flow are studied. The drill string is modelled in the form of a circular cylindrical shell under the effect of a longitudinal compressing load and torque. In contrast to the previous research, pressure of an unperturbed gas is defined nonlinearly in the third approximation. The eighth order partial differential equation describing the motion of the shell reduces to a nonlinear system of ordinary differential equations with application of the Bubnov-Galerkin technique. An implicit Runge-Kutta method is applied to construct modes of vibrations.


2017 ◽  
Vol 30 (5) ◽  
pp. 04017037 ◽  
Author(s):  
Gevorg Baghdasaryan ◽  
Marine Mikilyan ◽  
Rafayel Saghoyan

2018 ◽  
Vol 49 (4) ◽  
pp. 415-427
Author(s):  
Igor Ivanovich Lipatov ◽  
Vladimir Yakovlevich Neiland

1954 ◽  
Vol 5 (1) ◽  
pp. 1-6
Author(s):  
W A Mair
Keyword(s):  
Gas Flow ◽  

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