scholarly journals Self-vibrations of a functionally graded nanocomposite cylindrical shell in a supersonic gas flow

2019 ◽  
Vol 2019 (2) ◽  
pp. 48-59
Author(s):  
K.V. Avramov ◽  
Keyword(s):  
Cylindrical Shell ◽  
Gas Flow ◽  
Functionally Graded ◽  
Supersonic Gas Flow

scholarly journals Thermoelastic Response of Closed Cylindrical Shells in a Supersonic Gas Flow

Aerospace ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 103
Author(s):  
Marine Mikilyan
Keyword(s):  
Cylindrical Shell ◽  
Temperature Field ◽  
Gas Flow ◽  
Nonlinear Oscillations ◽  
Supersonic Velocity ◽  
Inhomogeneous Temperature ◽  
Inhomogeneous Temperature Field ◽  
Supersonic Gas Flow ◽  
The Stability ◽  
The Galerkin Method

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.

scholarly journals Thermoelastic stability of closed cylindrical shell in supersonic gas flow

2019 ◽  
Vol 9 (5) ◽  
pp. 285-288 ◽  
Author(s):  
G.Y. Baghdasaryan ◽  
M.A. Mikilyan ◽  
I.A. Vardanyan ◽  
P. Marzocca
Keyword(s):  
Cylindrical Shell ◽  
Gas Flow ◽  
Closed Cylindrical Shell ◽  
Supersonic Gas Flow

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

2020 ◽  
Vol 927 ◽  
pp. 012022
Author(s):  
G Y Baghdasaryan ◽  
M A Mikilyan ◽  
I A Vardanyan ◽  
A V Panteleev ◽  
N S Severina
Keyword(s):  
Cylindrical Shell ◽  
Gas Flow ◽  
Thermal Field ◽  
Nonlinear Flutter ◽  
Supersonic Gas Flow

scholarly journals Aeroelastic stability of a cylindrical shell of linearly varying thickness

2019 ◽  
Vol 488 (1) ◽  
pp. 29-35
Author(s):  
V. N. Bakulin ◽  
M. A. Konopelchev ◽  
A. Ya. Nedbay
Keyword(s):  
Cylindrical Shell ◽  
Critical Velocity ◽  
Gas Flow ◽  
Constant Thickness ◽  
Aeroelastic Stability ◽  
Suggested Approach ◽  
Varying Thickness ◽  
Axial Forces ◽  
Supersonic Gas Flow ◽  
Orthotropic Shells

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.

Analysis of Nonlinear Vibrations of a Cylindrical Shell in a Supersonic Gas Flow

2015 ◽  
Vol 799-800 ◽  
pp. 660-664
Author(s):  
Lelya Khajiyeva ◽  
Askhat Kudaibergenov
Keyword(s):  
Cylindrical Shell ◽  
Gas Flow ◽  
Nonlinear Vibrations ◽  
Circular Cylindrical Shell ◽  
Drill String ◽  
Order Partial Differential Equation ◽  
Eighth Order ◽  
The Third ◽  
Runge Kutta Method ◽  
Supersonic Gas Flow

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.

TO THE THEORY OF UNSTEADY SEPARATION AND INTERACTION OF BOUNDARY LAYER WITH SUPERSONIC GAS FLOW

2018 ◽  
Vol 49 (4) ◽  
pp. 415-427
Author(s):  
Igor Ivanovich Lipatov ◽  
Vladimir Yakovlevich Neiland
Keyword(s):  
Boundary Layer ◽  
Gas Flow ◽  
Unsteady Separation ◽  
Supersonic Gas Flow

scholarly journals Vibration analysis of a sandwich cylindrical shell in hygrothermal environment

2021 ◽  
Vol 10 (1) ◽  
pp. 414-430
Author(s):  
Chunwei Zhang ◽  
Qiao Jin ◽  
Yansheng Song ◽  
Jingli Wang ◽  
Li Sun ◽  
...  
Keyword(s):  
Cylindrical Shell ◽  
Natural Frequency ◽  
Equations Of Motion ◽  
Single Layer ◽  
Functionally Graded ◽  
Sandwich Shell ◽  
Continuous Change ◽  
Multilayered Structures ◽  
Cylindrical Sandwich Shell ◽  
Vibrational Behavior

Abstract The sandwich structures are three- or multilayered structures such that their mechanical properties are better than each single layer. In the current research, a three-layered cylindrical shell including a functionally graded porous core and two reinforced nanocomposite face sheets resting on the Pasternak foundation is used as model to provide a comprehensive understanding of vibrational behavior of such structures. The core is made of limestone, while the epoxy is utilized as the top and bottom layers’ matrix phase and also it is reinforced by the graphene nanoplatelets (GNPs). The pattern of the GNPs dispersion and the pores distribution play a crucial role at the continuous change of the layers’ properties. The sinusoidal shear deformation shells theory and the Hamilton’s principle are employed to derive the equations of motion for the mentioned cylindrical sandwich shell. Ultimately, the impacts of the model’s geometry, foundation moduli, mode number, and deviatory radius on the vibrational behavior are investigated and discussed. It is revealed that the natural frequency and rotation angle of the sandwich shell are directly related. Moreover, mid-radius to thickness ratio enhancement results in the natural frequency reduction. The results of this study can be helpful for the future investigations in such a broad context. Furthermore, for the pipe factories current study can be effective at their designing procedure.

Supersonic gas flow

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