Experimental investigation of the stability of reinforced cylindrical shells under high pressures

1969 ◽  
Vol 5 (5) ◽  
pp. 473-476
Author(s):  
A. I. Manevich
Keyword(s):  
Experimental Investigation ◽  
High Pressures ◽  
Cylindrical Shells ◽  
The Stability

Experimental investigation of the stability of corrugated cylindrical shells

1992 ◽  
Vol 28 (3) ◽  
pp. 176-179
Author(s):  
V. M. Muratov ◽  
A. T. Tubaivskii ◽  
N. T. Bobel'
Keyword(s):  
Experimental Investigation ◽  
Cylindrical Shells ◽  
The Stability

Experimental investigation of the stability of cylindrical shells with elastic frames

1980 ◽  
Vol 16 (10) ◽  
pp. 867-872
Author(s):  
�. V. Antonenko ◽  
V. N. Zogol' ◽  
V. V. Mikhailov ◽  
V. P. Shirshlin
Keyword(s):  
Experimental Investigation ◽  
Cylindrical Shells ◽  
The Stability

Analysis of the ‘Friction Factor Jump’ Phenomenon in Hole-Pattern Seals

2013 ◽  
Author(s):  
Aarthi Sekaran ◽  
Gerald Morrison
Keyword(s):  
Experimental Investigation ◽  
High Pressure ◽  
Shear Layer ◽  
Friction Factor ◽  
Pressure Fluctuation ◽  
High Pressures ◽  
Sudden Change ◽  
Flow Models ◽  
The Difference ◽  
The Stability

Hole-pattern and honeycomb seals are used to replace labyrinth seals in turbomachinery that are experiencing vibration problems, such as high pressure gas compressors. Computer simulations used to investigate the stability of a rotordynamic system require information about the stiffness, damping, and added mass generated by bearings and seals. These codes typically use bulk flow models for the fluid flow inside the bearings and seals which require empirical information about how the friction factor and leakage rate vary with rotor speed and pressure drop across the seal. Historically, experimental facilities were constructed to provide empirical data which were then used in the rotordynamic models. Ha et al (1992) observed a sudden change in the flow rate and resulting friction factor in a honeycomb seal as the pressure differential across the seal increased. This ‘friction factor jump’ was attributed to the shear flow over a seal cavity changing from a dominant normal mode to a dominant feedback mode. This was confirmed through pressure spectra showing that indeed, the shear layer instability mode changed and the frequencies present compared to predicted values. A similar effect has recently been observed in hole-pattern seals operating at high pressures, 84 bar (1200 psi). However, the pressure fluctuation spectra did not confirm the same mode change observed by Ha. The friction factor changed a by factor of around three in this instance which can drastically change the stability of the rotating system. This high pressure flow has a higher Reynolds number due to the high pressures which may explain the difference. An experimental investigation has confirmed the presence of the “friction factor jump” and that there is a change in the pressure fluctuation spectra. Further experimental investigation coupled with Large Eddy Simulation (LES) of the flow field have confirmed there is a change in the shear layer over the cavity but not the same as observed by Ha. Comparisons between the experimental and computational results are made along with an explanation of the flow phenomena.

Buckling of Circular Cylindrical Shells Using a Displacement Function

1974 ◽  
Vol 96 (4) ◽  
pp. 1322-1327
Author(s):  
Shun Cheng ◽  
C. K. Chang
Keyword(s):  
Boundary Conditions ◽  
Axial Compression ◽  
Cylindrical Shells ◽  
External Pressure ◽  
Displacement Function ◽  
Combined Loading ◽  
Trial Solution ◽  
Governing Differential Equation ◽  
Circular Cylindrical Shells ◽  
The Stability

The buckling problem of circular cylindrical shells under axial compression, external pressure, and torsion is investigated using a displacement function φ. A governing differential equation for the stability of thin cylindrical shells under combined loading of axial compression, external pressure, and torsion is derived. A method for the solutions of this equation is also presented. The advantage in using the present equation over the customary three differential equations for displacements is that only one trial solution is needed in solving the buckling problems as shown in the paper. Four possible combinations of boundary conditions for a simply supported edge are treated. The case of a cylinder under axial compression is carried out in detail. For two types of simple supported boundary conditions, SS1 and SS2, the minimum critical axial buckling stress is found to be 43.5 percent of the well-known classical value Eh/R3(1−ν2) against the 50 percent of the classical value presently known.

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