Calculating blade ring flutter

1997 ◽  
Vol 38 (5) ◽  
pp. 728-734
Author(s):  
V. E. Saren
Keyword(s):  
Blade Ring

scholarly journals A Numerical Method Used for the Simulation of Self-Excited Vibrations that Arise in the Aircraft Engine Fan Blade Ring

2020 ◽  
Vol 0 (2) ◽  
pp. 12-18
Author(s):  
Viacheslav Vladimirovich Donchenko ◽  
Vitaly Isaevich Gnesin ◽  
Lyubov Vladimirovna Kolodyzhnaya ◽  
Igor Fedorovich Kravchenko ◽  
Oleksii Vladimirovich Petrov
Keyword(s):  
Numerical Method ◽  
Aircraft Engine ◽  
Blade Ring ◽  
Fan Blade

Carotid cave aneurysms of the internal carotid artery

1989 ◽  
Vol 70 (2) ◽  
pp. 216-221 ◽  
Author(s):  
Shigeaki Kobayashi ◽  
Kazuhiko Kyoshima ◽  
Hirohiko Gibo ◽  
Sathyaranjandas A. Hegde ◽  
Toshiki Takemae ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Cavernous Sinus ◽  
Internal Carotid ◽  
Artery Aneurysm ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Blade Ring ◽  
Curved Blade ◽  
Anteroposterior View

✓ In a series of 32 surgical cases of carotid-ophthalmic artery aneurysm, seven of the lesions were located in the “carotid cave.” This special type of aneurysm is usually small and projects medially on the anteroposterior view of the angiogram. At surgery, it is located intradurally at the dural penetration of the internal carotid artery (ICA) on the ventromedial side, appears to be buried in the dural pouch (carotid cave), and is often difficult to find, dissect, and clip. The aneurysm extends into the cavernous sinus space, and the parent ICA penetrates the dural ring obliquely. An ipsilateral pterional approach was used in all 32 cases, and ring clips were used exclusively because the aneurysms were located ventromedially. Clipping was successful in five cases. All patients returned to their preoperative occupation, although vision worsened postoperatively in two cases. The technical steps required for successful obliteration of this aneurysm are summarized as follows: 1) exposure of the cervical ICA; 2) unroofing of the optic canal and removal of the anterior clinoid process; 3) exploration of the ICA around the dural ring and opening of the cavernous sinus; 4) direct retraction of the ICA and optic nerve; and 5) application of multiple ring clips to conform to the natural curvature of the carotid artery; a curved-blade ring clip is especially useful. The relevant topographic anatomy is discussed.

scholarly journals Flutter of Fan Blades in the Aircraft Engine in the Three-Dimensional Subsonic Gas Flow

2021 ◽  
pp. 13-21
Author(s):  
Vitaly Gnesin ◽  
Lyubov Kolodyazhnaya ◽  
Yuriy Bykov ◽  
Igor Kravchenko ◽  
Oleksii Petrov ◽  
...  
Keyword(s):  
Gas Flow ◽  
Operation Mode ◽  
Three Dimensional ◽  
Aircraft Engine ◽  
Three Dimensional Model ◽  
Blade Vibration ◽  
Blade Ring ◽  
Subsonic Gas Flow ◽  
The Given ◽  
Operational Development

Aeroelasticity problems arise in the different fields of technology. The accident-free operation of the airborne machines is one of the most important factors that should be taken into account during their designing and upgrading. The solution of this problem involves the implementation of many measures to provide the system reliability on the whole, including its individual elements, in particular aircraft engine, its fan whose wide-chord blades can be exposed to the wreckage due to different reasons including the aeroelastic effects, i.e. self-excited vibrations. As a result, the origination of the aeroelastic phenomenon (flutter) in design and off-design modes should be eliminated at the stage of the design and operational development of the rotor wheel that would result in a considerable increase of the level of reliability of the aircraft engine. Based on the analysis of the available methods used for the flutter prediction we can draw a conclusion that the most promising approach to the analysis of the aeroelastic behavior of the blade ring of fan is the use of the method based on the three-dimensional model of the aerodynamics and dynamics (the method used for the solution of the coupled aeroelastic problem). By solving the coupled aeroelastic problem of the nonstationary aerodynamics and elastic vibrations of the blades we can get the amplitude –frequency blade vibration spectrum for the three-dimensional gas flow, including forced vibrations and self-excided vibrations in order to increase the reliability of the blade row of turbine machines. The developed numerical method was used for the analysis of the aeroelastic behavior of the blade ring of the fan mounted in the airborne engine for the operation mode of 3520 rmp with appropriate boundary conditions at the inlet and outlet behind the ring. The computation data confirmed the origination of self-vibrations for the given fan operation mode.

Paper 39: The Flow of Wet Steam in a Turbine

1967 ◽  
Vol 182 (8) ◽  
pp. 366-373 ◽  
Author(s):  
I. I. Kirillov ◽  
R. M. Yablonik
Keyword(s):  
Considerable Effect ◽  
Condensation Process ◽  
Actual Process ◽  
Steam Turbines ◽  
Considerable Influence ◽  
Wet Steam ◽  
Blade Ring ◽  
Steam Parameters ◽  
Experimental Findings ◽  
Approximate Equations

This article considers methods of calculating condensation processes in wet steam turbines. Equations are given for determining the rate of nucleation, the growth of droplets, and the wet steam parameters. The condensation processes within the blade ring of a steam turbine are used by way of example. It is made clear that the condensation process is continuous at large enthalpy gradients. Under these conditions the theory of discontinuous condensation will not represent the actual process. Calculations based on the kinetic theory of phase change agree well with experimental findings. The constructional features of the blading which operates within the Wilson zone can have a considerable effect on the extent of the undercooling and on the size of the droplets. The trajectories of the droplets in the space between blade rings can be determined using standard approximate equations. The Coriolis force has a considerable influence on the motion of the entrained liquid within the moving blades. Under the influence of this force the liquid may move either with the flow or against it.

Paper 9: Theoretical and Experimental Studies of Wet Steam Erosion in a Counter-Rotating Radial Steam Turbine

1969 ◽  
Vol 184 (7) ◽  
pp. 16-21
Author(s):  
E. O. Söderberg ◽  
K-E. Widell
Keyword(s):  
Theoretical Model ◽  
Radial Flow ◽  
Experimental Studies ◽  
Radial Distance ◽  
Test Results ◽  
Wet Steam ◽  
Full Account ◽  
Full Size ◽  
Blade Ring ◽  
Erosion Test

Erosion test in a model counter-rotating radial flow turbine has been performed to assist in the design of a 460-MW radial flow turbine. Three rows of erosion specimens were inserted at different radial locations in the last blade ring upstream of the blades to investigate the influence of the radial distance between the stages. Results showed that small droplets were formed and that erosion diminished with increased radial spacing up to a certain distance. A theoretical model for calculating droplet trajectories, sizes, and impact velocities has been derived, taking full account of wake velocity, variable droplet drag coefficient, and atomization. The calculations explained all the experimental facts and made it possible to convert the model test results to the full-size turbine showing no risk of erosion in the latter.

Strength of adaptable blade ring of heavy-duty axial mine fans

2013 ◽  
Vol 49 (1) ◽  
pp. 118-125 ◽  
Author(s):  
N. N. Petrov ◽  
N. V. Panova
Keyword(s):  
Heavy Duty ◽  
Blade Ring

Computation of the throat area of a turbine blade ring

2015 ◽  
Vol 63 (1) ◽  
pp. 12-16
Author(s):  
B. I. Mamaev ◽  
V. L. Murashko
Keyword(s):  
Turbine Blade ◽  
Blade Ring
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