Determining unsteady aerodynamic forces for three-dimensional plate cascade in subsonic gas flow

1971 ◽  
Vol 2 (6) ◽  
pp. 13-18 ◽  
Author(s):  
D. N. Gorelov ◽  
L. V. Dominas
Author(s):  
I. Sladojevic´ ◽  
E. P. Petrov ◽  
A. I. Sayma ◽  
M. Imregun ◽  
J. S. Green

The paper summarises the results of a study investigating the correlation between the aerodynamic blade-to-blade coupling in mistuned bladed disc assemblies and the level of forced response. The focus was placed on the torsional mode of vibration, where blades’ coupling through the disc is weak, exposing the effects of aerodynamic coupling. The forced response of a large number of mistuned discs was computed, using whole-annulus finite element (FE) models. The unsteady aerodynamic forces that act upon the disc were calculated using a three-dimensional Reynolds-averaged Navier-Stokes CFD code. The results show the difference in response with and without aerodynamic coupling, exposing higher blade-to-blade interaction in the latter case. The statistical results show the change of the forced response distribution curves with the introduction of aero-coupling and their deviation from Gaussian distribution.


Author(s):  
Vitaly Gnesin ◽  
Lyubov Kolodyazhnaya ◽  
Yuriy Bykov ◽  
Igor Kravchenko ◽  
Oleksii Petrov ◽  
...  

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.


1983 ◽  
Author(s):  
A. BALAKRISHNAN ◽  
C. LOMBARD ◽  
W.C. DAVY

1990 ◽  
Author(s):  
Chih-Ming Ho ◽  
Ismet Gursul ◽  
Chiang Shih ◽  
Hank Lin ◽  
Mario Lee

2021 ◽  
Vol 9 ◽  
Author(s):  
Chenyi Su ◽  
Xingqi Xu ◽  
Jinghua Huang ◽  
Bailiang Pan

Abstract Considering the thermodynamical fluid mechanics in the gain medium and laser kinetic processes, a three-dimensional theoretical model of an exciplex-pumped Cs vapor laser with longitudinal and transverse gas flow is established. The slope efficiency of laser calculated by the model shows good agreement with the experimental data. The comprehensive three-dimensional distribution of temperature and particle density of Cs is depicted. The influence of pump intensity, wall temperature, and fluid velocity on the laser output performance is also simulated and analyzed in detail, suggesting that a higher wall temperature can guarantee a higher output laser power while causing a more significant heat accumulation in the cell. Compared with longitudinal gas flow, the transverse flow can improve the output laser power by effectively removing the generated heat accumulation and alleviating the temperature gradient in the cell.


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