The Mechanisms of Noise Generation in a Compressor Model

1967 ◽  
Vol 89 (2) ◽  
pp. 191-197 ◽  
Author(s):  
B. T. Hulse ◽  
J. B. Large
Keyword(s):  
Vortex Shedding ◽  
Mathematical Analysis ◽  
Axial Flow ◽  
Noise Generation ◽  
Compressor Blades ◽  
Rotor Noise ◽  
Blade Thickness ◽  
Flow Compressor ◽  
Analytical Expressions ◽  
Good Agreement

A study is being undertaken in order to gain a better understanding of how compressor noise is produced. To facilitate mathematical analysis, the noise-generating mechanisms of axial-flow compressor blades have been investigated using flat blades. Analytical expressions are given for calculating the compressor noise due to blade thickness, loading, and vortex shedding. Measured values of compressor noise show good agreement with analytical predictions. It has been found that the lift, or loading noise, dominates the blade thickness noise. Rotor-stator spacing is an important parameter in rotor noise generation.

Aeroelastic Stability Analysis of Supersonic Cascades

1979 ◽  
Vol 101 (4) ◽  
pp. 533-541 ◽  
Author(s):  
J. A. Strada ◽  
W. R. Chadwick ◽  
M. F. Platzer
Keyword(s):  
Flat Plate ◽  
Leading Edge ◽  
Experimental Information ◽  
Nonlinear Method ◽  
Three Solutions ◽  
Blade Loading ◽  
Pressure Distributions ◽  
Blade Thickness ◽  
Analytical Expressions ◽  
Good Agreement

This paper presents three solutions for the analysis of supersonic flow past oscillating cascades with subsonic leading-edge locus. A quite elementary solution is first developed for the case of slowly oscillating finite and infinite flat plate cascades which provides simple analytical expressions for the unsteady pressure distributions. Comparisons with other solutions show generally excellent agreement. Furthermore, a previously developed linearized characteristics solution for finite flat plate cascades is applied to the case of superresonant blade motions. Again, the unsteady blade loading distributions are found to be in good agreement with Verdon’s recent infinite cascade solution for this case. Finally, a nonlinear method of characteristics solution for finite cascades is described which permits the analysis of blade thickness effects on flutter. At this time, only the inlet and passage flow computations have been completed which are compared with the available experimental information.

Computation of Potential Flow on S2 Stream Surface for a Transonic Axial-Flow Compressor Rotor

1985 ◽  
Vol 107 (2) ◽  
pp. 323-328 ◽  
Author(s):  
Pan-Ming Lu¨ ◽  
Chung-Hua Wu
Keyword(s):  
Potential Function ◽  
Axial Compressor ◽  
Axial Flow ◽  
Full Potential ◽  
Stream Surface ◽  
Compressor Rotor ◽  
Transonic Axial Compressor ◽  
Design Speed ◽  
Flow Compressor ◽  
Good Agreement

A set of conservative full potential function equations governing the fluid flow along a given S2 streamsurface in a transonic axial compressor rotor was obtained. By the use of artificial density and a potential function/density iteration, this set of equations can be solved, and the passage shock on the S2 streamsurface can be captured. A computer program for this analysis problem has been developed and used to compute the flow field along a mean S2 streamsurface in the DFVLR transonic axial compressor rotor. A comparison of computed results with DFVLR L2F measurement at 100 percent design speed shows fairly good agreement.

Untwist of Rotating Blades

1975 ◽  
Vol 97 (2) ◽  
pp. 180-187 ◽  
Author(s):  
M. Ohtsuka
Keyword(s):  
Cross Section ◽  
Virtual Work ◽  
Axial Flow ◽  
Arbitrary Cross Section ◽  
Principle Of Virtual Work ◽  
Centrifugal Forces ◽  
Governing Equations ◽  
Compressor Rotor ◽  
Flow Compressor ◽  
Good Agreement

This paper deals with the deformation and the stress of an axial flow compressor rotor blade under the loading of centrifugal forces. Coupled deformation of extension, bending, torsion and transverse shear of a pretwisted curved bar with arbitrary cross section is considered. Governing equations derived by means of the principle of virtual work are solved numerically by finite difference method. The warping functions used in the analysis were obtained by the use of finite element method. Measurement of the untwist angles and the stresses were carried out for the verification of the numerical analysis and they were found to be in good agreement.

Numerical Investigation of Tandem Airfoils for Subsonic Axial-Flow Compressor Blades

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Jonathan McGlumphy ◽  
Wing-Fai Ng ◽  
Steven R. Wellborn ◽  
Severin Kempf
Keyword(s):  
Axial Flow ◽  
Computational Approach ◽  
Compressor Blade ◽  
Large Scatter ◽  
Compressor Blades ◽  
Cascade Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Overall Performance ◽  
Flow Compressor

The tandem airfoil has potential to do more work as a compressor blade than a single airfoil without incurring significantly higher losses. Although tandem blades are sometimes employed as stators, they have not been used in any known commercial rotors. While the long-term goal for this program is development of a commercially viable tandem rotor, this paper discusses tandem airfoils in subsonic, shock-free rectilinear cascade flow. Existing literature data on tandem airfoils in rectilinear cascades have been compiled and presented in a Lieblein loss versus loading correlation. Large scatter in the data gave motivation to conduct an extensive 2D computational fluid dynamics (CFD) study evaluating the overall performance as a function of the relative positions of the forward and aft airfoils. CFD results were consistent with trends in the open literature, both of which indicate that a properly designed tandem airfoil can outperform a comparable single airfoil on and off design. The general agreement of the CFD and literature data serves as a validation for the computational approach.

Sign in / Sign up

Export Citation Format

Share Document