The Effects of Reynolds Number on the Stall and Pre-Stall Behaviour of Compact Axial Compressors

2021 ◽  
Author(s):  
Jack Hutchings ◽  
Cesare Hall
Keyword(s):  
Reynolds Number ◽  
Axial Compressors

The Effect of Reynolds Number on Transonic Compressor Blade Rotor Section

2012 ◽  
Author(s):  
A. Shahrabi Farahani ◽  
H. Beheshti Amiri ◽  
H. Khazaei ◽  
A. Madadi ◽  
A. Fathi
Keyword(s):  
Reynolds Number ◽  
Stokes Equations ◽  
Pressure Ratio ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Blade Passage ◽  
Axial Compressors ◽  
Choked Flow ◽  
Transonic Compressor ◽  
Boundary Layer Interaction

To achieve at a more precise designing procedure in axial-compressors as well as a higher pressure ratio value, a comprehensive understanding on the flow aerodynamics and the governing phenomena is required. Existence of these complicated phenomena e.g., simultaneous production of supersonic and subsonic flows, shock-boundary layer interaction, unique incidence phenomenon, etc, makes it difficult to analyze the flow in the transonic compressors. One of the methods which is useful in the modeling of the phenomena occur in the compressors is investigating the flow in the blade to blade passage. In this paper, employing the simultaneous solution of the full Navier-Stokes equations (using the Roe-FDS numerical method) and turbulence equations (using the K–w (SST) model) the flow has been simulated in the blade to blade passage of a transonic compressor. In the following, in order to comparison the predicted results with experimental data, required adjustments and conditions have been taken into account. After passing through the first transonic compressor stages, the flow becomes remarkably compressed. In such conditions, the Reynolds number considerably changes compared to the inflow Reynolds number. In the present work, it is intended to numerically investigate the effects of the inflow Reynolds number on the unique incidence, flow losses, deviation angle, and also shock position changes, in three different important states of “Minimum loss” and “Choked flow” in started conditions and “Stall operation” in unstarted conditions.

Reynolds Number Effects in Axial Compressors

1968 ◽  
Vol 90 (2) ◽  
pp. 149-156 ◽  
Author(s):  
A. B. Wassell
Keyword(s):  
Reynolds Number ◽  
Total Pressure ◽  
Performance Parameters ◽  
Axial Compressors ◽  
Flow Reynolds Number ◽  
Reynolds Number Effects ◽  
Compressor Performance ◽  
Flow Changes ◽  
Design Speed ◽  
Main Compressor

The influence of variations in flow Reynolds number on the performance of axial compressors has been studied (changes in Reynolds number being, for the most part, achieved by changes in the inlet total pressure at or near the design speed). The measured results, so achieved, have been correlated to show how the main compressor performance parameters vary with Reynolds number. Reference has been made to cascade data to assist in choosing the form of the correlation, which is essentially empirical. A good correlation of the measured performance changes on component tests has been obtained. The method described, therefore, appears to be satisfactory for predicting trends for project assessments and avoids considering the detailed flow changes that occur within the machine as the Reynolds number is varied.

scholarly journals The Surge Problem as Related to the ASME Compressor Test Code PTC 10-1949

1960 ◽  
Author(s):  
Joseph T. Hamrick
Keyword(s):  
Reynolds Number ◽  
Common Ground ◽  
Axial Flow ◽  
Rotating Stall ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Axial Compressors ◽  
The Past ◽  
Rotating Blade ◽  
Aerodynamic Instability

Over the past decade a large amount of information has been accumulated on both centrifugal and axial compressors as a result of extensive research and development for gas turbine engines for aircraft. With the accumulation of this information it is important that a review be made of the ASME Power Test Code 10 for Centrifugal, Mixed-Flow and Axial Flow Compressors and Exhausters. As a result a committee has been appointed to revise ASME PTC 10 and bring it up to date. It is desirable as a part of this revised test code to include information on the problem of surging in compressors. Surging normally is defined as backflow which expresses itself both audibly and in violent instrument fluctuation. It is probable that the term surge should be extended to include any destructive forces that result from aerodynamic instability within the machine. If this is done, the problem of detection becomes more acute. For example, instabilities in both axial flow and centrifugal compressors which were not audible have resulted in failures. Rotating stall which has been reported in a number of papers has been investigated in both rotating blade rows and in stationary cascades. It is not the purpose of this paper to rehash the problem of rotating stall. Rather, it is intended here to discuss what aspects of aerodynamic instability should be considered by the user and the manufacturer and what common ground in compressor specifications can be met. It is recognized that although the compressor is normally the source of aerodynamic instabilities, these can be magnified by system arrangement. Therefore a compressor that operates quite satisfactorily in one system may fail in another. One of the main problems that is encountered in aerodynamic instability occurs with shifts in Reynolds number. Frequently the effects of Reynolds number change can be detected by running complete compressor maps over a range of inlet pressures. This in itself may require more testing than generally is expected by the supplier or the user. Therefore it is a second purpose of this discussion to emphasize the importance of thorough compressor test programs.

scholarly journals Boundary Layer Development in Axial Compressors and Turbines: Part 3 of 4 — LP Turbines

1995 ◽  
Author(s):  
David E. Halstead ◽  
David C. Wisler ◽  
Theodore H. Okiishi ◽  
Gregory J. Walker ◽  
Howard P. Hodson ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Experimental Evidence ◽  
Operating Condition ◽  
Axial Compressors ◽  
Boundary Layer Development ◽  
Computational Analyses ◽  
Hot Film ◽  
Layer Development ◽  
Detailed Picture

This is Part Three of a four-part paper. It begins with Section 11.0 and continues to describe the comprehensive experiments and computational analyses that have led to a detailed picture of boundary layer development on airfoil surfaces in multistage turbomachinery. In this part, we present the experimental evidence that we used to construct the composite picture for LP turbines that was given in the discussion in Section 5.0 of Part 1. We present and interpret the data from the surface hot-film gauges and the boundary layer surveys for the baseline operating condition. We then show how this picture changes with variations in Reynolds number, airfoil loading and nozzle-nozzle clocking.

Boundary Layer Development in Axial Compressors and Turbines: Part 3 of 4— LP Turbines

1997 ◽  
Vol 119 (2) ◽  
pp. 225-237 ◽  
Author(s):  
D. E. Halstead ◽  
D. C. Wisler ◽  
T. H. Okiishi ◽  
G. J. Walker ◽  
H. P. Hodson ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Experimental Evidence ◽  
Operating Condition ◽  
Axial Compressors ◽  
Boundary Layer Development ◽  
Computational Analyses ◽  
Hot Film ◽  
Layer Development ◽  
Detailed Picture

This is Part Three of a four-part paper. It begins with Section 11.0 and continues to describe the comprehensive experiments and computational analyses that have led to a detailed picture of boundary layer development on airfoil surfaces in multistage turbomachinery. In this part, we present the experimental evidence that we used to construct the composite picture for LP turbines that was given in the discussion in Section 5.0 of Part 1. We present and interpret the data from the surface hot-film gages and the boundary layer surveys for the baseline operating condition. We then show how this picture changes with variations in Reynolds number, airfoil loading, and nozzle–nozzle clocking.

Low Reynolds number flow around and heat transfer from a heated circular cylinder

2010 ◽  
Vol 1 (1-2) ◽  
pp. 15-20 ◽  
Author(s):  
B. Bolló
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Lift Coefficient ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Reynolds Number Flow ◽  
Two Dimensional Flow ◽  
Number Flow ◽  
Low Reynolds ◽  
Increasing Temperature

Abstract The two-dimensional flow around a stationary heated circular cylinder at low Reynolds numbers of 50 < Re < 210 is investigated numerically using the FLUENT commercial software package. The dimensionless vortex shedding frequency (St) reduces with increasing temperature at a given Reynolds number. The effective temperature concept was used and St-Re data were successfully transformed to the St-Reeff curve. Comparisons include root-mean-square values of the lift coefficient and Nusselt number. The results agree well with available data in the literature.

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