scholarly journals Experimental Noise Studies of Inlet Guide Vane‐Rotor‐Stator Interactions for a Single‐Stage Axial‐Flow Compressor

1965 ◽  
Vol 38 (5) ◽  
pp. 920-920
Author(s):  
J. L. Crigler ◽  
W. L. Copeland
Author(s):  
Theoklis Nikolaidis ◽  
Periclis Pilidis ◽  
J. A. Teixeira ◽  
V. Pachidis

A numerical approach was used to evaluate the liquid water film thickness and its motion on an axial flow compressor rotor blade under water ingestion conditions. By post-processing blading data and using computer programs to create the blades and their computational grid, the global computational domain of the first stage of an axial flow compressor was built. The flow field within the domain was solved by CFX-Tascflow, which is a commercial CFD code commonly used in turbomachinery. The computational domain consists of an extended inlet, an inlet guide vane, a rotor and a stator blade. Having solved the flow field at Design Point, the inlet guide vane blade was re-positioned to account for changes in idle speed. At that speed, the effects of water ingestion are expected to be more significant on gas turbine engine performance. Several cases with water ingestion were studied, changing parameters like water mass and compressor rotational speed. A FORTRAN computer program was created to calculate the water film height and speed. The extra torque needed by the compressor to keep running at the same rotational speed, was also calculated. The considerable increase in torque was confirmed by experimental observations according to which water ingestion had a detrimental effect on gas turbine operation.


Author(s):  
T. H. Okiishi ◽  
G. H. Junkhan ◽  
G. K. Serovy

Aerodynamic performance of a variable-geometry axial-flow compressor inlet guide vane configuration for a gas turbine unit was determined in a series of annular cascade tests. The variable-geometry vanes used uncambered, symmetrical airfoil sections as the basic blade profile with the rear 70 percent of the vane profile movable as a trailing-edge flap. Vane flap mechanical setting angles of 0 to 50 deg measured from the axial direction were possible, and performance parameters were determined over this range of angles. Turning angles followed a general trend obtained with Carter’s rule for accelerating cascades with the presently measured values tending to be lower than those obtained with Carter’s rule at higher setting angles. For large camber angles (greater than 35 deg) zero-incidence blade element total-pressure loss coefficients for the 50 percent passage location of the flapped vanes tested were higher than those that might have been obtained with a continously cambered vane row of the same solidity and camber.


Author(s):  
Anand P. Darji ◽  
Dilipkumar Bhanudasji Alone ◽  
Chetan S. Mistry

A transonic axial flow compressor undergoes severe vibrations due to instabilities like stall and surge when it operates at lower mass flow rate in the absence of any control devices. In present study, the attempt was made to understand the combine impact of circumferential casing grooves (CCG) of constant aspect ratio and different axial spacing between rotor and stator on the operating stability of single stage transonic axial compressor and that of rotor alone using numerical simulation. The optimum rotor-stator gap in the presence of grooved casing treatment was identified. The steady state numerical analysis was performed by using three-dimensional Reynolds Average Navier-Stokes equation adapting shear stress transport (SST) k-ω turbulence model. The study is reported in two sections. First section includes the detailed numerical study on baseline case having smooth casing wall (SCW). The computational results were validated with the experimental results available at Propulsion Division of CSIR-NAL, Bangalore. The computational study shows good agreement with experimental results. The second section comprises the effects of optimum designs of CCG and various axial spacing on the stall margin improvement of transonic compressor. Current computational study shows that the axial spacing between rotor and stator is an important parameter for improvement in stall margin not only for SCW but also for CCG. Therefore, the highest stall margin improvement of 9% has achieved for 75% axial spacing.


1984 ◽  
Vol 106 (2) ◽  
pp. 337-345
Author(s):  
B. Lakshminarayana ◽  
N. Sitaram

The annulus wall boundary layer inside the blade passage of the inlet guide vane (IGV) passage of a low-speed axial compressor stage was measured with a miniature five-hole probe. The three-dimensional velocity and pressure fields were measured at various axial and tangential locations. Limiting streamline angles and static pressures were also measured on the casing of the IGV passage. Strong secondary vorticity was developed. The data were analyzed and correlated with the existing velocity profile correlations. The end wall losses were also derived from these data.


1998 ◽  
Vol 4 (4) ◽  
pp. 217-231
Author(s):  
Heinz E. Gallus

Detailed results of unsteady flow measurements in a stator-rotor-stator assembly of an axial-flow turbine as well as an inlet guide vane-rotor-stator formation of an axial-flow compressor are presented in this paper.The measurements include the time-dependent 3-D velocity vector fields in the axial gaps between the blade rows by means of triple-hot wire-technique, furthermore the total pressure field downstream of the blade rows by means of semiconductor total pressure probes and the unsteady flow field determination in the rotor passages by LDV-technique. Special semiconductor pressure measurements along the casing all over the rotor tip clearance permit detailed discussion of the rotor tip clearance flows.The conclusion of the measured data provides a new and very instructive view of the physics of the unsteady blade-row interaction in axial-flow turbines and compressors.


Author(s):  
M. T. Shobhavathy ◽  
Premakara Hanoca

This paper comprises the Computational Fluid Dynamic (CFD) analysis to investigate the flow behaviour of a high speed single stage transonic axial flow compressor. Steady state analyses were carried out at design and part speed conditions to obtain the overall performance map using commercial CFD software ANSYS FLUENT. Radial distribution of flow parameters were obtained at 90% of design speed for the choked flow and near stall flow conditions. The predicted data were validated against available experimental results. The end wall flow fields were studied with the help of velocity vector plots and Mach number contours at peak efficiency and near stall flow conditions at 60% and 100% design speeds. This study exhibited the nature of a transonic compressor, having strong interaction between the rotor passage shock and the tip leakage vortex at design speed, which generates a region of high blockage in the rotor blade passage. The influence of this interaction extends around15% of the blade outer span at design speed and in the absence of blade passage shock at 60% design speed, the influence of tip leakage flow observed was around 8%.


Author(s):  
Kirubakaran Purushothaman ◽  
N. R. Naveen Kumar ◽  
Vidyadheesh Pandurangi ◽  
Ajay Pratap

Abstract Variability in stator vanes is a widely used technique to improve the stability and efficiency of axial flow compressor in gas turbine engines. Most of the modern aircraft jet engines use variable stator vanes in both low pressure and high pressure compressors primarily for off-design performance. This study discusses in detail about the effect of stator variability in a three stage low pressure axial compressor at design and off-design conditions. Computational flow analysis were carried out for the three stage low pressure compressor with variability in inlet guide vane and first stage stator blade. Detailed investigation on flow physics was carried out in rotor blade passages with stator variability. At off-design speeds, the reduction in flow velocity is lower than the reduction in blade tip speed. This leads to mismatch in flow angles and inlet blade angles causing high incidence and large flow separation in blade passage. This results in poor aerodynamic stability of the axial compressor at off-design speeds. In this study, aerodynamic performance of compressor is evaluated from 70% to 100% design speeds with different stagger angle setting of inlet guide vane at each speed. Further, to improve 2nd stage rotor performance, variability was introduced in 1st stage stator blade and performance was evaluated. Compressor test results are compared with CFD data for design and off-design speeds.


Author(s):  
Pritam Batabyal ◽  
Dilipkumar B. Alone ◽  
S. K. Maharana

This paper presents a numerical case study of various stepped tip clearances and their effect on the performance of a single stage transonic axial flow compressor, using commercially available software ANSYS FLUENT 14.0. A steady state, implicit, three dimensional, pressure based flow solver with SST k-Ω turbulence model has been selected for the numerical study. The stepped tip clearances have been compared with the baseline model of zero tip clearance at 70% and 100 % design speed. It has been observed that the compressor peak stage efficiency and maximum stage pressure ratio decreases as the tip clearances in the rear part are increased. The stall margin also increases with increase in tip clearance compared to the baseline model. An ‘optimum’ value of stepped tip clearance has been obtained giving peak stage compressor performance. The CFD results have been validated with the earlier published experimental data on the same compressor at 70% design speed.


1993 ◽  
Vol 115 (1) ◽  
pp. 197-206 ◽  
Author(s):  
S. R. Manwaring ◽  
S. Fleeter

A series of experiments is performed in an extensively instrumented axial flow research compressor to investigate the fundamental flow physics of wake-generated periodic rotor blade row unsteady aerodynamics at realistic values of the reduced frequency. Unique unsteady data are obtained that describe the fundamental unsteady aerodynamic gust interaction phenomena on the first-stage rotor blades of a research axial flow compressor generated by the wakes from the inlet guide vanes. In these experiments, the effects of steady blade aerodynamic loading and the aerodynamic forcing function, including both the transverse and chordwise gust components, and the amplitude of the gusts, are investigated and quantified.


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