Transonic Compressor Rotor Design Using Non-Monotonic Meanline Angle Distribution

2007 ◽  
Author(s):  
Zongjun Hu ◽  
Gecheng Zha ◽  
Matthew Montgomery ◽  
Thomas Roecken ◽  
John Orosa
Keyword(s):  
Mach Number ◽  
Rotor Blade ◽  
Angle Distribution ◽  
Stall Margin ◽  
Blade Passage ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Rotor Design ◽  
Blade Section ◽  
Transonic Rotor

A non-monotonic meanline angle distribution technique with local negative camber is applied to a transonic rotor blade from the hub area to tip with the inlet Mach number varying from subsonic to low supersonic. The blade passage area is controlled by the non-monotonic meanline angle distribution, which results in reduced peak Mach number and weakened or removed shock wave. The negative camber is used downstream of the throat and hence it does not affect the flow passing capability of the blade section. The design point efficiency is significantly increased and the stall margin at part speed is also improved. Detailed results are given in the paper.

Experimental and numerical investigation of a subsonic compressor with bend-skewed slot-casing treatment

2006 ◽  
Vol 220 (12) ◽  
pp. 1785-1796 ◽  
Author(s):  
X Lu ◽  
W Chu ◽  
Y Zhang ◽  
J Zhu
Keyword(s):  
Rotor Blade ◽  
Axial Flow ◽  
Efficiency Gain ◽  
Stall Margin ◽  
Blade Passage ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor ◽  
Isentropic Efficiency

On the basis of the test results of discrete axial and blade angle slot casing treatment, a new type of casing treatment was designed for a subsonic axial flow compressor rotor by optimizing various geometry parameters. To obtain a wide operating range and to minimize penalties in terms of isentropic efficiency, seven compressor configurations incorporating casing treatments of 0, 16.6, 33.3, 50, 66.6, 83.3, and 100 per cent rotor exposures were experimentally investigated. The results showed that significant improvements in stall margin are possible in all exposures and insignificant isentropic efficiency sacrifices are recorded in some exposures. Nearly 21.43 per cent stall margin improvement in terms of the corrected mass flow-rate was achieved with 33.3 per cent rotor blade tip axial chord exposure. The compressor built with 16.6 per cent rotor exposure was the best configuration in terms of maximum isentropic efficiency gain. The second issue of the paper was to offer a contribution to the understanding of the physical mechanism by which bend-skewed slot-casing treatment improves stall margin under subsonic conditions. By applying a concept similar to ‘Domain scaling’ approach (as often used in multistage turbomachinery flow-fields) to the interface between the rotor blade passage and end-wall treatments, a time-dependent three-dimensional numerical simulation was performed for the subsonic axial-flow compressor rotor with bend-skewed slot-casing treatment. The numerical results agreed well with the available experimental results. Detailed analyses of the coupled flow through bend-skewed slot-casing treatment and rotor blade passage under subsonic conditions led to some preliminary conclusions as to the flow physics involved in the stall margin improvements afforded by the use of bend-skewed slot-casing treatment.

The Effect of Steam Ingestion on Transonic Rotor Stall Margin

2007 ◽  
Author(s):  
A. J. Gannon ◽  
G. V. Hobson ◽  
T. A. Payne ◽  
S. E. Zarro
Keyword(s):  
High Speed ◽  
Initial Conditions ◽  
Flow Conditions ◽  
Stall Margin ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
High Speed Data ◽  
Inlet Conditions ◽  
Transonic Rotor ◽  
Temperature Water

The adverse effect of high temperature water vapor on the stall margin of a transonic compressor rotor is investigated. This type of flow condition is experienced during the takeoff of carrier born aircraft. An experiment is designed to replicate these flow conditions on a transonic compressor test rig. The transient inlet conditions are measured and the changes in gas properties as well as the reduction in stall margin for differing steam inlet pressures are presented. High speed data measurements are used to investigate the initial conditions of the compressor before steam is introduced to the flow. Evidence of pre-cursors rotating at near half rotor speed are found and the strength of these appear to give an indication of the compressor’s susceptibility to stall.

Experimental Cascade Analysis of a Transonic Compressor Rotor Blade Section

1984 ◽  
Vol 106 (2) ◽  
pp. 288-294 ◽  
Author(s):  
H. A. Schreiber ◽  
H. Starken
Keyword(s):  
Rotor Blade ◽  
Flow Behavior ◽  
Density Ratio ◽  
Axial Flow ◽  
Flow Angle ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Blade Row ◽  
Blade Section ◽  
Transonic Cascade

A transonic compressor rotor blade cascade was tested in order to elucidate the flow behavior in the transonic regime and to determine the performance characteristic in the whole operating range of a rotor blade section. The experiments have been conducted in a transonic cascade wind tunnel, which enables tests even at sonic inlet velocities. The influence of the upstream Mach number between 0.8 and 1.1 and the inlet flow angle between choking and stalling of the blade row was investigated. The effect of the axial velocity density ratio (AVDR) could be studied by applying an endwall suction device. Furthermore, the level of the shock losses was determined from a wake analysis. A final comparison of cascade losses and those of the corresponding rotor blade element shows good agreement which underlines the applicability of the cascade model in the design of axial flow turbomachines.

Experimental and Numerical Investigation of a Subsonic Compressor With Bend Skewed Slot Casing Treatment

2006 ◽  
Author(s):  
Xingen Lu ◽  
Wuli Chu ◽  
Junqiang Zhu ◽  
Yanhui Wu
Keyword(s):  
Rotor Blade ◽  
Axial Flow ◽  
Efficiency Gain ◽  
Stall Margin ◽  
Blade Passage ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Flow Compressor ◽  
Isentropic Efficiency

Based on the test results of discrete axial and blade angle slot casing treatment, a new type of casing treatment was designed for a subsonic axial flow compressor rotor by optimising various geometry parameters. To obtain a wide operating range and to minimize penalties in terms of isentropic efficiency, seven compressor configurations incorporating casing treatments of 0%, 16.6%, 33.3%, 50%, 66.6%, 83.3% and 100% rotor exposure were experimentally investigated. The results showed that significant improvements in stall margin are possible in all exposures and insignificant isentropic efficiency sacrifices are recorded in some exposures. Nearly 21.43% stall margin improvement in terms of the corrected mass flow rate was achieved with 33.3% rotor blade tip axial chord exposure. The compressor build with 16.6% rotor exposure was the best configuration in terms of maximum isentropic efficiency gain. The second issue of the paper was to offer a contribution to the understanding of the physical mechanism by which bend skewed slot casing treatment improve stall margin under subsonic conditions. By applying a concept similar to “Domain Scaling” approach (as often used in multistage turbomachinery Flow-fields) to the interface between the rotor blade passage and end-wall treatments, a time-dependent 3-dimentional numerical simulation was performed for the subsonic axial-flow compressor rotor with bend skewed slot casing treatment. The numerical results agreed well with experimental results. Detailed analyses of the coupled flow through bend skewed slot casing treatment and rotor blade passage under subsonic conditions led to some preliminary conclusions as to the flow physics involved in the stall margin improvements afforded by the use of bend skewed slot casing treatment.

Experimental Cascade Analysis of a Transonic Compressor Rotor Blade Section

1983 ◽  
Author(s):  
H. A. Schreiber ◽  
H. Starken
Keyword(s):  
Rotor Blade ◽  
Density Ratio ◽  
Axial Flow ◽  
Flow Angle ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Blade Row ◽  
Blade Section ◽  
Transonic Cascade ◽  
Good Agreement

A transonic compressor rotor blade cascade was tested in order to elucidate the flow behaviour in the transonic regime and to determine the performance characteristic in the whole operating range of a rotor blade section. The experiments have been conducted in a transonic cascade wind tunnel, which enables tests even at sonic inlet velocities. The influence of the upstream Mach number between 0.8 and 1.1 and the inlet flow angle between choking and stalling of the blade row was investigated. The effect of the axial velocity density ratio (AVDR) could be studied by applying an endwall suction device. Furthermore the level of the shock losses was determined from a wake analysis. A final comparison of cascade losses and those of the corresponding rotor blade element shows good agreement which underlines the applicability of the cascade model in the design of axial flow turbomachines.

Transonic Compressor Rotor Cascade With Boundary-Layer Separation: Experimental and Theoretical Results

1993 ◽  
Author(s):  
R. Fuchs ◽  
W. Steinert ◽  
H. Starken
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
Computational Design ◽  
Boundary Layer Separation ◽  
Ratio Test ◽  
Integral Boundary ◽  
Flow Angle ◽  
Laminar Separation ◽  
Transonic Compressor ◽  
Compressor Rotor

A transonic compressor rotor cascade designed for an inlet Mach number of 1.09 and 14 degrees of flow turning has been redesigned for higher loading by an increased pitch-to-chord ratio. Test results, showing the influence of inlet Mach number and flow angle on cascade performance are presented and compared to data of the basic design. Loss-levels of both, the original and the redesigned higher loaded blade were identical at design condition, but the new design achieved even lower losses at lower inlet Mach numbers. The computational design and analysis has been performed by a fast inviscid time-dependent code coupled to a viscous direct/inverse integral boundary-layer code. Good agreement was achieved between measured and predicted surface Mach number distributions as well as exit-flow angles. A boundary-layer visualization method has been used to detect laminar separation bubbles and turbulent separation regions. Quantitative results of measured bubble positions are presented and compared to calculated results.

Numerical Investigation of Casing Treatment Mechanisms With a Conservative Mixed-Cell Approach

2003 ◽  
Author(s):  
H. Yang ◽  
D. Nuernberger ◽  
E. Nicke ◽  
A. Weber
Keyword(s):  
Operating Conditions ◽  
Coupled Flow ◽  
Mixed Cell ◽  
Stall Margin ◽  
Casing Treatment ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Grid Topology ◽  
The Face ◽  
Overall Efficiency

A conservative mixed-cell approach of second-order accuracy is presented and applied to investigate the mechanisms of a self-recirculating casing treatment coupled with a transonic compressor rotor. The mixed cell is a computational cell that may show up at the zonal interface boundary, the face of which is partially solid and partially fluid, if the azimuthal open area of casing treatment does not fully contact with the whole annulus of blade passage. The mixed-cell approach is essentially an extension of the conservative zonal approach by incorporating special mixed-cell handling at the zonal interface and it allows a great flexibility to the grid generation for the patched zones with the best grid topology. The mixed-cell approach is extremely useful for solving the unsteady interaction problems within turbomachinery and its application for simulating the coupled flow through the rotor and the casing treatment is reported. The calculated results and analysis reveal an effective stall margin extension of the casing treatment herein by weakening or even destroying the tip leakage vortex, and expose the different tip flow topologies between the cases with the casing treatment and with the untreated smooth wall. It is found that the casing treatment only slightly decreases the overall efficiency at the design point, but it is beneficial to the overall efficiency at the off-design operating conditions and it can improve the inflow conditions to the downstream stator blade row as well.

scholarly journals Navier-Stokes Solutions of Unsteady Flow in a Compressor Rotor

1986 ◽  
Author(s):  
James N. Scott ◽  
Wilbur L. Hankey
Keyword(s):  
Unsteady Flow ◽  
Turbulence Model ◽  
Stokes Equations ◽  
Numerical Procedure ◽  
Navier Stokes ◽  
Suction Surface ◽  
Blade Passage ◽  
Radial Location ◽  
Transonic Compressor ◽  
Compressor Rotor

In order to achieve more accurate predictions of unsteady flow in a transonic compressor rotor an existing numerical approach has been modified by incorporating a turbulence model. The computations are performed by solving the complete time-dependent compressible Navier-Stokes equations using MacCormack’s explicit finite difference algorithm. These equations are solved for the flow through two adjacent rotor blades at a stream surface near the blade tip subjected to the wakes emitted from upstream stators. At this radial location the flow enters the blade passage at an absolute Mach number of 0.66. The high blade curvature at this radial location produces a large region of separated flow on the suction surface with laminar flow. To more accurately resolve the features of this flow separation the Baldwin-Lomax algebraic eddy-viscosity turbulence model is incorporated into the numerical procedure in regions, near the blade surface. The unsteady flow features are represented at the inflow boundary through the use of characteristic variables involving the upstream and downstream running Riemann invariants and the entropy variation expressed in terms of the total pressure profile. At the outflow boundary the concept of a “second throat” or choke point is implemented in conjunction with supersonic outflow conditions. The results are compared with numerical results obtained without the use of a turbulence model (laminar) for a single blade passage. Improved agreement with limited experimental data is also noted.

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