Design and Test of an Aspirated Counter-Rotating Fan

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Jack L. Kerrebrock ◽  
Alan H. Epstein ◽  
Ali A. Merchant ◽  
Gerald R. Guenette ◽  
David Parker ◽  
...  
Keyword(s):  
Static Pressure ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Suction Surface ◽  
Viscous Boundary Layer ◽  
Blade Loading ◽  
Design Speed ◽  
Viscous Boundary ◽  
Shock Loss

The design and test of a two-stage, vaneless, aspirated counter-rotating fan is presented in this paper. The fan nominal design objectives were a pressure ratio of 3:1 and adiabatic efficiency of 87%. A pressure ratio of 2.9 at 89% efficiency was measured at the design speed. The configuration consists of a counter-swirl-producing inlet guide vane, followed by a high tip speed (1450ft∕s) nonaspirated rotor and a counter-rotating low speed (1150ft∕s) aspirated rotor. The lower tip speed and lower solidity of the second rotor result in a blade loading above conventional limits, but enable a balance between the shock loss and viscous boundary layer loss; the latter of which can be controlled by aspiration. The aspiration slot on the second rotor suction surface extends from the hub up to 80% span. The bleed flow is discharged inward through the blade hub. This fan was tested in a short duration blowdown facility. Particular attention was given to the design of the instrumentation to measure efficiency to 0.5% accuracy. High response static pressure measurements were taken between the rotors and downstream of the fan to determine the stall behavior. Pressure ratio, mass flow, and efficiency on speed lines from 90% to 102% of the design speed are presented and discussed along with comparison to computational fluid dynamics predictions and design intent. The results presented here complement those presented earlier for two aspirated fan stages with tip shrouds, extending the validated design space for aspirated compressors to include designs with conventional unshrouded rotors and with inward removal of the aspirated flow.

Design and Test of an Aspirated Counter-Rotating Fan

2006 ◽  
Author(s):  
Jack L. Kerrebrock ◽  
Alan H. Epstein ◽  
Ali A. Merchant ◽  
Gerald R. Guenette ◽  
David Parker ◽  
...  
Keyword(s):  
Guide Vane ◽  
Pressure Ratio ◽  
Tip Clearance ◽  
Inlet Guide Vane ◽  
Suction Surface ◽  
Viscous Boundary Layer ◽  
Blade Loading ◽  
Design Speed ◽  
Viscous Boundary ◽  
Shock Loss

The design and test of a two-stage, vaneless, aspirated counter-rotating fan is presented in this paper. The fan nominal design objectives were a pressure ratio of 3:1 and adiabatic efficiency of 87%. A pressure ratio of 2.9 at 89% efficiency was measured in the tests. The configuration consists of a counter-swirl-producing inlet guide vane, followed by a high tip speed (1450 feet/sec) non-aspirated rotor, and a counter-rotating low speed (1150 feet/sec) aspirated rotor. The lower tip speed and lower solidity of the second rotor results in a blade loading above conventional limits, but enables a balance between the shock loss and viscous boundary layer loss, the latter of which can be controlled by aspiration. The aspiration slot on the second rotor suction surface extends from the hub up to 80% span, with a conventional tip clearance, and the bleed flow is discharged at the hub. The fan was tested in a short duration blowdown facility. Particular attention was given to the design of the instrumentation to obtain efficiency measurements within 0.5 percentage points. High response static pressure measurements were taken between the rotors and downstream of the fan to determine the stall behavior. Pressure ratio, mass flow, and efficiency on speedlines from 90% to 102% of the design speed are presented and discussed along with comparison to CFD predictions and design intent. The results presented here complement those presented earlier for two aspirated fan stages with tip shrouds, extending the validated design space for aspirated compressors to include designs with conventional unshrouded rotors and with inward removal of the aspirated flow.

Natural Transition Phenomena on an Axial Compressor Blade

2000 ◽  
Author(s):  
J. D. Hughes ◽  
G. J. Walker
Keyword(s):  
Guide Vane ◽  
Axial Compressor ◽  
Inlet Guide Vane ◽  
Instability Wave ◽  
Blade Loading ◽  
Instability Waves ◽  
Transition Prediction ◽  
Tollmien Schlichting ◽  
Vane Clocking ◽  
Hot Film

Data from a surface hot-film array on the outlet stator of a 1.5 stage axial compressor are analyzed to look for direct evidence of natural transition phenomena. An algorithm is developed to identify instability waves within the Tollmien Schlichting (T-S) frequency range. The algorithm is combined with a turbulent intermittency detection routine to produce space∼time diagrams showing the probability of instability wave occurrence prior to regions of turbulent flow. The paper compares these plots for a range of blade loading, with free-stream conditions corresponding to the maximum and minimum inflow disturbance periodicity produced by inlet guide vane clocking. Extensive regions of amplifying instability waves are identified in nearly all cases. The implications for transition prediction in decelerating flow regions on axial turbomachine blades are discussed.

scholarly journals Flow Measurements Behind the Inlet Guide Vane of a Centrifugal Compressor

1998 ◽  
Author(s):  
I. Kassens ◽  
M. Rautenberg
Keyword(s):  
Centrifugal Compressor ◽  
Total Pressure ◽  
Guide Vane ◽  
Incidence Angle ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Flow Measurements ◽  
Flow Angle ◽  
Partial Load ◽  
Measurement Location

In a centrifugal compressor adjustable inlet guide vanes (IGV) in front of the impeller are used to regulate the pressure ratio and the mass flow. The stationary measurement of the velocity profile in front of the impeller with different angles of the IGV displays shock losses at the inlet edge of blade of the impeller. In the partial-load region (e.g. partial-load efficiency) the radial distribution of the flow influences considerably the performance of the impeller. The tested compressor consists of an adjustable IGV with straight vanes, a shrouded impeller and a vaneless, parallel diffuser. In the first measurement location, behind the IGV, total pressure, static pressure and flow angle were measured with a 5-hole cylinder probe. In the second measurement location, in front of the impeller, the measurement of the total pressure was carried out with a Kiel probe and the flow angle with a Cobra probe accordingly the static wall pressure was measured. Taking into consideration the fundamental thermodynamical equations it was possible to determine the velocity profiles because of the measured distributions of the flow angle in these two measurement locations. For different angles of the IGV and with various mass flows the distributions of the deflection defect behind the IGV are described. Starting with the measured distributions of the flow in front of the impeller the flow angles at the impeller inlet are calculated and the distributions of the incidence angle at the impeller inlet are figured out.

Design of the High Pressure Ratio Transonic 1-1/2 Stage Fan Demonstrator Hulda

2007 ◽  
Author(s):  
Hans Ma˚rtensson ◽  
Jo¨rgen Burman ◽  
Ulf Johansson
Keyword(s):  
Guide Vane ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Demonstration Program ◽  
Good Efficiency ◽  
High Pressure Ratio ◽  
Mechanical Constraints ◽  
Computational Analyses ◽  
Variable Inlet Guide Vane ◽  
First Time

As the first design in a demonstration program for future fighter engine fans a 400 mm 1-1/2 stage fan has been designed and built. A new method including mechanical constraints for designing the blades and gas path is used for the first time on a new design. The approach closely integrates CFD for performance and FE methods for the structure. By this, advanced computational analyses affect the design from the early stages. A design that is successful in achieving good efficiency based on CFD as well as reasonable aeromechanical properties based on FE is derived. The fan incorporates a front frame (FF), variable inlet guide vane (VIGV), rotor 1 (R1) and stator 1 (S1).

Variable Inlet Guide Vane Effect on Centrifugal Compressor Performance in Wet Gas Flow

2016 ◽  
Author(s):  
Levi André B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Guide Vanes ◽  
Wet Gas ◽  
Compressor Performance

The introduction of variable inlet guide vanes (VIGVs) upfront of a compressor stage affects performance and permits tuning for off-design conditions. This is of great interest for emerging technology related to subsea compression. Unprocessed gas from the wellhead will contain liquid condensate, which affects the operational condition of the compressor. To investigate the effect of guide vanes on volume flow and pressure ratio in a wet gas compressor, VIGVs are implemented upfront of a centrifugal compressor stage to control the inlet flow direction. The guide vane geometry and test rig setup have previous been presented. This paper documents how changing the VIGV setting affects compressor performance under dry and wet operating conditions. The reduced performance effect and operating range at increased liquid content are of specific interest. Also documented is the change in the VIGV effect relative to the setting angle.

scholarly journals Secondary Flow Reduction in a Nozzle Guide Vane Cascade by Non-Axisymmetric End-Wall Profiling

1999 ◽  
Author(s):  
J. Yan ◽  
D. G. Gregory-Smith ◽  
P. J. Walker
Keyword(s):  
Secondary Flow ◽  
Static Pressure ◽  
Guide Vane ◽  
Suction Surface ◽  
Linear Cascade ◽  
Pressure Surface ◽  
Nozzle Guide Vane ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
End Wall

A linear cascade of HP steam turbine nozzle guide vanes was designed and built in order to study the effect of a non-axisymmetric profile for the endwall. The profile was designed by using CFD for the purpose of reducing the secondary flow. The method was to use convex curvature near the pressure surface to reduce the static pressure and concave curvature near the suction surface to increase it. Thus the cross passage pressure gradient which drives the secondary flow would be reduced. Detailed investigations of the flow field with a flat end-wall and the profiled end-wall were conducted. The effect of the profiled end-wall on the secondary flow development was determined and also compared with the CFD design predictions. It was found that the secondary loss and secondary kinetic energy were both reduced by about 20% with the shaped endwall, and a more uniform exit flow was also achieved.

Numerical simulation of circulation control turbine cascade with Coanda jet and counter-flow blowing at high Mach numbers

2017 ◽  
Vol 121 (1243) ◽  
pp. 1239-1260 ◽  
Author(s):  
Y. Feng ◽  
Y. Song ◽  
F. Chen
Keyword(s):  
Guide Vane ◽  
Inlet Guide Vane ◽  
Circulation Control ◽  
Turbine Cascade ◽  
Flow Conditions ◽  
Suction Surface ◽  
Counter Flow ◽  
Flow Angle ◽  
High Mach ◽  
Coanda Jet

ABSTRACTThe performance of a circulation-control inlet guide vane that makes use of the Coanda effect was studied numerically in a high Mach number turbine cascade. The effect of different shapes (elliptic and circular) of the Coanda surface at the blade trailing edge was investigated by implementing both a Coanda jet and a counter-flow blowing. Under high subsonic flow conditions, with a total blowing ratio of 3% of the mainstream, the circulation control cascade can reach the same performance as the reference stator with a 13.5% reduction in the axial chord length, with minimal increase of the energy loss coefficient. The Coanda surfaces with small curvature are more efficient in entraining the mainstream flow, and they achieve better aerodynamic performance. The wall attachment of the Coanda jet is improved by employing counter-flow blowing, resulting in a slight increase of both the exit flow angle and the expansion ratio. Under supersonic flow conditions at the cascade exit, it is more difficult for the circulation control cascade to reach the appropriate flow turning due to a premature shock wave, which is absent in the original cascade until the very end of the suction surface.

Online Performance Monitoring of Industrial Compressors Using Meanline Modelling

2014 ◽  
Author(s):  
Matteo Cicciotti ◽  
Dionysios P. Xenos ◽  
Ala E. F. Bouaswaig ◽  
Nina F. Thornhill ◽  
Ricardo F. Martinez-Botas
Keyword(s):  
Performance Monitoring ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Mechanical Degradation ◽  
Adaptive Parameters ◽  
Online Performance Monitoring ◽  
Constrained Minimization Problem ◽  
Inlet Conditions ◽  
Process Measurements

This paper proposes a framework for detecting mechanical degradation online and assessing its effect on the performance of industrial compressors. It consists of a model of the machine in undegraded condition and of a degradation adaptive model. The proposed methodology for online degradation detection differentiates itself from those found in the literature as the undegraded model is not linearized and ambient/inlet conditions are explicitly taken into account. The degradation is modelled through adaptive parameters which are estimated and updated online through the solution of a constrained minimization problem within a moving window. It uses available process measurements of flow, pressures, temperatures and composition. The update of the parameters guarantees the model accuracy and it permits the estimation of the effects of mechanical degradation away from the compressor running line. The performance monitoring framework has been successfully applied on an industrial air centrifugal compressor. It was found that after 3250 hours of operation from the previous maintenance the efficiency and the pressure ratio had dropped approximately 5.5% and 2.5% of their respective undegraded values. Furthermore, it was found that the performance deviations from the baseline depend from the position of the operative point in the performance map. In fact, the pressure ratio drop was lower (2%) and efficiency drop was higher (6%) for lower inlet guide vanes opening whereas pressure ratio drop was higher (3%) and efficiency drop was lower (1.6%) for higher inlet guide vane opening.

Effects of Axial Row-Spacing for Double-Jet Film-Cooling on the Cooling Effectiveness

2011 ◽  
Author(s):  
Zhan Wang ◽  
Jian-Jun Liu ◽  
Bai-tao An ◽  
Chao Zhang
Keyword(s):  
Film Cooling ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Row Spacing ◽  
Suction Surface ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Pressure Surface ◽  
Cylindrical Holes ◽  
Compound Angle

The effects of axial row-spacing for double jet film-cooling (DJFC) with compound angle on the cooling characteristics under different blowing ratios were investigated numerically. First, the flow fields and cooling effectiveness of DJFC on flat plate with different axial row-spacing were calculated. Film-cooling with fan-shaped or cylindrical holes was also calculated for the comparison. The results indicate that a larger axial row-spacing is helpful to form the anti-kidney vortex and to improve the cooling effectiveness. The DJFC was then applied to the suction and pressure surface of a real turbine inlet guide vane. Comparisons of film-cooling effectiveness with the cylindrical and fan-shaped holes were also conducted. The results for the guide vane show that on the suction surface the DJFC with a larger axial row-spacing leads to better film coverage and better film-cooling effectiveness than the cylindrical or fan-shaped holes. On the pressure surface, however, the film-cooling with fan-shaped holes is superior to the others.

Numerical Study of Variable Camber Inlet Guide Vane on Low Speed Axial Compressor

2015 ◽  
Author(s):  
Emandi Rajesh ◽  
Bhaskar Roy
Keyword(s):  
High Efficiency ◽  
Numerical Study ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Operating Range ◽  
Clockwise Direction ◽  
High Diffusion ◽  
Stable Operating ◽  
Stagger Angle

The modern engine has the requirement of high pressure ratio compressors. High diffusion blades are used to cater to this requirement. The high diffusion blades suffer from the low incidence range. A variable geometry inlet guide vane is used to improve the incidence range and to have an increased stable operating range. In this paper a variable camber inlet guide is proposed in place of an existing inlet guide vane (IGV) to operate the compressor at increased stable operating range or to operate at improved efficiency at off design point. Numerical analysis is carried out in ANSYS CFX©. The existing compressor consists of IGV (20 blades) , rotor (43 blades) and stator (52 blades). The rotor rotates at 2400 rpm in clockwise direction. The IGV blade is split two part forward blade and aft blade. Numerical studies are conducted to study the effect of varying the stagger angle on the performance of the compressor. The aft blade is given rotation in clockwise direction for +5° and +10°. The numerical results obtained are compared to the same stagger angle with full blades. It is observed that marginal improvement in the pressure ratio and efficiency. 7% stall margin improvement is achieved with slotted blade in place a fixed IGV at 0° setting angle. A new compressor characteristics is estimated which shows that the compressor can be operated to the left of the fixed-IGV-stage peak pressure with high efficiency.

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