The Effect of Inlet Guide Vanes on Inlet Flow Distortion Transfer and Transonic Fan Stability

2013 ◽  
Author(s):  
M. J. Shaw ◽  
P. Hield ◽  
P. G. Tucker
Keyword(s):  
Experimental Data ◽  
Stability Margin ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Computational Fluid Dynamics Cfd ◽  
Inlet Flow Distortion ◽  
Transonic Fan ◽  
Do So

An investigation has been carried out into the effects of variable inlet guide vanes (VIGVs) on the performance and stability margin of a transonic fan in the presence of inlet flow distortion. The study was carried out using computational fluid dynamics (CFD) and validated with experimental data. The capability of CFD to predict the changes in performance with or without VIGVs in the presence of an inlet flow distortion is assessed. Results show that the VIGVs improve the performance and stability margin and do so by reducing the amount of swirl at inlet to the rotor component of the fan.

The Effect of Inlet Guide Vanes on Inlet Flow Distortion Transfer and Transonic Fan Stability

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
M. J. Shaw ◽  
P. Hield ◽  
P. G. Tucker
Keyword(s):  
Experimental Data ◽  
Stability Margin ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Computational Fluid Dynamics Cfd ◽  
Inlet Flow Distortion ◽  
Transonic Fan ◽  
Do So

An investigation was carried out into the effects of variable inlet guide vanes (VIGVs) on the performance and stability margin of a transonic fan in the presence of inlet flow distortion. The study was carried out using computational fluid dynamics (CFD) and validated with experimental data. The capability of CFD to predict the changes in performance with or without VIGVs in the presence of an inlet flow distortion is assessed. Results show that the VIGVs improve the performance and stability margin and do so by reducing the amount of swirl at inlet to the rotor component of the fan.

The Effects of the Inlet Guide Vanes on an Axial Pump Under Off Design Points

2018 ◽  
Author(s):  
Zhi-Wei Guo ◽  
Jing-Ye Pan ◽  
Zhong-Dong Qian
Keyword(s):  
Experimental Data ◽  
Tip Clearance ◽  
Positive Slope ◽  
Guide Vanes ◽  
Stall Inception ◽  
Inlet Guide Vanes ◽  
Axial Pump ◽  
Axial Pumps ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

The performances of an axial pump with and without inlet guide vanes (IGVs) are investigated by both experimental method and computational fluid dynamics (CFD) method. Besides the stall inception, an obvious “positive slope” phenomenon appears under off-design operating points in experiment without IGVs. The experimental data also shows that IGVs can change the performance of axial pumps and remove the “positive slope”. The CFD is mainly used to reveal the mechanism of the “positive slope” phenomenon, where the simulated results are firstly validated in comparison with the experimental data. The results obtained show that the reason for this “positive slope” is due to the backflow vortex in front of the impeller, and the tip clearance is found to take an important role in forming this backflow vortex.

scholarly journals Investigation of Flows in Rectangular Diffusers With Inlet Flow Distortion

1982 ◽  
Author(s):  
M. M. Al-Mudhafar ◽  
M. Ilyas ◽  
F. S. Bhinder
Keyword(s):  
Experimental Study ◽  
Velocity Profiles ◽  
Pressure Recovery ◽  
Two Dimensional ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Velocity ◽  
Inlet Distortion ◽  
Mach Numbers ◽  
Inlet Flow Distortion

The results of an experimental study on the influence of severely distorted velocity profiles on the performance of a straight two-dimensional diffuser are reported. The data cover entry Mach numbers ranging from 0.1 to 0.6 and several inlet distortion levels. The pressure recovery progressively deteriorates as the inlet velocity is distorted.

The Effect of Non-Uniform Aerodynamic Loading on the Blade Responses

2007 ◽  
Author(s):  
Abdelgadir M. Mahmoud ◽  
Mohd S. Leong
Keyword(s):  
Turbine Blades ◽  
Forced Response ◽  
Flow Section ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Bladed Disk ◽  
Aerodynamic Loading ◽  
Bladed Disk Assembly ◽  
Flow Generator ◽  
Inlet Flow Distortion

Turbine blades are always subjected to severe aerodynamic loading. The aerodynamic loading is uniform and Of harmonic nature. The harmonic nature depends on the rotor speed and number of nozzles (vanes counts). This harmonic loading is the main sources responsible for blade excitation. In some circumstances, the aerodynamic loading is not uniform and varies circumferentially. This paper discussed the effect of the non-uniform aerodynamic loading on the blade vibrational responses. The work involved the experimental study of forced response amplitude of model blades due to inlet flow distortion in the presence of airflow. This controlled inlet flow distortion therefore represents a nearly realistic environment involving rotating blades in the presence of airflow. A test rig was fabricated consisting of a rotating bladed disk assembly, an inlet flow section (where flow could be controlled or distorted in an incremental manner), flow conditioning module and an aerodynamic flow generator (air suction module with an intake fan) for investigations under laboratory conditions. Tests were undertaken for a combination of different air-flow velocities and blade rotational speeds. The experimental results showed that when the blades were subjected to unsteady aerodynamic loading, the responses of the blades increased and new frequencies were excited. The magnitude of the responses and the responses that corresponding to these new excited frequencies increased with the increase in the airflow velocity. Moreover, as the flow velocity increased the number of the newly excited frequency increased.

Application of Aerodynamically Induced Prewhirl to a Small Turbocharger Compressor

1980 ◽  
Vol 102 (4) ◽  
pp. 943-950 ◽  
Author(s):  
N. Kyrtatos ◽  
N. Watson
Keyword(s):  
Mathematical Model ◽  
Design Procedure ◽  
Performance Data ◽  
Inlet Flow ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Compressor Performance

A design procedure is described which allows the development of an arrangement to aerodynamically impart prewhirl to the inflow of a compressor. The procedure uses compressor performance data and inducer inlet flow distributions together with a mathematical model of the aerodynamic prewhirl inducing arrangement to arrive at the parameters which completely define an arrangement suitable for a particular compressor. The application of the procedure to design an arrangement for a small turbocharger compressor is presented. The effect of the aerodynamically imparted prerotation on the compressor performance was found to be similar to that produced by inlet guide vanes.

Lip Separation and Inlet Flow Distortion Control in Ducted Fans Used in VTOL Systems

2014 ◽  
Author(s):  
Ali Akturk ◽  
Cengiz Camcı
Keyword(s):  
Angle Of Attack ◽  
Axial Flow ◽  
Vertical Force ◽  
High Angle ◽  
Flow Distortion ◽  
High Angle Of Attack ◽  
Inlet Flow ◽  
Flight Velocity ◽  
Ducted Fan ◽  
Inlet Flow Distortion

This paper describes a novel ducted fan inlet flow conditioning concept that will significantly improve the performance and controllability of ducted fan systems operating at high angle of attack. High angle of attack operation of ducted fans is very common in VTOL (vertical take off and landing) UAV systems. The new concept that will significantly reduce the inlet lip separation related performance penalties in the edgewise/forward flight zone is named DOUBLE DUCTED FAN (DDF). The current concept uses a secondary stationary duct system to control inlet lip separation related momentum deficit at the inlet of the fan rotor occurring at elevated edgewise flight velocities. The DDF is self-adjusting in a wide edgewise flight velocity range and its corrective aerodynamic effect becomes more pronounced with increasing flight velocity due to its inherent design properties. Most axial flow fans are designed for an axial inlet flow with zero or minimal inlet flow distortion. The DDF concept is proven to be an effective way of dealing with inlet flow distortions occurring near the lip section of any axial flow fan system, especially at high angle of attack. In this present paper, a conventional baseline duct without any lip separation control feature is compared to two different double ducted fans named DDF CASE-A and DDF CASE-B via 3D, viscous and turbulent flow computational analysis. Both hover and edgewise flight conditions are considered. Significant relative improvements from DDF CASE-A and DDF CASE-B are in the areas of vertical force (thrust) enhancement, nose-up pitching moment control and recovery of fan through-flow mass flow rate in a wide horizontal flight range.

Inlet Flow Distortion

2018 ◽  
pp. 249-267 ◽  
Author(s):  
Joachim Kurzke ◽  
Ian Halliwell
Keyword(s):  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Flow Distortion

Forward Swept Rotor Studies in Multistage Fans With Inlet Distortion

2002 ◽  
Author(s):  
A. R. Wadia ◽  
P. N. Szucs ◽  
D. W. Crall ◽  
D. C. Rabe
Keyword(s):  
Pressure Ratio ◽  
Flow Distortion ◽  
Two Stage ◽  
Good Efficiency ◽  
Guide Vanes ◽  
Stall Margin ◽  
High Pressure Ratio ◽  
Inlet Distortion ◽  
Inlet Guide Vanes ◽  
Current Production

Previous experimental and analytical studies conducted to compare the performance of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep with respect to aerodynamic performance and stability to multistage configurations. The experimental investigation compares, on a back-to-back test basis, two builds of an advanced good efficiency, high pressure ratio, two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained an already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs). The presence of the inlet guide vanes had a profound impact in lowering the two stage fan’s sensitivity with inlet distortion.

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