A comparative experimental analysis of two unsteady flow control methods in a highly loaded compressor cascade

2020 ◽  
Vol 61 (6) ◽  
Author(s):  
Hongxin Zhang ◽  
Shaowen Chen
Keyword(s):  
Unsteady Flow ◽  
Flow Control ◽  
Experimental Analysis ◽  
Control Methods ◽  
Compressor Cascade ◽  
Highly Loaded

A comparison of different unsteady flow control techniques in a highly loaded compressor cascade

2018 ◽  
Vol 233 (6) ◽  
pp. 2051-2065 ◽  
Author(s):  
Hongxin Zhang ◽  
Shaowen Chen ◽  
Yun Gong ◽  
Songtao Wang
Keyword(s):  
Unsteady Flow ◽  
Flow Control ◽  
Flow Separation ◽  
Synthetic Jet ◽  
Control Technique ◽  
Compressor Cascade ◽  
Optimum Result ◽  
Control Techniques ◽  
Constant Suction ◽  
Highly Loaded

A numerical research is applied to investigate the effect of controlling the flow separation in a certain highly loaded compressor cascade using different unsteady flow control techniques. Firstly, unsteady pulsed suction as a new novel unsteady flow control technique was proposed and compared to steady constant suction in the control of flow separation. A more exciting effect of controlling the flow separation and enhancing the aerodynamic performance for unsteady pulsed suction was obtained compared to steady constant suction with the same time-averaged suction flow rate. Simultaneously, with the view to further exploring the potential of unsteady flow control technique, unsteady pulsed suction, unsteady pulsed blowing, and unsteady synthetic jet (three unsteady flow control techniques) are analyzed comparatively in detail by the related unsteady aerodynamic parameters such as excitation location, frequency, and amplitude. The results show that unsteady pulsed suction shows greater advantage than unsteady pulsed blowing and unsteady synthetic jet in controlling the flow separation. Unsteady pulsed suction and unsteady synthetic jet have a wider range of excitation location obtaining positive effects than unsteady pulsed blowing. The ranges of excitation frequency and excitation amplitude for unsteady pulsed suction gaining favorable effects are both much wider than that of unsteady pulsed blowing and unsteady synthetic jet. The optimum frequencies of unsteady pulsed suction, unsteady pulsed blowing, and unsteady synthetic jet are found to be different, but these optimum frequencies are all an integer multiple of the natural frequency of vortex shedding. The total pressure loss coefficient is reduced by 16.98%, 16.55%, and 17.38%, respectively, when excitation location, frequency, and amplitude are all their own optimal values for unsteady pulsed suction, unsteady pulsed blowing, and unsteady synthetic jet. The optimum result of unsteady synthetic jet only slightly outperforms that of unsteady pulsed suction and unsteady pulsed blowing. But unfortunately, there is no advantage from the standpoint of overall efficiency for the optimum result of unsteady synthetic jet because the slight improvement has to require a greater power consumption than the unsteady pulsed suction and unsteady pulsed blowing methods.

Effect of Blade Aspiration Slot Configuration on the Aerodynamic Performance of a Highly Loaded Aspirated Compressor Cascade

2017 ◽  
Author(s):  
Longxin Zhang ◽  
Le Cai ◽  
Bao Liu ◽  
Jun Ding ◽  
Songtao Wang
Keyword(s):  
Flow Control ◽  
Flow Rate ◽  
Control Method ◽  
Active Flow Control ◽  
Experimental Studies ◽  
Aerodynamic Performance ◽  
Flow Path ◽  
Compressor Cascade ◽  
Flow Loss ◽  
Highly Loaded

As a promising active flow control method, boundary layer suction (BLS) can be used to enhance the aerodynamic performance of the highly-loaded compressor effectively, and due to this reason, extensive studies have been carried out on it. However, contrast to those abundant studies focusing on the flow control effects of BLS, little attention has been paid on the design method of the aspiration flow path. This work presents a 3-D steady numerical simulation on a highly-loaded aspirated compressor cascade. The aspiration slot is implemented at its best location based on the previous experimental studies and the aspiration flow rate is fix to 1.5% of the inlet massflow. The plenum configuration follows the blade shape and remains unchanged. One-side-aspiration manner is adopted to simplify the aspiration devices. Two critical geometry parameters, slot angle and slot width, are varied to study the effects of blade aspiration slot configuration on the cascade loss, radial distribution of the aspiration flow rate and inner flow structures within the aspiration flow path. Results show that the slot configuration does affect the cascade performance. In comparison with the throughflow performance, it is especially true once the flow loss caused by the aspiration flow path is also taken into account, and higher flow loss will be generated within the aspiration flow path if an inappropriate scheme is adopted. In the present investigation, apart from the cases with larger negative slot angle, a wider slot is more preferable to a narrower one, since it could enhance the aspiration capacity near the endwall regions and lower the dissipation loss within the aspiration flow path. In terms of the slot angle, a larger negative value, i.e., the slot direction more aligned with the incoming flow, is not beneficial to improve the throughflow performance, while concerning the flow loss yield by the aspiration flow path, a proper negative slot angle is always optimal.

Topological analysis of plasma flow control on corner separation in a highly loaded compressor cascade

2012 ◽  
Vol 28 (5) ◽  
pp. 1277-1286 ◽  
Author(s):  
Xiao-Hu Zhao ◽  
Yun Wu ◽  
Ying-Hong Li ◽  
Xue-De Wang ◽  
Qin Zhao
Keyword(s):  
Flow Control ◽  
Plasma Flow ◽  
Topological Analysis ◽  
Compressor Cascade ◽  
Corner Separation ◽  
Plasma Flow Control ◽  
Highly Loaded

scholarly journals Experimental and numerical results of active flow control on a highly loaded stator cascade

2011 ◽  
Vol 225 (7) ◽  
pp. 907-918 ◽  
Author(s):  
M Hecklau ◽  
C Gmelin ◽  
W Nitsche ◽  
F Thiele ◽  
A Huppertz ◽  
...  
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Numerical Results ◽  
Pressure Probe ◽  
Compressor Cascade ◽  
Time Resolved ◽  
Inlet Velocity ◽  
Wide Range ◽  
Active Flow ◽  
Highly Loaded

This article presents experimental and numerical results for a compressor cascade with active flow control. Steady and pulsed blowing has been used to control the secondary flow and separation characteristics of a highly loaded controlled diffusion airfoil. Investigations were performed at the design incidence for blowing ratios from approximately 0.7 to 3.0 (jet-to-inlet velocity) and a Reynolds number of 840 000 (based on axial chord and inlet velocity). Detailed flow field data were collected using a five-hole pressure probe, pressure taps on the blade surfaces, and time-resolved Particle Image Velocimetry. Unsteady Reynolds-averaged Navier–Stokes simulations were performed for a wide range of flow control parameters. The experimental and numerical results are used to understand the interaction between the jet and the passage flow. The benefit of the flow control on the cascade performance is weighted against the costs of the actuation by introducing an efficiency which takes the presence of the jets into account.

Active Flow Control Concepts on a Highly Loaded Subsonic Compressor Cascade: Résumé of Experimental and Numerical Results

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Christoph Gmelin ◽  
Vincent Zander ◽  
Martin Hecklau ◽  
Frank Thiele ◽  
Wolfgang Nitsche ◽  
...  
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Suction Side ◽  
Numerical Results ◽  
Pressure Probe ◽  
Control Parameters ◽  
Compressor Cascade ◽  
Wide Range ◽  
Active Flow ◽  
Highly Loaded

This paper presents experimental and numerical results for a highly loaded, low speed, linear compressor cascade with active flow control. Three active flow control concepts employing steady jets, pulsed jets, and zero mass flow jets (synthetic jets) are investigated at two different forcing locations: at the end walls and the blade suction side. Investigations are performed at the design incidence for jet-to-inlet velocity ratios of approximately 0.7 to 3.0 and two different Reynolds numbers. Detailed flow field data are collected using a five-hole pressure probe, pressure tabs on the blade surfaces, and time-resolved particle image velocimetry. Unsteady Reynolds-Averaged Navier-Stokes simulations are performed for a wide range of flow control parameters. The experimental and numerical results are used to understand the interaction between the jet and the passage flow. Variation of jet amplitude, forcing frequency and blowing angle of the different control concepts at both locations allows determination of beneficial control parameters and offers a comparison between similar control approaches. This paper combines the advantages of an expensive yet reliable experiment and a fast but limited numerical simulation. Excellent agreement in control effectiveness is found between experiment and simulation.

The Cost of Flow Control in a Compressor

2011 ◽  
Author(s):  
Simon W. Evans ◽  
Howard P. Hodson
Keyword(s):  
Boundary Layer ◽  
Flow Control ◽  
Vortex Generator ◽  
Control Methods ◽  
Compressor Cascade ◽  
Suction Surface ◽  
Boundary Layer Suction ◽  
Blade Row ◽  
Efficiency Increase ◽  
The Cost

This paper documents an analysis performed to estimate the cycle cost of flow control in a compressor. The analysis is based on a series of experiments conducted in a low-speed compressor cascade at high incidence. In these experiments, flow control was applied to delay a turbulent separation on the suction surfaces of the blades in the cascade. The flow control methods studied include boundary layer suction and both steady and pulsed vortex generator jets. Endwall control was also applied to remove corner separations. Tip gaps and endwall suction were both studied for this purpose. The flow control methods studied were able to successfully delay a separation occurring on the suction surface of the blades, reducing the loss coefficient. The mass flow rates and jet supply pressures required to achieve control in each case were used to model a single flow-controlled blade row in a typical turbofan cycle using cycle analysis software. The cost of control to the cycle was calculated as the polytropic compressor efficiency increase required to maintain thrust relative to a conventional cycle with no flow control. The results of the analysis show that the benefits of flow control significantly outweigh the cost. They also show that boundary layer suction coupled with endwall suction yields the lowest cycle cost. This is because of the small pressure difference required to drive suction, which allows reinjection of the aspirated air a short distance upstream of the flow controlled blade row.

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