scholarly journals Flow control of weakly non-parallel flows: application to trailing vortices

2017 ◽  
Vol 822 ◽  
pp. 342-363 ◽  
Author(s):  
F. Viola ◽  
E. Pezzica ◽  
G. V. Iungo ◽  
F. Gallaire ◽  
S. Camarri
Keyword(s):  
Flow Control ◽  
Flow Condition ◽  
Amplification Factor ◽  
Base Flow ◽  
Flow Dynamics ◽  
Inlet Flow ◽  
Flow Modification ◽  
Parallel Flows ◽  
Trailing Vortices ◽  
Sensitivity Map

A general formulation is proposed to control the integral amplification factor of harmonic disturbances in weakly non-parallel amplifier flows. The sensitivity of the local spatial stability spectrum to a base-flow modification is first determined, generalizing the results of Bottaro et al. (J. Fluid Mech., vol. 476, 2003, pp. 293–302). This result is then used to evaluate the sensitivity of the overall spatial growth to a modification of the inlet flow condition. This formalism is applied to a non-parallel Batchelor vortex, which is a well-known model for trailing vortices generated by a lifting wing. The resulting sensitivity map indicates the optimal modification of the inlet flow condition enabling the stabilization of the helical modes. It is shown that the control, formulated using a single linearization of the flow dynamics carried out on the uncontrolled configuration, successfully reduces the total spatial amplification of all convectively unstable disturbances.

Design and performance evaluation of a pump-as-turbine micro-hydro test facility with incorporated inlet flow control

2015 ◽  
Vol 78 ◽  
pp. 1-6 ◽  
Author(s):  
D.R. Giosio ◽  
A.D. Henderson ◽  
J.M. Walker ◽  
P.A. Brandner ◽  
J.E. Sargison ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Flow Control ◽  
Test Facility ◽  
Inlet Flow ◽  
And Performance

scholarly journals Effects of Side Walls on Pipe Inlet Flow (Drag Reduction by Separated Flow Control Using Ring Shaped Small Obstacle)

2009 ◽  
Vol 4 (2) ◽  
pp. 468-478 ◽  
Author(s):  
Toshitake ANDO ◽  
Toshihiko SHAKOUCHI ◽  
Hiroyuki YAMAMOTO ◽  
Koichi TSUJIMOTO
Keyword(s):  
Drag Reduction ◽  
Flow Control ◽  
Separated Flow ◽  
Inlet Flow ◽  
Side Walls ◽  
Flow Drag ◽  
Small Obstacle ◽  
Pipe Inlet

Experimental Investigation of the Effect of the Probe Support Tail Structure on the Compressor Cascade Flow Field

2019 ◽  
Vol 36 (1) ◽  
pp. 9-18
Author(s):  
Honghui Xiang ◽  
Ning Ge ◽  
Jie Gao ◽  
Rongfei Yang ◽  
Minjie Hou
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Flow Condition ◽  
Test Facility ◽  
Axial Distance ◽  
Compressor Cascade ◽  
Inlet Flow ◽  
Disturbance Intensity ◽  
Cascade Flow ◽  
Tail Structure

Abstract Aiming at resolving the problem of measuring probe blockage effect in the performance experiments of high loaded axial flow compressors, an experimental investigation of the probe support disturbance effect on the compressor cascade flow field was conducted on a transonic plane cascade test facility. The influence characteristics of the probe support tail structure on the cascade downstream flow field under different operation conditions were revealed through the detailed analysis of the test data. The results show that the aerodynamic coupling effect between the upstream probe support wake and the downstream cascade flow field is very intense. Some factors, i. e. inlet Mach number, probe support tail structure, circumferential installing position of probe, and axial distance from the probe support trailing edge to the downstream cascade, are found to have the most impact on the probe disturbance intensity. Under high speed inlet flow condition, changing probe support tail structure can’t inhibit probe support disturbance intensity effectively. Whereas under low speed inlet flow condition, compared with the cylindrical probe, the elliptic probe can inhibit probe support wake loss and reduce disturbance effects on the downstream cascade flow field.

Transition Modeling Effects on the Simulation of a Stator Cascade With Active Flow Control

2008 ◽  
Author(s):  
Dirk Mertens ◽  
Frank Thiele ◽  
Marius Swoboda ◽  
Andre´ Huppertz
Keyword(s):  
Flow Control ◽  
Mass Flow ◽  
Active Flow Control ◽  
Base Flow ◽  
Experimental Measurements ◽  
Transition Model ◽  
Transition Effects ◽  
Transition Modeling ◽  
Active Flow ◽  
Varying Mass

An investigation of a stator cascade is undertaken by means of steady 3D RANS simulations, the focus of which is on two computational setups. The first takes transition effects into account using a correlation-based transition model as suggested by Abu-Ghannam and Shaw, while the second is considered to be fully turbulent. In a first step the base flow is validated by experimental measurements, followed by configurations employing active flow control by means of steady jets with varying mass flow. By investigating the differences arising due to the varying level of modeling complexity the necessity of using a transition model can be illustrated.

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