Experimental investigation of the interplay between the sound field and the flow field in skewed low-pressure axial fans

2019 ◽  
Vol 442 ◽  
pp. 220-236 ◽  
Author(s):  
Florian J. Krömer ◽  
Stéphane Moreau ◽  
Stefan Becker
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Sound Field ◽  
Low Pressure ◽  
Axial Fans

Experimental Investigation of the Steady and Unsteady Flow Field in a Single Stage Low Pressure Axial Compressor With a Circumferential Groove Casing Treatment

2010 ◽  
Author(s):  
N. Van de Wyer ◽  
B. Farkas ◽  
J. Desset ◽  
J. F. Brouckaert ◽  
J.-F. Thomas ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Unsteady Flow ◽  
Axial Compressor ◽  
Low Pressure ◽  
Fast Response ◽  
Single Stage ◽  
Compressor Stage ◽  
Casing Treatment ◽  
Circumferential Groove

This paper deals with the experimental investigation of the influence of a circumferential groove casing treatment on the performance and stability margin of a single stage low pressure axial compressor. The design of the compressor stage is representative of a booster stage for the new counter-rotating turbofan engine architecture and is characterized by unusually high loading and flow coefficients. The choice of the circumferential groove is described on the basis of a numerical parametric study on the number of grooves, the axial position, the depth and width of the groove. The experiments were performed at a Reynolds number corresponding to cruise conditions in the von Karman Institute closed loop high speed compressor test rig R4. The detailed performance characterization of the compressor stage with casing treatment was mapped at four operating points from choke to stall at design speed. The compressor stall limit was determined at several other off-design speeds. Detailed steady and unsteady measurements were performed to determine the flow field characteristics of the rotor and of the complete stage. Conventional pressure, temperature and directional probes were used along with fast response pressure sensors in the rotor casing and in the groove. Simultaneous traverses with a fast response total pressure probe were used to map the unsteady flow field at the rotor exit allowing an experimental capture of the tip leakage vortex path and extension through the rotor passage. A comparison of the flow features with and without casing treatment was performed and the results are discussed against 3D viscous computational predictions. The casing treatment did not present any improvement of the compressor stall margin but no significant performance degradation was observed either. The CFD predictions showed a good agreement with the measurements and their analysis supported the experimental results.

Numerical and Experimental Investigation of Flow-Acoustic Resonance of Side-by-Side Cylinders in a Duct

2013 ◽  
Author(s):  
Atef Mohany ◽  
David Arthurs ◽  
Michael Bolduc ◽  
Marwan Hassan ◽  
Samir Ziada
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Cross Flow ◽  
Sound Field ◽  
Acoustic Resonance ◽  
Acoustic Power ◽  
Bluff Bodies ◽  
Aerodynamic Sound ◽  
Spacing Ratio ◽  
Piping Systems

The phenomenon of flow-excited acoustic resonance is a design concern in many engineering applications, especially when wakes of bluff bodies are encountered in ducts, piping systems, heat exchangers, and other confined systems. In this article, the case of self-excited acoustic resonance of two side-by-side cylinders in a duct with cross-flow is investigated both numerically and experimentally. A single spacing ratio between the cylinders, T/D = 2.5, is investigated, where D is the diameter of the cylinders and T is the center-to-center distance between them. The numerical investigation is performed using a finite-volume method at a Reynolds number of 30,000 to simulate the unsteady flow field, which is then coupled with a finite element simulation of the resonant sound field. The experimental investigation is performed using phase-locked Particle Image Velocimetry (PIV) during the occurrence of flow-excited acoustic resonance. The results of both methods reveal that the flow-excited acoustic resonance produces a strong oscillatory flow pattern in the cylinder wakes with strong in-phase vortex shedding being synchronized by the excited acoustic resonance. The distribution and strength of the aeroacoustic sources and sinks within the flow field have been computed by means of Howe’s theory of aerodynamic sound for both the experimental and numerical cases, with the results of the two methods comparing favorably, showing similar trends in the oscillating flow fields, and very similar trends in the distribution of net acoustic power.

Experimental investigation of the 3D unsteady flow field downstream of axial fans

2006 ◽  
Vol 17 (5) ◽  
pp. 303-314 ◽  
Author(s):  
Gérald Kergourlay ◽  
Smaïne Kouidri ◽  
Gary W. Rankin ◽  
Robert Rey
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Unsteady Flow ◽  
Axial Fans ◽  
3D Unsteady Flow

scholarly journals Analysis of the Influence of Different Bionic Structures on the Noise Reduction Performance of the Centrifugal Pump

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 886
Author(s):  
Cui Dai ◽  
Chao Guo ◽  
Yiping Chen ◽  
Liang Dong ◽  
Houlin Liu
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Centrifugal Pump ◽  
Great Influence ◽  
Frequency Doubling ◽  
Sound Field ◽  
Internal Flow ◽  
Test System ◽  
Centrifugal Pumps ◽  
External Characteristics

The strong noise generated during the operation of the centrifugal pump harms the pump group and people. In order to decrease the noise of the centrifugal pump, a specific speed of 117.3 of the centrifugal pump is chosen as a research object. The bionic modification of centrifugal pump blades is carried out to explore the influence of different bionic structures on the noise reduction performance of centrifugal pumps. The internal flow field and internal sound field of bionic blades are studied by numerical calculation and test methods. The test is carried out on a closed pump test platform which includes external characteristics and a flow noise test system. The effects of two different bionic structures on the external characteristics, acoustic amplitude–frequency characteristics and flow field structure of a centrifugal pump, are analyzed. The results show that the pit structure has little influence on the external characteristic parameters, while the sawtooth structure has a relatively great influence. The noise reduction effect of the pit structure is aimed at the wide-band noise, while the sawtooth structure is aimed at the discrete noise of the blade-passing frequency (BPF) and its frequency doubling. The noise reduction ability of the sawtooth structure is not suitable for high-frequency bands.

Experimental Investigation of Transient Response and Turbocharger Coupling for High and Low Pressure EGR Systems

2014 ◽  
Vol 7 (2) ◽  
pp. 977-985 ◽  
Author(s):  
David Heuwetter ◽  
William Glewen ◽  
David E. Foster ◽  
Roger Krieger ◽  
Michael Andrie
Keyword(s):  
Experimental Investigation ◽  
Transient Response ◽  
Low Pressure
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