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A Numerical Study of the Relation Between the Acoustic Generator Geometry and the Heat Transfer Conditions

Rulik S., Wróblewski W., Rusin K.

Archive of Mechanical Engineering

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2018

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Vol. LXV, nr 1

5--26

EN

Modern gas turbine systems operate in temperatures ranging from 1200°C to even 1500°C, which creates bigger problems related to the blade material thermal strength. In order to ensure appropriate protection of the turbine blades, a sophisticated cooling system is used. Current emphasis is placed on the application of non-stationary flow effects to improve cooling conditions, e.g., the unsteady-jet heat transfer or the heat transfer enhancement using high-amplitude oscillatory motion. The presented research follows a similar direction. A new concept is proposed of intensification of the heat transfer in the cooling channels with the use of an acoustic wave generator. The acoustic wave is generated by an appropriately shaped fixed cavity or group of cavities. The phenomenon is related to the coupling mechanism between the vortex shedding generated at the leading edge and the acoustic waves generated within the cavity area. Strong instabilities can be observed within a certain range of the free flow velocities. The presented study includes determination of the relationship between the amplitude of acoustic oscillations and the cooling conditions within the cavity. Different geometries of the acoustic generator are investigated. Calculations are also performed for variable flow conditions. The research presented in this paper is based on a numerical model prepared using the Ansys CFX-17.0 commercial CFD code.

2

Hałas emitowany przez elektrownie wiatrowe

Zwolińska-Mańczak A.

Czysta Energia

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2012

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Nr 11

16-17

3

Zastosowanie foliowej sondy dwuwłóknowej do pomiarów turbulencji

Kaiser M., Wierciński Z.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

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2000

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nr 117, vol. 2

73-79

PL

Termoanemometryczne sondy foliowe, przede wszystkim ze względu na ich trwałość, znajdują coraz częstsze zastosowanie. Jednakże ich właściwości dynamiczne nie są poznane dostatecznie dobrze. Badania przedstawione w niniejszej pracy wskazują na wysoki poziom szumów własnych tej sondy spowodowany śladem aerodynamicznym i czujnika. Badania przeprowadzono w strumieniu o niskim poziomie turbulencji i , porównano z pomiarami turbulencji wykonanymi zwykłą jednowłóknową sondą termoanemometryczną. Szum aerodynamiczny sondy foliowej jest ponad 25 razy większy od szumu sondy z grzanym drutem. Fakt ten należy uwzględnić przy wykorzystaniu tych sond do pomiarów turbulencji.

EN

Application of the split-fiber probes in the experiments steadily rises mostly due to , their durability. Their dynamics characteristics are rather not well recognized. Investigations presented in this paper point at the high level of aerodynamics noise of these probes, caused mainly by the How around they. Measurements were made in stream of the very low level of turbulence and compared with results of the hot-wire probe. The aerodynamic noise (velocity fluctuations caused by the probe) and its spectra were measured. The aerodynamic noise of the split-fiber probes is more than 25 times greater than that of the hot-wire probe. This fact is to be taken into consideration for measurements of turbulence by means of split-fiber probes.