Frekventni odziv turbulentnog osnosimetriчnog mlaza vazduha na modifikaцijy zvuчnim osцilaцijama iz spoљaшњeg izvora pobude

0394555 - ÚCHP 2014 RS hbs J - Článek v odborném periodiku
Cvetinović, D. - Čantrak, S. - Tihon, Jaroslav - Drahoš, Jiří
Frekventni odziv turbulentnog osnosimetriчnog mlaza vazduha na modifikaцijy zvuчnim osцilaцijama iz spoљaшњeg izvora pobude.
[Frequency Response of Turbulent Axisymmetric Air Jet on Externaly Supplied Acoustic Oscillations Modification.]
Termotehnika. 205-219, 3-4 (2009), s. 205-219. ISBN 0350-218X
Výzkumný záměr: CEZ:AV0Z40720504
Klíčová slova: turbulent axisymmetric jet * acoustic oscillations modification * impinging jet heat transfer
Kód oboru RIV: CI - Průmyslová chemie a chemické inženýrství

Predmet istra`ivawa je turbulentni osnosimetri~ni mlaz vazduha koji isti~e u mirnu okolnu sredinu, fluida istih karakteristika, iz mlaznica razli~itog oblika, koji udara o ravnu zagrejanu podlogu postavqenu normalno na osu mlaza. Ciq istra`ivawa je da se eksperimentalno dubqe istra`i i objasni uticaj zvu~nih oscilacija na karakteristike mlaza kao i vrtlo`nih struktura u turbulentnom osnosimetri nom mlazu i da se ispita mogu}nost kontrole vrtlo - nih struktura za koje se pretpostavqa da imaju dominantnu ulogu u procesu prenosa toplote. Kao sredstvo kontrole vrtlonih struktura u mlazu su koriene na veta ki nain izazvane modulacije brzine mlaza na izlazu iz mlaznice. U radu su prikazani rezultati dela eksperimentalnog istraivawa koje je obavqeno u Institutu za hemijske procese Akademije nauka Ceske Republike u Pragu, uz koriewe spoqaweg izvora zvunih oscilacija za modifikaciju mlaza. Frekventni odziv turbulentnog osnosimetrinog mlaza vazduha na modifikaciju zvunim oscilacijama moemo videti uporeivawem profila filterovanih signala brzine uskopropusnim filterom sa profilima u slobodnom mlazu i pri udaru o ravnu podlogu. Prikazani profili nam omogu ujuda odredimo koji deo oscilacija u modifikovanom turbulentnom osnosimetrinom mlazu je odgovoran za maksimume u profilima intenziteta turbulencije.

The subject of this work is the submerged, round, unconfined turbulent axisymmetric jet, which is sues from nozzles with different geometries and impinges to the flat heated plate positioned normally to the jet axis. The aim of experimental investigations is to widely investigate properties and the vortex structures, that are as sumed to have great importance in the heat transfer process, of the modi fied turbulent axisymmetric jet by acoustic modulations and, additionally, to study the possibility of their control. The considered mean of vortex struc tures control is a modulation of the nozzle exit velocity using external source of low-amplitude oscillations and self-sustained oscillations generated in the operation of the specially designed nozzles. Experimental in vestigation of turblent axisymmetric jet modification by external excitations that were provided at the In stitute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Prague, Czech Republic, are presented in the paper investigation of turbulent axisymmetric jet modification by external excitations that were provided at the Institute of Chemical Process Fundamenals, Academy of Sciences of the Czech Repubic, Prague, are presented in the paper.
Trvalý link: http://hdl.handle.net/11104/0222809