Mechanics Colloquium

PROGRAM

PROGRAM ZA FEBRUAR 2011.

Pozivamo Vas da učestvujete u radu sednica Odeljenja i to:

SREDA, 16. februar 2011. u 18 sati:

Lecture No 1142
dr Slavica Ristic, naucni savetnik, Institut Gosa, Beograd
Vizuelizacija strujanja

Flow Visualization

Abstract: Vizualizacija strujanja je veoma vazna oblast eksperimentalne aerodinamike kojoj je posvecen veliki broj istrazivanja. To je skup metoda koje koriste savremena dostignuca nauke i tehnike i pomazu da se vidi kretanje nevidljivih fluida oko vazduhoplovnih i nevazduhoplovnih objekata u laboratorijskim postrojenjima, aerodinamicnim i vodenim tunelima ili realnim uslovima. Savremeni razvoj kompjuterske tehnike i digitalna obrada slike omogucavaju automatsku analizu rezultata vizuelizacije strujanja i dobijanja kvalitativne i kvantitativne vrednosti strujnih parametara, koji ne mogu da se dobiju klasicnim, konvencionalnim tehnikama merenja. Najnoviji razvoj numerickih metoda dinamike fluida (CFD) cesto koristi rezultate vizuelizacije strujanja za proveru numerickih rezultata, kao i za komparativnu analizu eksperimentalne i numericke slike strujanja. Bice prikazan pregled metoda vizuelizacije strujanja, sa posebnim akcentom na opticke, odnosno laserske metode. To su holografska interferometrija (HI), laser Dopler anemometrija (LDA) i anemometrija na osnovu slike cestica(PIV). Rezultati istrazivanja, koji su realizovani u Vojnotehnickom institutu i na Masinskom fakultetu u Beogradu, ilustrovace primenu ovih metoda. Literatura: 1. Ristic S.,Flow visualization techniques in wind tunnels. Part I-Non optical Methods, STR.No.1, 2007, ISSN 1820-0206, edt.Stevan Maksimovic, www.vti.mod.gov.rs/ntp/index.htm 2. Ristic S.,Flow visualization techniques in wind tunnels. Part II-Non optical Methods, STR.No.2, 2007, ISSN 1820-0206, edt.Stevan Maksimovic, www.vti.mod.gov.rs/ntp/index.htm 3. Ristic S.,Laser Doppler Anemometry and its Application in Wind Tunnel Tests, Scientific Technical Review Vol.LVII,No.3-4.2007, 64-76. 4. M. Puharic, S. Ristic, M. Kutin, Z. Adamovic, Laser Doppler Anemometry in Hydrodynamic Testing, Journal of Russien Laser Research, Volume 28, Number 6, 2007, pp.619-628. 5. Puharic M., Kozic M., Kutin M., Ristic S., Hidro turbinau Venturijevoj cijevi, Strojarstvo, ZX470/1402, broj 5, Vol. 51, str. 441-448, 2009. 6. Kozic M., Ristic S., Capability of two dimensional Reynolds-averaged Navier-Stokes simulations for two dimensional thrust vectorizing nozzles, Proc. of Institute of Mech. Part G: J. Aerospace Engineering G, DOI: 10.1243/095441100JAERO676, Online ISSN 2041-3025, Print ISSN 0954-4100, vol 224, no. G8, pp 905-910 7. S. S. Ristic, Mirjana T. Puharic, Marina Kutin, Dusan Matic, Determination of Air and Hydrofoil Cp by Lase Doppler Anemometry, Theoret. Appl. Mech. Vol. 37, No.1, pp. 17-35, 2010, ISSN 1450-5584, edt.Veljko Vujicic 8. S. Ristic, M. Sreckovic, Testing of supersonic wind tunnel flow by holographic interferometry, Atti dela Fondazione Giorgio Ronchi, anno 61, march, 2006, pp.231-240 9. Ristic S., Kozic M., Puharic M., Experimental and Numerical Investigation of Flow separation in a Supersonic Nozzle, Journal of Russian Laser Research, Vol. 29, No. 4, 2008, pp-377-389 10. Ristic S., Optical methods in wind tunnel flow visualization, FME Transactions, 2007, vol. 34, n.1, pp.7-13

Abstract:
Flow visualization is a very important tool of experimental fluid mechanics. Numerous studies are devoted to flow visualization. This is a set of methods that use modern technology and help to "see" the invisible movement of air and fluid around aeronautical and non-aeronautical objects in laboratory facilities, wind and water tunnels, or in real conditions. The modern development of computers and digital image processing enable automated analysis of the flow visualization results and obtaining qualitative and quantitative values of flow parameters, which can't be obtained by classical, measurement techniques. Recent development of numerical methods, computer fluid dynamics (CFD), often uses the results of flow visualization to verify the numerical results and to make comparative analysis of experimental and numerical flow field.The flow visualization is equally important in computational as in experimental fluid dynamics. The review the most widely used methods for flow visualization will be presented and a considerable attention will be paid to describe optical, laser methods (especially optical and laser methods); holographic interferometry (HI), laser Doppler anemometry (LDA) and anemometry based on particle images (PIV). The results of researches, which were carried out at the Military Technical Institute and the School of Mechanical Engineering, illustrate presented methods.



SREDA, 23. februar 2011. u 18 sati:

Lecture No 1143
Prof. dr Tomislav Petrovic, D. Sc., Masinski fakultet Nis
THE NEW MODEL OF MECHANISM BASED ON A DYNAMIC COUPLING OF UNIFORM LINEAR OSCILLATORY MOTION WITH ONE-WAY ROTATATIONAL MOTION

Abstract: A new model of construction together with the principle of work of a dynamic system intended to transform uniform linear oscillatory motion into one-way rotatational motion is presented, which is protected by European patent EP labelled Nr. 1514026. The base of the model consists of two kinematically coupled mass points oscillating around the movable suspension points. The driving linear motion is enabled by means of pistons through the system of levers affecting the movable suspension points. The coupling of the elements performing linear and rotational movement is dynamic. It is a system with two degrees of freedom of movement which gives itself a flexiblility required to perform adjusting of thermodynamic parameters of the pistons moving within the cylinders with kinematic and kinetic parameters of the system. The „supernumerary“ degree of freedom is taken away from the system by means of a relevant mechatronic control method providing a controlled mechanism motion in this way. The new principle of motion transformation is described presenting also the basic concept nad mathematical equations referring to mutual interconnection between the dynamic and kinematic system parameters. The attention is drawn to the basic control principles of a new system of motion transformation together with the constructive derivations which may have practical application. A physical model representing the new motion transformation is made and its functioning is described.

Predavanja ce se odrzavati sredom sa pocetkom u 18.00 casova, u sali 301 F na trecem spratu zgrade Matematickog instituta SANU, Knez Mihailova 36/III, (zgrada preko puta glavne zgrade SANU).

Poziv naucnicima i istrazivacima da prijave svoja predavanja:
Prijava potencijalnog predavaca treba da sadrzi apstrakt predavanja do jedne stranice na srpskom jeziku cirilicom i prevod na engleski jezik, kao i CV obima do dve stranice. Prijavu poslati na adresu upravnika Odelenja za mehaniku u vidu Word DOC na adresu: khedrih@eunet.rs

Start of each lecture is at each Wednesday at 18,00 h in room 301 F at Mathematical Institute SANU, street Knez Mihailova 36/III.

Announcement and Invitation:
All scientists and researchers in area of Mechanics are invited to contribute to the Program of Mechanics Colloquium of Mathematical Institute of Serbian Academy of Sciences and Arts. One page Abstract of proposed Lecture with short CV is necessary to submit in world doc to Head of Department of Mechanics (address: khedrih@eunet.rs), one month before first day in the next month.