magistrsko delo
Juš Polanšek (Author), Uroš Cvelbar (Mentor), Samo Kralj (Co-mentor)

Abstract

Površinsko razelektritev na dielektrični pregradi dobimo, ko na dve elektrodi, ločeni z dielektrikom, priključimo visoko električno napetost. Zrak v bližini elektrode se ionizira in tvori hladno atmosfersko plazmo. V električnem polju ustvarjeni in pospešeni nabiti delci trčijo z nevtralnimi delci in jim prenesejo gibalno količino, zaradi česar se zrak nad dielektrikom začne premikat, kar povzroči potisno silo. Na tem področju še vedno ni dobro raziskano, kako debelina dielektrika in razdalja med elektrodama vplivata na potisno silo, še posebej pri višjih frekvencah, kot je 20 kHz. Iz dostopne literature je razvidno, da potisna sile še ni bila neposredno izmerjena in tudi ne analiziran njen časovni potek. V magistrskem delu smo se zato odločili, da eksperimentalno preučimo potisno silo. Raziskovali smo, kako različne geometrijske lastnosti in termični pojavi vplivajo na potisno silo pri površinski razelektritvi na dielektrični pregradi. Ugotovili smo, da je pri enakih amplitudah električne napetosti potisna sila večja na tanjšem dielektriku in da se sila veča, ko uporabimo tanjšo izpostavljeno elektrodo. Pri uporabi ožje izolirane elektrode smo opazili, da na določenem območju sila neha naraščati, kljub temu da se napetost še vedno veča. Sklepamo, da je razlog za ta pojav nasičenje ionskega oblaka nad dielektrikom. Izmerili smo, da je sila največja, če sta elektrodi izmaknjeni za približno 1 mm. Optimalna razdalja je v okviru merske napake ostala enaka pri različnih jakostih napetosti in dveh širinah izolirane elektrode. Določili smo smer potisne sile na ▫$8°2°$▫ glede na površino dielektrika in ugotovili, da smer ni odvisna od amplitude električne napetosti in širine izolirane elektrode. Izmerili smo časovni potek sile in temperature na dielektrikih različnih debelin in ugotovili, da je padanje sile s časom povezano s segrevanjem plina zraka nad površino dielektrika. To smo preverili tudi z analizo števila in amplitud razelektritev iz električnega toka, izmerjenega z osciloskopom. Izvedene meritve in znanstvena spoznanja iz tega dela bodo uporabna predvsem za regulacijo zračnega toka v različne namene.

Keywords

magistrska dela;atmosferska hladna plazma;površinska razelektritev na dielektrični pregradi;potisna sila;visoka električna napetost;razelektritev zraka;geometrijski parametri razelektritve;termični pojavi v plazmi;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FNM - Faculty of Natural Sciences and Mathematics
Publisher: [J. Polanšek]
UDC: 621.365.3:621.3.036.61(043.2)
COBISS: 164744195 Link will open in a new window
Views: 4
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Other data

Secondary language: English
Secondary title: Thrust force generated by surface dielectric barrier discharge
Secondary abstract: Surface dielectric barrier discharge (SDBD) is generated by applying a high-voltage electrical field across two electrodes that are separated by a dielectric material. This ionizes the air near the electrode, resulting in cold atmospheric plasma. Charged particles, accelerated in the electric field, collide with neutral particles, transferring momentum and thereby inducing a thrust force above the dielectric. Research in the domain of SDBD still has gaps in understanding the impact of dielectric thickness and the distance between electrodes on the generated thrust force, particularly at higher frequencies such as 20 kHz or above. In the existing literature, neither the direction of this force nor its temporal characteristics were directly measured. For this reason, we decided in this masters thesis to experimentally examine the thrust force and close the existing knowledge gap. The experimental investigation was focused on geometric variables of discharges and even phenomena that can influence the thrust force and its temporal behavior in such in SDBD. We discovered that a thinner dielectric yields a greater thrust force at equivalent voltage amplitudes and that the force increases when a thinner exposed electrode is used. When employing a narrower insulated electrode, we observed a plateau in the increase of the thrust force beyond a specific voltage range, which was attributed to the saturation of the ionic cloud above the dielectric. Our measurements indicate that the maximum thrust force occurs when the electrodes are offset by approximately 1 mm, a distance that remained optimal across different voltage levels and insulated electrode widths. We determined that the thrust force direction is ▫$8°2°$▫ relative to the dielectric surface and is not influenced by the amplitude or width of the insulated electrode. Temporal analysis of the force and temperature on dielectrics of varying thickness revealed that the decline in the force over time correlates with the air gas heating above the dielectric surface. This was confirmed by oscilloscope measurements of the number and amplitude of electrical discharges. The performed measurements and obtained scientific results from this thesis will be helpful for airflow regulation in different applications.
Secondary keywords: master theses;cold atmospheric plasma;surface dielectric barrier discharge;thrust force;high voltage;air discharge;discharge geometric parameters;thermal phenomena in plasma;Razelektrenje;Univerzitetna in visokošolska dela;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za naravoslovje in matematiko, Oddelek za matematiko in računalništvo
Pages: 34 str.
ID: 19889044