Stabilna stanja zaprtega sistema povezanih lupin

Matoh, Anja (author), Brojan, Miha (mentor)

Raziskujemo stabilna stanja dveh preko cevi z ventilom povezanih balonov, ki sta napolnjena z različnim tlakom. Ko ventil odpremo, med balonoma steče tok zraka, dokler se tlaka ne izenačita. To stanje je lahko stabilno ali pa ne. Stabilnost razumemo kot zmožnost, da ostane sistem v ravnovesju kljub manjši motnji. Najprej smo z eksperimentom prišli do karakteristike obravnavanih balonov. Merili smo tlak z merilnikom tlaka in prostornino s pomočjo programa za merjenje dimenzij na posnetih fotografijah balona. Nato smo izrisali še teoretično krivuljo z uporabo Mooney-Rivlinovega reološkega modela. Sledila je primerjava teh dveh krivulj in analiza stabilnosti. Zapisali smo tudi program, ki računa pretok zraka in prikazuje spremembo tlaka v balonih. Prišli smo do ugotovitve, da je stabilnost pogojena z naklonom karakteristične krivulje.

• Language: Slovenian
• Keywords: elastične lupine, tlak, volumski pretok, stabilnost, polimeri
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [A. Matoh]
• Year: 2019
• Number of pages: XIII, 36 f.
• PID: 20.500.12556/RUL-110011
• UDC: 532.11:531.787:678(043.2)
• COBISS.SI-ID: 16935963
• Publication date in RUL: 11.09.2019

Secondary language

• Language: English
• Title: Stable states in a closed system of interconnected shells

Abstract

We investigated the steady states of two valve-connected balloons with different pressure. When the valve is opened, the air flows between the balloons until the pressure in the balloons equalizes. This condition may or may not be stable. Stability is understood as the ability to keep the system in balance despite a minor disturbance. To determine the characteristics, we first carried out the experiment. We measured the pressure and volume using image measurement software. Next, we plotted a theoretical curve using the Mooney-Rivlin rheological model. A comparison of these two curves and an analysis of stability followed. We also wrote a program which calculates the flow of air and shows the change in pressure in the balloons. We concluded that the slope of the characteristic curve conditions the stability.

• Keywords: elastic shells, pressure, volume flow, stability, polymers