Cavitation in Microfluidics

Kavitace v mikrofluidice

Academic Year:2015 / 2016

Martin HOLUBSupervisor:

doc. Ing. Pavel RUDOLF, Ph.D.

„Time is the most valuable thing a man can spend.“Theophrastus (370–285 BC)

Cavitation Microfluidics

Cavitation on hydrofoil [1] Microfluidic chip [2]

Thesis Goals

• Introduction, definition of fundamental terms

• Literature research and report on the state-of-the-art technology

• CFD for the flow in micrometer-sized channel

• Design of experiment

Cavitation Chemistry & Other Effects

Luminescence [5]

Single bubble collapse near the wall [4]

…… 𝐻2𝑂2

𝐻 • 𝑂𝐻•

𝐻2𝑂Energy

Mechanical, heat and chemical effects→ Applications

Luminescence [5]

Single bubble collapse near the wall [4]

Cavitation Chemistry & Other Effects

…… 𝐻2𝑂2

𝐻 • 𝑂𝐻•

𝐻2𝑂Energy

Mechanical, heat and chemical effects→ Applications

Luminescence [5]

Single bubble collapse near the wall [4]

…… 𝐻2𝑂2

𝐻 • 𝑂𝐻•

𝐻2𝑂Energy

Cavitation Chemistry & Other Effects

Mechanical, heat and chemical effects→ Applications

Microscale Cavitation

Bubbles completely filling microchannel [6]

Cases relevant for comparison [6], inception,

choking

𝜎=𝑝𝐷𝑆−𝑝𝑣

12𝜌𝑣𝑐

2

Device Description

0.284 0.242

0.38 0.299

0.24 0.171

0.301 0.252

Microchannel

𝑅𝑒𝑐=𝜌𝑣 ∙𝐿𝑐

𝜇 [− ]

Case No.

#1 102.5 0.365#2 130 0.415#3 158 0.465#4 186.5 0.515#5 213 0.565#6 241 0.615

Dimensions of microchannel, given in micrometers. BCs locations and types are indicated

Overview of solved cases

Solution Monitor – Vapor Fraction Fast Fourier Transform

Microchannel

Stable liquid jet surrounded by two broad and long vapor bubbles that

touch the walls [7]

Wavy pattern of cavity boundary [6]

𝜎=0.365

Microchannel

Vapor Volume Fraction Frequency

Microchannel

Millichannel

Millichannel geometry and BCs, all dimensions in micrometers

Case No.#1 14 5.67#2 20 2.95#3 60 0.53

Overview of solved cases

Vapor fraction = 0.2 in brick-

shaped chamber

𝜎=0.53

Vapor fraction in constriction,

high void fraction in red

Millichannel

Pressure dropTemperature of bubble

collapse

Source: [8]

Millichannel

Design of Experiment

Microfluidic channel with packaging module (Courtesy of D. Jasikova TUL)

Schematics of experimental setup

Design of Experiment

Main Outcomes• Recommendations for

future research work• Periodicity of solution• Strengths and weaknesses

of laminar model• Design of experimental

setup and procedure with μ-PIV

• Phases distribution• Regions of recirculation

and potential mixing• Overview of state-of-the-art

research• CFD guidelines for future

students

Sources of Images[1] FRANC, Jean-Pierre a Jean-Marie MICHEL. Fundamentals of cavitation. Dordrecht: Springer Netherlands, 2005, xxii, 300 p. ISBN 978-904-8166-183.

[2] news.stanford.edu/news/2006/january18/gifs/fluidicschip.jpg

[3] GOGATE, Parag, Irfan SHIRGAONKAR, M. SIVAKUMAR, P. SENTHILKUMAR, Nilesh VICHARE and Aniruddha PANDIT Cavitation reactors: Efficiency assessment using a model reaction. AIChE Journal [online]. Hoboken: Wiley Subscription Services, Inc., A Wiley Company, 2001, 47(11), 2526-2538 [cit. 2015-12-19]. DOI: 10.1002/aic.690471115. ISSN 00011541.

[4] brookbubble.weebly.com/uploads/7/8/1/6/78160850/5575735.gif

[5] DUPLAT, Jérôme a Emmanuel VILLERMAUX. Luminescence from Collapsing Centimeter Bubbles Expanded by Chemical Reaction. Physical review letters [online]. 2015, 115(9), 094501 [cit. 2016-

06- 06].

[6] MISHRA, C. a Y. PELES Size scale effects on cavitating flows through microorifices entrenched in rectangular microchannels. Microelectromechanical Systems, Journal of [online]. USA: IEEE, 2005, 14(5), 987-999 [cit. 2015-12-19]. DOI: 10.1109/JMEMS.2005.851800. ISSN 10577157.

[7] MISHRA, Chandan a Yoav PELES. Flow visualization of cavitating flows through a rectangular slot micro-orifice ingrained in a microchannel. Physics of Fluids [online]. AIP, 2005, 17(11), 13602-13616 [cit. 2016-04- 10]. DOI: 10.1063/1.2132289. ISSN 10706631.

[8] ROOZE, Joost, Matthieu ANDRÉ, Gert-Jan GULIK, David FERNÁNDEZ-RIVAS, Johannes GARDENIERS, Evgeny REBROV, Jaap SCHOUTEN a Jos KEURENTJES. Hydrodynamic cavitation in microchannels with channel sizes of 100 and 750 micrometers. Microfluidics and Nanofluidics [online]. Berlin/Heidelberg: Springer-Verlag, 2012, 12(1), 499-508 [cit. 2015-12-19]. DOI: 10.1007/s10404-011-0891-5. ISSN 16134982.