Experimental setups for studying homogeneous-isotropic and rotating turbulence in clay suspensions: Preliminary results

Tipnis, Vaibhav Vinay

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https://hdl.handle.net/2142/108176 Copy

Description

Title

Experimental setups for studying homogeneous-isotropic and rotating turbulence in clay suspensions: Preliminary results

Author(s)

Tipnis, Vaibhav Vinay

Issue Date

2020-05-13

Director of Research (if dissertation) or Advisor (if thesis)

• Chamorro, Leonardo P
• Best, Jim

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Homogeneous-isotropic turbulence
• Laponite clay suspension
• PIV
• non-Newtonian fluid
• Taylor-Couette flow

Abstract

Homogeneous and isotropic turbulence (HIT) has been at the center of a vast span of research seeking fundamental understanding and insights on the phenomenon of turbulence, which is ubiquitous in nature as well as engineering. The HIT assumption greatly simplifies the analytical treatment of turbulence, however creating truly HIT conditions in experiments has still remained a challenge and most research has focused on Newtonian fluids. Here we uses two different approaches to create HIT in water and aqueous suspension of Laponite clay, a shear-thinning fluid. The first approach involving flow actuators placed symmetrically around an enclosed volume has been used by past studies for creating small regions of HIT in gaseous media. We show using planar particle image velocimetry that our HIT setup is capable of producing low Taylor microscale Reynolds number HIT region of 20 mm x 20 mm in liquid media. Comparison of temporal spectra in water and aqueous clay suspension cases showed that presence of clay significantly alters the scaling of the inertial subrange and increases the Taylor microscale Reynolds number, in addition to suppressing the mean flow. The second approach uses random actuation of jets to stir fluid in a tank, which has been used by past studies to create large HIT regions. We have built a smaller version of this concept with the aim to create high Taylor microscale Reynolds number flow in water and clay suspensions.

Graduation Semester

2020-05

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/108176

Copyright and License Information

Copyright 2020 Vaibhav Vinay Tipnis

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