Heat Transfer Enhancements from Elastic Turbulence Using Sucrose-Based Polymer Solutions

Ligrani, Phil; Copeland, Daniel; Ren, Chong; Su, Mengying; Suzuki, Masaaki

doi:10.2514/1.t5161

Cited by 17 publications

(18 citation statements)

References 20 publications

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“…Mixing in microfluidic channels is typically diffusion‐limited because of the low Reynolds numbers, but elastic flow instabilities have been shown to dramatically improve the speed of mixing . Similarly, this enhanced mixing can be leveraged for improved heat transfer in other industrial processes that require low Reynolds numbers …”

Section: Discussionmentioning

confidence: 99%

“…[226,227] Similarly, this enhanced mixing can be leveraged for improved heat transfer in other industrial processes that require low Reynolds numbers. [228] Other Applications: Most studies focus on polymer solution flows in the context of oil recovery and groundwater remediation. However, the work described in this review article may also be relevant to other applications that seek to use polymer solutions in porous media: filtration, [229] fabrication of new materials, thin film processing, [230] extrusion of polymers during 3D-printing, [231,232] and novel forms of chromatography.…”

Section: Discussionmentioning

confidence: 99%

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Pore‐Scale Flow Characterization of Polymer Solutions in Microfluidic Porous Media

Browne

Shih

Datta

2019

Small

103

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Polymer solutions are frequently used in enhanced oil recovery and groundwater remediation to improve the recovery of trapped nonaqueous fluids. However, applications are limited by an incomplete understanding of the flow in porous media. The tortuous pore structure imposes both shear and extension, which elongates polymers; moreover, the flow is often at large Weissenberg numbers, Wi, at which polymer elasticity in turn strongly alters the flow. This dynamic elongation can even produce flow instabilities with strong spatial and temporal fluctuations despite the low Reynolds number, Re. Unfortunately, macroscopic approaches are limited in their ability to characterize the pore‐scale flow. Thus, understanding how polymer conformations, flow dynamics, and pore geometry together determine these nontrivial flow patterns and impact macroscopic transport remains an outstanding challenge. This review describes how microfluidic tools can shed light on the physics underlying the flow of polymer solutions in porous media at high Wi and low Re. Specifically, microfluidic studies elucidate how steady and unsteady flow behavior depends on pore geometry and solution properties, and how polymer‐induced effects impact nonaqueous fluid recovery. This work thus provides new insights for polymer dynamics, non‐Newtonian fluid mechanics, and applications such as enhanced oil recovery and groundwater remediation.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Pore‐Scale Flow Characterization of Polymer Solutions in Microfluidic Porous Media

Browne

Shih

Datta

2019

Small

103

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“…Instabilities due solely to the inherent elasticity of the fluid have been discovered in a wide number of flows over roughly the past three decades. [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] In these flows, the streamlines are generally curved, and the instabilities are thought to occur as perturbations are amplified as they are coupled to the hoop stress associated with the mean flow. However, recent experiments 55,56 have revealed instabilities in the flow of a viscoelastic fluid within microchannels with rectilinear streamlines.…”

Section: Effects Of Fluid Elasticitymentioning

confidence: 99%

“…In fact, this does not turn out to be the case. Instabilities due solely to the inherent elasticity of the fluid have been discovered in a wide number of flows over roughly the past three decades . In these flows, the streamlines are generally curved, and the instabilities are thought to occur as perturbations are amplified as they are coupled to the hoop stress associated with the mean flow.…”

Section: Introductionmentioning

confidence: 99%

Vortex generation in a finitely extensible nonlinear elastic Peterlin fluid initially at rest

Handler

Blaisten‐Barojas

Ligrani

et al. 2020

Engineering Reports

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It is well known that the mixing of two or more species in flows at low Reynolds numbers cannot be easily achieved since inertial effects are essentially absent and molecular diffusion is slow. To achieve mixing in Newtonian fluids under these circumstances requires innovative new ideas such as the use of external body forces (eg, electromagnetic mixers) or the stretching and folding of fluid elements (eg, chaotic advection). For non‐Newtonian fluids with elasticity, mixing can be achieved by enabling the emergence of elastic instabilities that results in chaotic flows in which mixing is significantly enhanced. In this work, our goal is to demonstrate that clearly identifiable vortical structures (eg, vortex rings) can be generated in a viscoelastic fluid initially at rest by the release of elastic stresses. In turn, these vortex motions promote bulk mixing by transporting fluid elements from one location to another more efficiently than diffusion alone. We demonstrate this first theoretically by using the finitely extensible nonlinear elastic Peterlin (FENE‐P) model to show that elastic forces can generate torque. Using this model, we derive an expression for the time rate of change of vorticity in an elastic fluid initially at rest caused by a sudden release of stored elastic stress. This process can be thought of as the release of elastic energy from a stretched rubber band that is suddenly cut at its center. We confirm this ansatz by performing a series of direct numerical simulations based on an in‐house pseudo‐spectral code that couples the FENE‐P model to the equations of motion for an incompressible fluid. The simulations reveal that a pair of vortex rings traveling in opposite directions, with Reynolds numbers on the order of one, is generated from the sudden release of elastic stresses. Secondary vortical structures are also generated. In the concluding section of this work, we address the potential for vortex motions generated by elastic stresses to promote mixing in microflows, and we describe a possible experiment that may demonstrate this effect.

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“…As such, the elastic turbulence increases heat transfer by approximately 240 percent for the sucrose solution with a 150 ppm polymer concentration (relative to the Boger solution with ρc=0 ppm), when compared at the same disk rotational speed. 33,34…”

Section: Elastic Turbulence Investigationsmentioning

confidence: 99%

Propulsion Research and Academic Programs at the University of Alabama in Huntsville - 2018

Frederick

Ligrani

Thomas

2018

2018 Joint Propulsion Conference

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The UAH Propulsion Research Center (PRC) is beginning its 26 th year at the University of Alabama in Huntsville (UAH). The mission of the Propulsion Research Center is to provide an environment that connects the academic research community with the needs and concerns of the propulsion community while promoting an interdisciplinary approach to solving propulsion problems. This paper describes highlights from the research and academic programs associated with the center over the past eighteen months. Academic highlights include the offering of new graduate courses in liquid rocket engineering and solid rocket combustion instability. Research highlights include a new supersonic wind tunnel capability and a new program in nuclear thermal propulsion systems engineering. In the 2016 fiscal year, total research expenditures rose to $1.563 million and four Ph.D., eleven master's students, and numerous undergraduate students obtained degrees in conjunction with the center. The center continues to be a resource for both fundamental and applied research as well as a significant contributor to workforce development in the propulsion and energy field.

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Heat Transfer Enhancements from Elastic Turbulence Using Sucrose-Based Polymer Solutions

Cited by 17 publications

References 20 publications

Pore‐Scale Flow Characterization of Polymer Solutions in Microfluidic Porous Media

Pore‐Scale Flow Characterization of Polymer Solutions in Microfluidic Porous Media

Vortex generation in a finitely extensible nonlinear elastic Peterlin fluid initially at rest

Propulsion Research and Academic Programs at the University of Alabama in Huntsville - 2018

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