Investigation of Non-Newtonian Fluid Behavior and Coefficient of Friction in Water Hammer Phenomena

An unstable flow of non-Newtonian fluid, with friction in a pipe is studied, describing the water hammer phenomenon. The equations of the problem are given, then solved by a numerical approach. The non-Newtonian behavior of the fluid, as well as the effect of the coefficient of friction which represents an additional mechanism of energy dissipation are investigated. The 1D and 2D problem is used simultaneously, based on the Runge-kutta method for the descritization in time, Finite differences, Characteristics for the descritization in space. The results of this article show by verifying with experience that these methods used, in addition to being simple, are also effective and give reasonable results.

Biomaterials for microfluidic technology

Micro/nanomaterial-based drug and cell delivery systems play an important role in biomedical fields for their injectability and targeting. Microfluidics is a rapidly developing technology and has become a robust tool for preparing biomaterial micro/nanocarriers with precise structural control and high reproducibility. By flexibly designing microfluidic channels and manipulating fluid behavior, various forms of biomaterial carriers can be fabricated using microfluidics, including microspheres, nanoparticles and microfibers. In this review, recent advances in biomaterials for designing functional microfluidic vehicles are summarized. We introduce the application of natural materials such as polysaccharides and proteins as well as synthetic polymers in the production of microfluidic carriers. How the material properties determine the manufacture of carriers and the type of cargoes to be encapsulated is highlighted. Furthermore, the current limitations of microfluidic biomaterial carriers and perspectives on its future developments is presented.

Print-and-Play Fabrication

In recent years, it has become increasingly accessible to create interactive applications on screen-based devices. Contrary to this ease, and despite their numerous benefits, creating tangible interactive devices is a task reserved for experts, requiring extensive knowledge on electronics, and manual assemblies. While digital fabrication equipment holds promise to alleviate this situation, the majority of research exploring this avenue still present significant barriers for non-experts, and other-domain experts to construct tangible devices, often requiring assembly of electronic circuits and printed parts, prohibitive fabrication pipelines, or intricate calibration of machine learning models. This thesis introduces Print-and-Play Fabrication: a digital fabrication paradigm where tangible interactive devices are printed, rather than assembled. By embedding interior structures inside three-dimensional models that leverage distinct properties of fluid behavior, this thesis presents a variety of techniques to construct tangible devices that can sense, process, and respond to user’s interactions without requiring assembly of parts, circuits, or calibration of machine learning models. Chapter 2 provides an overview of the fabrication of tangible devices literature through the lens of Print-and-Play Fabrication. This chapter highlights the post-print activities required to enable each of the efforts in the literature, and reflects on the status of the field. Chapters 3 and 4 introduce two novel techniques for constructing tangible devices that can sense user’s interactions. AirTouch uses basic principles of fluid behavior to enable the construction of touch-sensing devices, capable of detecting interactions in up to 12 locations, with an accuracy of up to 98%. Blowhole builds on this concept by employing principles of acoustic resonance to construct tangible devices that can detect where they are gently blown on. Blowhole-enabled devices can enable up to seven interactive locations, with an accuracy of up to 98%. Conversely, in Chapter 6 I introduce a technique to encapsulate logic computation into 3D-printed objects. Inspired by concepts from the Cold War era, I embed structures capable of representing basic logic operations using interacting jets of air into three-dimensional models. AirLogic takes the form of a toolkit, enabling non-expert designers to add a variety of input, logic processing, and output mechanisms to three-dimensional models. Continuing, Chapter 5 describes a toolkit for fabricating objects capable of changing their physical shape using pneumatic actuation. MorpheesPlug introduces a design environment, a set of pneumatically actuated widgets, and a control module that, in tandem, enable non[1]experts to construct devices capable of changing their physical shape in order to provide output. Last, I conclude with reflections on the status of Print-and-Play Fabrication, and possible directions for future work.

Development of a control system to maintain steady transition boiling

Steady transition boiling offers opportunities to observe fluid behavior and to measure transient and local heat flux as the surface dries and wets. This report discusses temperature control in transition boiling. Each component in the control system is either measured or estimated, and the controller parameters are determined along with the optimum depth of the temperature feedback point. Experiments are performed to verify the theoretical stability limit.

Designing Complex Fluids

Taking a small step away from Newtonian fluid behavior creates an explosion in the range of possibilities. Non-Newtonian fluid properties can achieve diverse flow objectives, but the complexity introduces challenges. We survey useful rheological complexity along with organizing principles and design methods as we consider the following questions: How can non-Newtonian properties be useful? What properties are needed? How can we get those properties? Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Competition Between Cell-Cell and Cell-Substrate Adhesion Determines Epithelial Monolayer Architecture in Culture

Organ surfaces are lined by epithelial monolayers - sheets of cells that are one-cell thick. This architecture underlies tissue function, and its loss is associated with disease, including cancer. Studies of in-plane epithelial cell behaviors show that a developing epithelium behaves as a fluid in respect to the tissue plane, and can therefore readily adapt to varying mechanical influences during morphogenesis. We asked the question of how monolayer architecture is achieved, and whether it demonstrates the same fluid behavior. To address this problem, we cultured MDCK (Madin-Darby Canine Kidney) cell layers at different densities and timepoints and analyzed their architectures using a novel tool, Automated Layer Analysis (ALAn), which we introduce here. Our experimental and theoretical results lead us to propose that epithelial monolayer architecture is governed by a balance of counteracting forces due to cell-cell and cell-substrate adhesion, and that this balance is influenced by cell density. MDCK cells do not undergo obvious rearrangement along the apical-basal axis; instead, cells that do not contact the substrate aggregate on top of the monolayer. Our findings therefore imply that monolayered architecture is under more rigid control than planar tissue shape in epithelia.

An Adaptive Sequential Fully Implicit Domain-Decomposition Solver

Summary Modern reservoir simulation must handle complex compositional fluid behavior, orders-of-magnitude variations in rock properties, and large velocity contrasts. We investigate how one can use nonlinear domain-decomposition preconditioning to combine sequential and fully implicit (FI) solution strategies to devise robust and highly efficient nonlinear solvers. A full simulation model can be split into smaller subdomains that each can be solved independently, treating variables in all other subdomains as fixed. In subdomains with weaker coupling between flow and transport, we use a sequential fully implicit (SFI) solution strategy, whereas regions with stronger coupling are solved with an FI method. Convergence to the FI solution is ensured by a global update that efficiently resolves long-range interactions across subdomains. The result is a solution strategy that combines the efficiency of SFI and its ability to use specialized solvers for flow and transport with the robustness and correctness of FI. We demonstrate the efficacy of the proposed method through a range of test cases, including both contrived setups to test nonlinear solver performance and realistic field models with complex geology and fluid physics. For each case, we compare the results with those obtained using standard FI and SFI solvers. This paper is published as part of the 2021 Reservoir Simulation Conference Special Issue.