Mechanical Characterisation and Analysis of a Passive Micro Heat Exchanger

Abstract

<jats:p>Heat exchangers are widely used in many mechanical, electronic, and bioengineering applications at macro and microscale. Among these, the use of heat exchangers consisting of a single fluid passing through a set of geometries at different temperatures and two flows in T-shape channels have been extensively studied. However, the application of heat exchangers for thermal mixing over a geometry leading to vortex shedding has not been investigated. This numerical work aims to analyse and characterise a heat exchanger for microscale application, which consists of two laminar fluids at different temperature that impinge orthogonally onto a rectangular structure and generate vortex shedding mechanics that enhance thermal mixing. This work is novel in various aspects. This is the first work of its kind on heat transfer between two fluids (same fluid, different temperature) enhanced by vortex shedding mechanics. Additionally, this research fully characterise the underlying vortex mechanics by accounting all geometry and flow regime parameters (longitudinal aspect ratio, blockage ratio and Reynolds number), opposite to the existing works in the literature, which usually vary and analyse blockage ratio or longitudinal aspect ratio only. A relevant advantage of this heat exchanger is that represents a low-Reynolds passive device, not requiring additional energy nor moving elements to enhance thermal mixing. This allows its use especially at microscale, for instance in biomedical/biomechanical and microelectronic applications.</jats:p>

A Review on Additive Manufacturing of Micromixing Devices

“…Nowadays, micromixers, as well as other fluidic microdevices, are used for different potential applications, which may or not be limited to particle concentration detection with an active dielectric mixer [34], glucose concentration detection with a passive circular mixer [35], or for dual quantitative detection of analytes with a passive Tesla mixer [36]. Applications more related to mechanical engineering may also include the mechanical characterisation and analysis of passive micro heat exchangers [37], heat transfer calculations and pressure drop measurements with a serpentine mixer [38], mixing efficiency and pressure drop for passive micromixer based on the topology optimization method [39], and plasma mixing analysis with a passive square-wave mixer [40]. These are microscale devices manufactured for the mixing of two fluid materials, usually achieved in microchannels with external turbulence and/or by the use of special microstructures [41].…”

Performance Evaluation of Micro Automatic Pressure Measurement Sensor for Enhanced Accuracy

“…The design is divided into two parts: theoretical design and application testing. It includes several modules, such as sensitive diaphragm design, conversion element design, signal conversion circuit design, sensor interface circuit design and working program design [6,7].…”

Editorial for the Special Issue on Analysis, Design and Fabrication of Micromixers

“…The current special issue includes 12 research papers [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. The topics of the papers are focused on design of micromixers [ 2 , 3 , 4 , 5 , 6 , 7 , 9 , 12 , 13 ], fabrication [ 8 , 9 , 12 ], and analysis [ 11 ].…”

“…Different methods have been applied to the analysis of mixing. Most of the works used only computational fluid dynamics (CFD) for the analysis [ 2 , 3 , 4 , 5 , 6 , 10 , 13 ]. However, some of the works employed experimental analysis [ 8 , 9 ] or both experimental and CFD analyses [ 7 , 12 ].…”

“…They suggested the physical foundation for the electromagnetic coupling in the micromixer, and derived a correlation between the mechanical velocity and electrical driving point impedance. Exceptionally, Granados-Ortiz and Ortega-Casanova [ 10 ] analyzed the thermal mixing between two parallel laminar flows with different temperatures in a simple 2D channel with an obstacle located at the center. They performed unsteady 2D Navier-Stokes analysis to analyze the mixing caused by the vortex shedding behind the obstacle.…”