Thermal mixing of two miscible fluids in a T-shaped microchannel

Abstract

In this paper, thermal mixing characteristics of two miscible fluids in a T-shaped microchannel are investigated theoretically, experimentally, and numerically. Thermal mixing processes in a T-shaped microchannel are divided into two zones, consisting of a T-junction and a mixing channel. An analytical two-dimensional model was first built to describe the heat transfer processes in the mixing channel.In the experiments, de-ionized water was employed as the working fluid. Laser induced fluorescence method was used to measure the fluid temperature field in the microchannel. Different combinations of flow rate ratios were studied to investigate the thermal mixing characteristics in the microchannel. At the T-junction, thermal diffusion is found to be dominant in this area due to the striation in the temperature contours. In the mixing channel, heat transfer processes are found to be controlled by thermal diffusion and convection. Measured temperature profiles at the T-junction and mixing channel are compared with analytical model and numerical simulation, respectively.

Investigation of acoustic streaming patterns around oscillating sharp edges

“…An important requirement for these systems is the ability to rapidly and efficiently mix small amounts of samples at microscales 15,66 . Various techniques have been utilized to enable rapid mixing in microfluidic devices including chaotic advection 13,14,26,33,40,62 , hydrodynamic focusing 45,51 , electrokinetically driven mixing 16,23,32,48,60 , 3D combinatorial bubble-based mixing 38,47 , and thermally- 63,69 as well as optically-induced 25 mixing. Recently, acoustic-based mixers 39,43,52,59,64 have generated significant interest because of their non-invasive nature.…”

Versatile Microfluidic Platforms Enabled by Novel Magnetorheological Elastomer Microactuators

“…5C-E. The difference in size distribution could due to the fact that higher concentration of glucose (pumped by Pump 2) resulted in a higher reaction rate that consequently increased the supersaturation, 20 higher supersaturation normally results in smaller primary particles and the presence of PVP prevents aggregation. [32] In addition to using multiple micropumps for driving liquids in parallel, we also demonstrated pumping liquids in series using cascaded pump configurations, as shown in Supporting Information S5.…”

“…[17] A passive approach for obtaining mixing is to induce secondary flows by altering the structures or geometries of the flow channels. [18] On the other hand, active mixing can be achieved using acoustic, [19] thermal, [20] CEW, [21] and electrokinetic [22] effects. Similar to the problems associated with micropumps, current micromixers often require bulky peripherals to drive them, or have limited liquids that can be mixed.…”

Fluid manipulation on the micro‐scale: Basics of fluid behavior in microfluidics

“…Xu et al. analyzed mixing of two solutions, one heated and one cold, in a T‐shaped micro‐mixer. Using temperature‐dependent fluorescence of Rhodamine B, two heat transfer zones could be differentiated.…”

“…In one example a PCR microfluidic chamber designed by Kim et al [45], involved alternating heating of two channel segments to enhance mixing. Xu et al [46] analyzed mixing of two solutions, one heated and one cold, in a T-shaped micro-mixer. Using temperaturedependent fluorescence of Rhodamine B, two heat transfer zones could be differentiated.…”