Fluid flow characteristics of a multi-scale fluidic network

Abstract

This paper presents an original study on the fluid flow characteristics of a multi-scale fluidic network consisting of a number of elementary ladders. Computational Fluid Dynamics (CFD) simulations were performed to characterize local fluid flow patterns and flow distribution properties in such a complex geometry. In parallel, flow visualizations using fast camera and tracers were carried out in a transparent prototype. A special effort was made to improve the flow distribution uniformity among the 90 parallel mini-channels by inserting the geometrically optimized perforated baffles. The global pressure losses of the multi-scale network with or without baffles were also measured experimentally so as to be compared with the numerical results.For the multi-scale fluid network, non-uniform flow distribution was observed even under very low flow-rate conditions (e.g., mean Rech=10). For higher flow-rate conditions, significant flow nonuniformity seems inevitable. The insertion of optimized perforated baffles could provide a remarkable improvement on flow distribution uniformity, even under high flow-rate conditions (mean Rech up to 2000). Good agreements between numerical and experimental results are observed.

Thermal performances of a multi-scale fluidic network

“…The studied geometry of multi-scale network is exactly the same as that shown in Fig. 1 of [38], with 90 mini-channels in total. Ten identical mini-channels are arranged in parallel and linked together by a distributor and a collector in perpendicular position.…”

“…Each mini-channel has a square cross-section of 1 mm × 1 mm (hydraulic diameter D h = 1 mm; aspect ratio AR = 1) and a channel length of 50 mm. Detailed dimensions for the connecting distributors and collectors may be found in Table 1 of [38].…”

“…The perforated baffles are basically in the form of thin rectangular shape slices made of PMMA (1 mm in thickness). More details on the optimization of orifice sizes and their insertions may be found in our previous hydrodynamic study [38]. An uncertainty analysis was performed following the method of Moffat [41].…”

“…In our previous work [38], the fluid flow characteristics of a multiscale fluidic network consisting of 9 elementary Z-ladders and 90 parallel mini-channels have been investigated and discussed. A special effort was made to improve the flow distribution uniformity by [39,40], which has been proved to be really cost-effective.…”

“…A special effort was made to improve the flow distribution uniformity by [39,40], which has been proved to be really cost-effective. As the following of [38], this paper presents the thermal performances of such multi-scale structured fluidic network so as to illustrate the benefits of multi-scale structuration concept. Since an analytical description of the flow remains elusive due to the non-developed flow patterns in such a complex geometry, a numerical study is performed to provide an insight of the thermal-fluid characteristics.…”