Enhanced surfaces such as microfins can be an effective way to remove a large amount of heat from a small area. The design of microfin enhanced surfaces affects the heat transfer and pressure drops which are the two key factors of efficiency. Normally, researchers analyze the macro relationship between the efficiency of heat transfer and micro-fins to obtain correlations, which reveals how newly designed geometries, i.e., width, height, shape, angle, etc., affect the heat transfer and pressure drops but are not predictive for new geometries because the detailed flow physics are not identified [1]. Very few studies have explored the link between flow characteristics and heat transfer/pressure drops both experimentally and numerically. The detailed time-resolved characteristics of flow near the wall around the micro-fins are not well understood because experimental and numerical data are limited.The current study proposes a numerical model with ANSYS Fluent to collect and analyze the relationships between the flow patterns and heat transfer/pressure drops on a microfin enhanced surface. The fin structure was created by Webb et al. [2] and was manufactured on the top of the copper block through micro-machining. We utilized a large eddy simulation (LES) with a localized dynamic kinetic energy subgrid-scale model (LDKM) to predict the flow patterns. The authors were aware of very few systematic studies in the literature on implementing LES in wall-bounded flows with heat transfer/pressure drops on microfin enhanced surfaces. Furthermore, the accuracy of the numerical model was verified by experimental results. The authors used a commercial, telescopic, particle image velocimetry (PIV) system to capture flow characteristics for validation.Flow visualization videos are good tools to illustrate detailed time-resolved flow patterns. It is convenient to reveal the transient relationships between flow patterns and heat transfer/pressure drops. The flow visualization videos with high quality help the researchers to figure out the physics and mechanics driving the performance of the micro-finned surfaces.Reference[1] Li P, Campbell M, Zhang N, et al. Relationship between turbulent structures and heat transfer in microfin enhanced surfaces using large eddy simulations and particle image velocimetry[J]. International Journal of Heat and Mass Transfer, 2019, 136: 1282-1298.[2] Webb R L, Narayanamurthy R, Thors P. Heat transfer and friction characteristics of internal helical-rib roughness[J]. J. Heat Transfer, 2000, 122(1): 134-142.

Flow Pattern on Microfin Enhanced Surfaces (Videos)

Paper Proceedings: https://asmedigitalcollection.asme.org/FEDSM/FEDSM2021/volume/85284

ASME 2021 Fluids Engineering Division Summer Meeting (FEDSM2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.