Papers by Keyword: Micro Channel

Abstract: A novel micromachining technology is investigated in this work. Precision machining of micrometer sizes can be achieved by a tool scraping on CNC machine. The knife for scraping with small knife nose with radius of fifty micrometer can scrape surfaces of designed function by path planning of CNC machine. To investigate performance, micro channels are scraped on workpieces by micro shaping. For tool path planning, feeding rate and scraping depth have significant effect on machining performance and depth-to-width ratio. Poly-methyl methacrylate (PMMA) and aluminum alloy are materials for scraping. From the results of experiments, aluminum alloy has better machining performance and smoother scraping surface than PMMA. Smaller scraping depth would induce better performance and size precision. For feeding rate, 800 mm/min is better for PMMA and 500 mm/min is better for aluminum alloy.

Abstract: This paper investigates the performance and characteristics of saw tooth shape micro channel in the theoretical level. If the conduct area of the nano fluid increases the heat transfer also increases. The performance curve has drawn Reynolds number against nusselt number, heat transfer co efficient. Pressure drop plays an important role in this device. If pressure drop is high the heat transfer increases. The result in this experiment shows clearly that the heat transfer is optimized.

Abstract: For indepth study on flow characteristics for fluid bypass obstacles in micro-channel, the Lattice Boltzmann Method (LBM) was used to simulate fluid flow over two circular cylinders in side-by-side arrangement of a micro-channel. The velocity distribution and recirculation zone length under different Reynolds numbers (Re = 0~100) and different spacing ratio (H/D= 0~2.0) were obtained. The results show that the pattern of flow and the size of recirculation zone in the micro-channel depend on the combined effect of Re and H/D.