A Study on the Flow Characteristics of Micro-Elbows

In this study, we modeled two micro-elbows with dimensions with 20×1×5810 μm³ and 90° turn at the channel centre. In case of the right angle elbow, the channel turns sharply at a right angle, and in case of the round elbow, the channel turns smoothly 60 μm radius of curvature. In order to investigate flow characteristics, numerical analyses are carried out with pressure driven condition and argon gas. Mass flow rate and pressure distribution of micro-elbows are calculated. Due to the low Reynolds number and Knudsen number Kn = 0.06, we used laminar and compressible Navier-Stokes equation and slip boundary conditions. Although the turn angle of micro-elbows is the same, 90°, mass flow rate is not the same. Mass flow rate of the right angle elbow is lower than that of the round elbow. Besides, in case of the same flow rate, the pressure drop of right angle elbow is larger than that of round elbow. As the mass flow rate decreases, the pressure drop of micro-elbows is increased. Results also show that in a right angle channel, small separation is came into existence in the sharp corner bend of inner wall.