Session: K8-03: FUNDAMENTALS OF MULTI-PHYSICS TRANSPORT AND MACHINE LEARNING

Paper Number: 132241

132241 - Choked Gas and Liquid Carbon Dioxide Flow Through Microchannels With Parallel Multi Orifices 

Abstract: 

Carbon dioxide (CO2) has an excellent capability for cooling applications due to its exceptional thermophysical properties near the pseudocritical condition. However, literature pertinent to these conditions is scarce, and as a result, predicting the fluid flow in equipment and flow restriction elements near the critical condition, is challenging. When CO2 flow passes through a constriction and experiences a large pressure drop, it can become sonic. In this state, the flow rate is independent of the downstream conditions. In this study, we investigate the depressurization effect on the mass flow rate through channels with multiple micro constriction elements. Two silicon-based microfluidic devices consisting of arrays of microchannels (micro-orifices), are studied. A silicon wafer is etched through a DRIE process to create the fluidic ports. Then, the silicon wafer is anodically bonded to a 5-mm-thick polished Pyrex to seal the device from the top. These two devices consist of microchannel arrays with width of 50 μm (20 orifices) and 100 μm (10 orifices), and a height of 100 μm (i.e., the height-to-width aspect ratios (H/W) of these devices are 2 and 1, respectively). They include rectangular inlet and outlet for uniform flow distribution through array of microchannels. A close-loop experimental setup was built to provide control and measurement of pressure and temperature at the inlet and outlet. Inlet pressure ranged from 5.5 to 8.5 MPa, and outlet pressure ranged from 0.1 to 5.5 MPa. Mass flow rate and density are controlled and measured by a Coriolis flow controller at the inlet. Measurements were complemented by visualization through a high-speed camera and a microscope.

Presenting Author: Soroush Niazi University of Central Florida

Presenting Author Biography: Soroush Niazi received his B.Sc. degree in Mechanical Engineering from Shahid Beheshti University, Tehran, Iran, in 2018, and his M.Sc. degree in Mechatronics Engineering from Sabanci University, Istanbul, Turkey, in 2021, with a focus on enhancing the performance of phase change cooling systems. He is currently pursuing his Ph.D. degree in the Mechanical Engineering Department at the University of Central Florida. He is investigating heat transfer mechanisms of supercritical CO2 near the critical point and cavitating flow characteristics inside microchannels.

Authors:

Soroush Niazi University of Central Florida
Yoav Peles University of Central Florida