Experimental Investigation of Mixing in a T-Channel for Asymmetric Inlet Conditions

2012 ◽  
Author(s):  
Manjunath Basavarajappa ◽  
John Elsnab ◽  
Susan Thomas ◽  
Timothy A. Ameel
Keyword(s):  
Experimental Investigation ◽  
Volumetric Flow Rate ◽  
Flow Regimes ◽  
Laser Induced Fluorescence ◽  
Flow Conditions ◽  
Inlet Channel ◽  
Outlet Channel ◽  
Channel Geometry ◽  
Planar Laser ◽  
Inlet Conditions

An experimental investigation of water flow in a rectangular T-channel with inner dimensions of 20 × 20 mm (inlet channel) and 20 × 40 mm (outlet mixing channel) has been conducted. The inlet Reynolds number Re, based on inlet hydraulic diameter, ranged from Re1 = 90 to 775. Inlet flow conditions were asymmetric, and inlet Re ratios of Re1/Re2 = 1.24, 1.65 and 2.45 were obtained by varying volumetric flow rate. Dynamical conditions and T-channel geometry are directly applicable to microscale mixing. Planar laser induced fluorescence (LIF) was used to characterize flow regimes and behaviors, including periodicity, in the inlet and outlet channels. Two distinct flow regimes were identified and characterized for asymmetric inlet Re. For low inlet Re, Re1 ≤ 150, and all Re1/Re2, flows were steady. For higher Re and all Re1/Re2, a jet flow regime, characterized by two counter rotating vortices and increasingly turbulent at higher Re dominated the flow in the junction. Qualitative mixing characteristics for all flow regimes, based on LIF visualizations in the outlet channel, are also presented.

Experimental Investigation of Degree of Premixing on Isothermal Air-Water Two-Phase Flow Through Minichannel

2014 ◽  
Author(s):  
Hemant B. Mehta ◽  
Jyotirmay Banerjee
Keyword(s):  
Experimental Investigation ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Major Effect ◽  
Phase Flow ◽  
Inlet Channel ◽  
Two Phase ◽  
Channel Geometry ◽  
Flow Through ◽  
Isothermal Gas

The study on the effect of degree of premixing on isothermal gas-liquid two-phase flow pattern and flow pattern maps in microscale channels is inadequate. The present paper discusses the experimental investigation on air-water two-phase flow through 2.15 mm horizontal circular minichannel. Two type of inlet channel geometry, T-junction (TJ) and Y-junction (YJ), are considered. Six different flow patterns are observed and flow pattern maps are developed. The developed flow pattern maps for TJ and YJ channels are compared with the maps available in the literature. The surface tension dominated region is found to have major effect of inlet channel geometry. The results obtained for minichannel can be guidelines to analyze and design diverse two-phase microfluidic applications.

Experimental Investigation of Degree of Premixing on Isothermal Air-Water Two-Phase Flow Through Minichannel

2013 ◽  
Author(s):  
Hemant B. Mehta ◽  
Jyotirmay Banerjee ◽  
Jukesh A. Dodiya ◽  
Sanket Solanki
Keyword(s):  
Experimental Investigation ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Major Effect ◽  
Phase Flow ◽  
Inlet Channel ◽  
Two Phase ◽  
Channel Geometry ◽  
Flow Through ◽  
Isothermal Gas

The study on the effect of degree of premixing on isothermal gas-liquid two-phase flow pattern and flow pattern maps in microscale channels is inadequate. The present paper discusses the experimental investigation on air-water two-phase flow through 2.25 mm horizontal circular minichannel. Two type of inlet channel geometry, T-junction (TJ) and Y-junction (YJ), are considered. Six different flow patterns are observed and flow pattern maps are developed. The developed flow pattern maps for TJ and YJ channels are compared with the maps available in the literature. The surface tension dominated region is found to have major effect of inlet channel geometry. The results obtained for minichannel can be guidelines to analyze and design diverse two-phase microfluidic applications.

PARTICLE-FREE EXTRACTION BY USING MICROCHANNEL STRUCTURES

2012 ◽  
Vol 19 ◽  
pp. 237-241
Author(s):  
TZONG-SHYNG LEU ◽  
CHING-YI PAI
Keyword(s):  
Reynolds Number ◽  
Flow Rate ◽  
Experimental Studies ◽  
Volumetric Flow Rate ◽  
Reynolds Numbers ◽  
Free Fluid ◽  
Microfluidic Chips ◽  
Inlet Channel ◽  
Outlet Channel ◽  
Inlet Flow Rate

Modern separation methods of particles are usually prepared by large equipments. In this study, microfluidic chips with backward-facing-step (BFS) microchannel structures and centrifugal force are used to extract particle-free fluid from physical samples at the branch. Numerical simulation and experimental studies were performed to investigate the effects of inlet Reynolds number ( Re 0), as well as the particle-free fluid outlet Reynolds number ( Re 1), on the minimum radius of particles (R) that can be excluded from the particle-free fluid outlet channel. The fraction of the volumetric flow rate of particle-free extraction α (=extraction flow rate/inlet flow rate) was also obtained to evaluate the efficiency of particle-free extraction. Based on the numerical and experimental results, it is found that the design with 90° elbow inlet channel has a better performance than straight inlet channel. In this experiment, 1.0 μm radius of particles can be successfully separated from the fluid, and the volumetric fraction of the extraction flow rate was approximately 1.8% when inlet and outlet Reynolds numbers are 90 and 3.0 respectively.

Quantification of mixing of oxygen and iodine in Chemical Oxygen Iodine Lasers using planar laser induced fluorescence

2000 ◽  
Author(s):  
T. Muruganandam ◽  
Srihari Lakshmi ◽  
A. Ramesh ◽  
S. Viswamurthy ◽  
R. Sujith ◽  
...  
Keyword(s):  
Laser Induced Fluorescence ◽  
Planar Laser Induced Fluorescence ◽  
Planar Laser
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