Graduation Year


Document Type




Degree Name

MS in Mechanical Engineering (M.S.M.E.)

Degree Granting Department


Major Professor

Rasim Guldiken, Ph.D.

Committee Member

David Muprhy, Ph.D.

Committee Member

Andres Tejada-Martinez, Ph.D.


Fluid Mechanics, Microfluidics, Mixing efficiency


Current experimental and simulation fluid mixing studies aim to increase mixing efficiency and incorporate various measurement methods to quantify mixing. In this thesis, comprehensive simulation and experimental studies were carried out to investigate the effects of an orifice plate on mixing. Mixing efficiency is measured through the correlation of volume fraction to color light reflectivity, as dyes were introduced to the fluids being mixed. Volume fractions close to 0.5 indicate high mixing performance, and the efficiency declines as volume fractions depart from 0.5. It was found that fluids in a small diameter tube do not mix due to the absence of eddies or swirling motions. Measurements were taken at regions away from the centerline of the tube and volume fractions of 0.85 and 0.91 were obtained.

Fluids have shown significant mixing performance when passing through the orifice plate. The regions where samples were taken after the obstruction were maintained and volume fractions of 0.59 and 0.45 were recorded. Simulation results were also analyzed and compared against experimental results. The simulation was then used to investigate vorticity effects on mixing in and around the plate. Results show that higher vorticity occurs in the plate and that is where higher mixing performance is observed when volume fraction results are displayed. This indicates that an orifice plate is an effective passive mixing method to implement in a flow for wide variety of applications.