Liquid jet in crossflow systems are often used as lightweight and efficient mechanisms of atomizing fuel prior to entertainment in the flame holder and combustion, making them integral components of liquid fueled engines. Unfortunately, such systems are susceptible to deviations in both trajectory and breakup rate, depending primarily on the Weber number and momentum flux ratio of the injected jet. In these studies, the effects of solid obstructions, called pintiles, on the variability of liquid jet in cross flow trajectory and breakup are investigated. Initial investigations looked at the impacts of broad geometric parameters on flow independence, using Mie scatter imaging and phase Doppler particle analysis. The results of that investigation yielded an optimal overarching geometry for pintiles. This knowledge was then refined by looking at specific face characteristics of the obstructions, primarily investigating face angle and concavity. Spray characteristics were spatially resolved using LIF/Mie particle sizing techniques, revealing that modest convex surfaces yielded the most consistent breakup characteristics across space, while simultaneously improving the average breakup distance of the liquid jet. Finally, this progression of pintile characteristics is investigated on the effects pintiles have on overarching flame properties, using C2*/CH* chemiluminescence ratios to determine spatially resolved equivalence ratio distributions across a wide range of Weber numbers and momentum flux ratios encompassing breakup regimes from the enhanced capillary modes through to shear breakup modes. Results from these studies demonstrate significant improvement of combustion properties from the introduction of the pintiles.


If this is your thesis or dissertation, and want to learn how to access it or for more information about readership statistics, contact us at STARS@ucf.edu

Graduation Date





Ahmed, Kareem


Doctor of Philosophy (Ph.D.)


College of Engineering and Computer Science


Mechanical and Aerospace Engineering

Degree Program

Aerospace Engineering


CFE0009502; DP0027504





Release Date


Length of Campus-only Access

5 years

Access Status

Doctoral Dissertation (Campus-only Access)

Restricted to the UCF community until 5-15-2028; it will then be open access.