UC Researchers Go with the Flow

A paper written by faculty and researchers of the School of Aerospace Systems has been selected to be presented at the 58th ASME International Gas Turbine Expo. The paper, “Response of Liquid Jet to Modulated Crossflow,” will be presented at the conference on June 3-7, 2013, in San Antonio, Texas.

Post-doctoral scholar Jinkwan Song serves as the first author and primary contributor on a team of UC researchers including co-authors graduate student Chandrasekar Ramasubramanian and Ohio Research Scholar Jongguen Lee.

"Jet in crossflow" is a canonical concept in fluid mechanics. “Jet in crossflow helps us investigate and analyze the effects of turbulent mixing and combustion,” said Ramasubramanian.  “Its significance lies in engineering technologies such as air-breathing propulsion systems and dilution holes in combustors.” 

The research primarily focuses on observing and identifying scientific phenomena occurring during the course of the experiment and analyzing the effect of the modulated crossflow in terms of an STF (spray transfer function).

According to Ramasubramanian, the performance of air-breathing jet engines, invented as early as the 1930s, continues to grow at an exponential pace with improvements in efficiency and performance characteristics. “They use the system of transverse injection of liquid fuel into airflow making the liquid jet bend towards the leeward direction.  The liquid jet then breaks up due to the presence of aerodynamic acceleration on the windward surface,” Ramasubramanian explains. “Our research characterizes this spray pattern.”

At Lee’s direction, the researchers wanted to pursue this fundamental research area from a modern and practical standpoint of modulated crossflow. “The uniqueness and sophistication involved in our experiment involved a modulation in the crossflow with the help of a modulating device (siren) which can be used to enforce a periodic modulation of cross air flow rate,” said Ramasubramanian.

The key findings of the paper indicate that the atomization of droplets is enhanced under modulated crossflow.  “This was further confirmed with the help of advanced laser based technologies such as Phase Doppler Particle Anemometry and Particle Image Velocimetry,” said Ramasubramanian.

According to Ramasubramanian, the results of this research may prove to be very useful. “An analysis of how an oscillating crossflow affects the fuel injection process in ramjet, scramjet and turbojet engines may provide us with a method to determine, control and/or suppress the growth of instabilities occurring during the combustion process.”

About the Conference

The ASME International Gas Turbine Expo is recognized as “the must attend event” for turbo-machinery professionals because of its well-earned reputation for bringing together the best and brightest experts from around the world to share the latest in turbine technology, research, development, and applications in the areas of gas turbines, steam turbines, wind turbines, fans & blowers, solar brayton & rankine cycle and supercritical CO2.

The three-day exhibition attracts industry's leading professionals and decision makers, whose innovation and expertise are helping to shape the future of the turbo-machinery industry.