MMAE Seminar - Dr. Jin Wang - X-ray Vision: Probing the Dynamics of High-Pressure Fuel Injection Processes

Armour College of Engineering's Mechanical, Materials & Aerospace Engineering Department will welcome Dr. Jin Wang, Argonne National Laboratory, on Wednesday, February 8th, to present his lecture, X-ray Vision: Probing the Dynamics of High-Pressure Fuel Injection Processes.

Abstract

The advent of the third-generation synchrotron x-ray light sources has stimulated extensive engineering research activities far beyond conventional non-destructive testing. Brilliant, intense, and penetrating x-rays have provided the visions to reveal structures and dynamics in engineering materials in states far from equilibrium with high spatial and temporal resolution of nanometers and nanoseconds. Imagine that you can watch the structural evolution of industrial materials during dynamic compression or monitor phase transitions in a single nanofiber during electrospinning with x-ray vision? In fluid dynamics research, turbulence and multiphase flow remain among the most demanding areas presenting both experimental and computational challenges. A familiar example is in understanding the dynamics of high-pressure and high-speed fuel sprays leading to combustion. The evolution of fuel spray through liquid breakup plays a defining role in controlling the efficacy of ignition and the uniformity of combustion, and hence in determining both the combustion efficiency and the formation of emissions. The challenge is to obtain a full spatiotemporal description of the spray from its birth to ignition and to describe it fully by utilizing hydrodynamic computational models. Fuel sprays, often traveling at a supersonic speed, are difficult to visualize with conventional optical imaging and scattering methods, particularly in the region close to the nozzle. Synchrotron-based ultrafast x-ray imaging techniques are now proven to be effective to provide detailed information on the breakup process of high-pressure sprays, fuel distribution and dynamics close to the nozzle in regimes beyond the capillary wave-controlled low-velocity domain.