Modeling Acoustic Effects on Shear-Coaxial Jet Flow Utilizing Molecular Dynamic Simulation

The purpose of this research is to determine if acoustical effects on a coaxial shear injection jet flow can be modeled utilizing molecular dynamic simulation. Molecular dynamic simulations model flows as a group of interacting particles. The flow in this research was simulated using nitrogen molecules. The initial task involved achieving effective geometry for a simulated coaxial jet. The coaxial jet geometry was driven by the desire for simulations to operate in the continuum regime, which requires very low Knudsen numbers. Three outer to inner jet ratios of 0.0, 1.0, and 6.0 were examined with the inner jet velocity maintained constant at 50 m/s. Velocity profiles in the injector need to be controlled in order to validate the continuum flow. Acoustic interference is introduced into the simulation, and mixing and density profiles provide valuable information into the how the flow is affected by the acoustic interference. Radial density profiles also provide information about the shape of the jet with and without acoustic interference as it exits the injector. The effects of acoustic interference for most cases showed good agreement with previous experimental data. Results showed good validation of the simulation and warrants more in-depth study.