This project aims to investigate the high-speed forced flow associated with the underexpanded impinging jet (UIJ). This flow is a critical component of diverse processes ranging from pharmaceutical systems to novel manufacturing processes, to aerospace propulsion applications. It is our contention that the underexpanded impinging jet flow is an inherently forced flow. This forcing is acoustic in nature, primarily driven via a feedback process that has its origin at the impingement surface. The nature of this “forced” flow is very poorly understood. This lack of understanding persists due to the fact that the typical “steady state” case (i.e. the only one readily amenable to observation), has its own inbuilt forcing mechanism, in the form of the aforementioned acoustic feedback process. This inherent self-forcing means that the underlying “natural” stability of the jet cannot be directly inferred from the mean state of this “forced” flow. The lack of fundamental understanding regarding the nature and stability characteristics of the UIJ makes prediction of these flows nearly impossible. Without predictive ability, dynamic control of the flow in its many diverse industrial applications is highly unreliable. High fidelity large eddy simulations (LES) to allow for an in-depth investigation into the nature and dynamical response characteristics of UIJ flows are performed. The datasets of large-eddy simulation of under-expanded supersonic impinging jets funded by the Australian Research Council are stored on this storage allocation
Funding
Impinging supersonic jets: stability and control - with application to cold spray