Laminar Near Wake of Hypersonic Blunt Bodies
Abstract
A detailed analysis of the mechanisms of the hypersonic laminar near-wake is presented. Simulations of the compressible Navier-Stokes equations in two dimensions for various geometries (a cylinder, sphere, and a truncated aft-body cylinder) at a range of Mach (6<M<10) and Reynolds (8x10^3<Re<10^5) numbers have been simulated. Using the simulation results for supporting discussion and analysis, a new theoretical framework for the hypersonic laminar near-wake was developed and is presented here. A semi-empirical relation is derived which can be used to estimate the local characteristic Reynolds number of the wake. Semi-empirical relations are developed and presented for pressure minimum location, separation location, separation length, and viscous-inviscid interaction parameters. The dependence of these parameters on free-stream properties such as Mach and Reynolds number are highlighted. Viscous-inviscid interaction theories are derived and presented for the lip and reattachment shock wave formation processes. As well, a theory is presented that allows the rear stagnation point pressure distribution to estimate the wake centerline Mach number and the effective diameter of the reversed flow jet. The developed sub-mechanisms are then combined into a new overall theoretical framework for the laminar near-wake. Using scaling arguments, the role of each sub mechanism as flow conditions change is discussed. Using the presented theoretical framework and empirical relations, a detailed review and disambiguation of results found in the literature is presented.
Description
Keywords
Engineering--Aerospace, Engineering--Mechanical
Citation
Hinman, W. S. (2017). Laminar Near Wake of Hypersonic Blunt Bodies (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26716