Drag and Heat Transfer of Double-Disk Spiked Blunt Body at Mach 5.7

Abstract

This study focuses on exploring the possibility of addressing aerodynamic drag and heat transfer on a blunt body by placing a modified aerospike at the nose of a high-speed vehicle. Designed spiked configurations mounted over a blunt body are termed a double spike. This study examines the overall performance of these spikes in terms of drag and heat transfer. Experiments are carried out in a shock-tunnel facility, capable of simulating the enthalpy effect at high Mach number. Drag measurements over the spiked blunt body were done using an internally mountable accelerometer balance system at a freestream Mach number of 5.7 and enthalpy of 1.1 MJ/kg. Simulations using the three-dimensional finite volume-based solver High Resolution Flow Solver on Unstructured meshes lead to the selection of double-spike configurations for experimentation. Interestingly, schlieren and simulations observed the flow phenomenon modifications by the double spike with the hemispherical cap/disk at the midsection of the spike. For a specific configuration of the midspike, this study indicates that the shear layer detached by the spike tip would interact with the midspike compared to the single-spike configurations. The results show that these double-spike configurations reduce the localized heat transfer over a blunt-body surface without appreciable change in the drag. Double-spike configurations with varying midsection spike geometry, locations, and thickness of the spike are investigated. The contributions of the spike length, cap diameter, and midspike shape on overall drag and localized heat transfer were analyzed.