Numerical investigation of the effect of disk position on the aerodynamic heating and drag of a spiked blunt body in hypersonic flow

Abstract

Detailed numerical simulations have been carried out on a spiked blunt body with multiple hemispherical disks using a commercial CFD code in order to investigate their effectiveness in reducing the aerodynamic drag and heating. The base configuration is a hemispherical cylinder whose diameter is 40 mm with an overall length of 70 mm. The lengths of the aerospikes investigated are 1, 1.5, 2 and 2.5 times the base diameter of the cylinder and the radii of the aerodisks are varied between 0.05, 0.1, 0.15 and 0.2 times the diameter of the cylinder. Besides these, the position of the aerodisks is varied with the rearmost aerodisk placed at 25%, 50% and 75% along the length of the aerospike and the intermediate aerodisk for three-disk cases, positioned at 25%, 50% and 75% of the distance between the front and the rearmost disk. All the investigations have carried out at a freestream Mach number of 6.2 and Reynolds number of 2.64 × 107/m. It has been observed that the multidisk spikes are advantageous for the purpose of reduction of both aerodynamic drag and heating at hypersonic speed. The two aerodisk spiked configurations show better results in terms of aerodynamic heating and drag in comparison to the single-disk aerospikes while the three-disk spikes yield only a marginal reduction in aerodynamic drag over the two-disk configurations. For reduction of heat fluxes and heat transfer rates though, the three-disk configurations are extremely advantageous and give much larger reductions are compared to the two-disk configurations.

Forebody shock control devices for drag and aero-heating reduction: A comprehensive survey with a practical perspective

“…Adding a relatively larger tip, the aerodisk, further enhances the device effectiveness [25] over a wider range of Mach numbers [10] and incidence angles [26] or to compensate short spike length [5] despite the added drag on the aerodisk [27]. The Intermediate disks along the spike stem have shown a favorable role as well [28]. An aerodisk commonly has a circular projection however, it performs the best if its projection is similar in shape to that of the forebody [29].…”

“…However, an aeroheating penalty upon using such device was reported in [113]. The group of Yadav [28,114,115] -d same concept in which one or two more hemispherical aerodisks are added to locations along the spike stem. Monotonic drop in drag and aeroheating was reported by adding more disks with marginal benefits as the number of disks increases.…”

Aero-spike and aero-disk effects of on wave drag reduction of supersonic flow past over blunt body

“…The results show that the hemispherical spike at an 8° angle has a maximum reduction in drag of about 49.2%. Yadav et al (2018) numerically focused on the effect of spike length variation, disk size, the number of disk variations and their positions on drag reduction and aerodynamic heating. Both, single and multi aerodisk configurations show the highest drag reduction at an L/D ratio of 2.5.…”