Spike Effects on Drag Reduction for Hypersonic Lifting Body

Abstract

High lift-to-drag ratio is considered crucial for high altitude and long endurance hypersonic vehicles. One of the simplest and most useful methods is to install an aerospike in front of the vehicle's nose. In this paper, the flight aerodynamic characteristics are investigated by simulating and comparing the lifting-body with or without the aerospikes at Ma=8. The flow fields around aerospikes using different spike lengths and a hemispherical disk along with the lifting-body are analysed. The results of aerodynamic characteristics indicate that L/D=2 is the best ratio of spike length to nose diameter. By comparing with the baseline model, maximum drag reduction of the nose's part is 49.3% at =8º using hemispherical disk. In addition, three shapes of aerospike disks are compared to search for a best disk for hypersonic drag reduction. The best drag reduction is found for the double flat faced disk aerospike, which gives a pressure drag reduction of 60.5% of nose's part at =8º. Furthermore, when the flight angle of attack increases, the drag increases significantly. Employing certain installation angle is shown to effectively improve the drag reduction around the angle of attack and results in improving the lift-to-drag ratio. At the

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

“…They examined drag and aeroheating to a hemispherical forebody model equipped with various spike and aerodisk designs at Mach 6 and different incidence angles. The research group of Qin contributed with a number of numerical simulation studies on spiked bodies [30,31,42,52,60,69,87]. Drag and aeroheating reduction capabilities of a spike-aerodisk of different designs attached to a hemispherical model in a Mach 6 laminar freestream were investigated in [30,31].…”

“…In their survey paper on mechanical spike devices [11], Ahmed and Qin addressed the state-of-art (up to 2010) and their recent contributions. In [87], the benefits of fitting a double-disk aerospike to a winged lifting-body vehicle for different mounting and vehicle incidence angles were investigated.…”

“…A spike that is fitted inclined to the forebody symmetry axis was proposed by Thurman [106] and was found to add more lift to the vehicle. The concept was implemented recently by Deng et al [87] for lifting body configuration. A more advanced implementation of the concept, , that is maintained aligned with the freestream regardless to the vehicle incidence was proposed by Schülein [107,108].…”

“…Gopalakrishna and Saravanan used in their experimental-computational study [116] and confirmed further aeroheating reduction capabilities of this device. The same concept was utilized with application on a lifting vehicle configuration [87] and was found to improve the aerodynamic efficiency of the vehicle as well as reducing the drag. A concise summary for all spike-related literature is listed in Table A1 in the Appendix.…”

“…Real flight altitudes of supersonic and hypersonic vehicles were also addressed in the literature [119]. Various forebody configurations were examined including models for reentry vehicles [51,55], lifting bodies [29,52,87,120], and complete projectile configurations [121,122]. Design optimization of complete spiked forebody was also performed at different freestream conditions [62,69].…”