Abstract

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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

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