• Journal of Aerospace System Engineering
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• v.16 no.4
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• pp.1-9
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• 2022

A design factor analysis was conducted to reduce the thrust reduction in the off-design, due to the driving of the aerospike pintle nozzle. The close (NPR 100) as well as the open (NPR 11) stroke were fixed, as under-expansion conditions. The pintle contour, pintle head radius (R), cowl angle (θ), and cowl exit length (L) were selected as design factors. The change in thrust was analyzed, using a verified numerical analysis technique. First, the pintle head radius and the length of the cowl exit had little influence on the thrust. The cowl angle changed the mass flow rate by affecting the effective nozzle throat area, and created a reverse pressure gradient at the cowl exit. As a result of applying the dual aerospike contour, it was confirmed that the thrust in the design-off increased by approximately 1.2%, compared to the reference case and by approximately 3.4% compared to the worst case.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.28-34
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• 2019

The thrust control calculation according to the operation of plug nozzle for cold air test and the analysis of the flow characteristics of the pintle shape and operation pressure are performed. The numerical computation was verified by comparing the flow structure and the coefficient of thrust with the experimental data. It was confirmed that the nozzle throat was formed at the design position on each pintle shape, and thrust control up to 1:8 was achieved only by the stroke change. Finally, although the aerospike nozzle is autonomous, it is unfavorable in the under_expansion condition, if it is designed for a very low nozzle pressure ratio.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.237-240
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• 2011

Numerical simulation was carried out to investigate the effect of pintle inflection point on the performance of the SNECMA modulatable thrust devices. Results show that the effect of inflection points in the pintle is to decrease aerodynamic load while maintaining required thrust level.