Geometry optimization of a pintle nozzle for augmented thrust vectoring and steering using expansion waves

Baskaran, RV and Harisrinivasan, U and Sanal Kumar, VR (2018) Geometry optimization of a pintle nozzle for augmented thrust vectoring and steering using expansion waves. In: 36th AIAA Applied Aerodynamics Conference, 2018, 25 - 29 June 2018, Atlanta, Georgia.

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Abstract

In this paper, we have carried out detailed numerical studies on the geometry optimization of a pintle nozzle for thrust vectoring and steering using convex-shaped pintle-tip induced expansion waves. The numerical simulations have been carried out using a validated 2D density based implicit k-ω SST turbulence model. As a part of the code validation and calibration, the numerically predicted boundary-layer blockage at the Sanal flow choking condition for the channel flow is verified using the closed-form analytical model of Sanal Kumar V. R. et al. (AIP Advances, 8, 025315, 2018) and found excellent agreement with the exact solution. Note that while using the conventional pintle an overall thrust penalty on the order of 0.5 – 1 % was reported in the previous connected AIAA paper, which we could negate herein by facilitating a convex shape at the pintle-tip for generating expansion waves just before the nozzle exit plane. We concluded that there is an optimum expansion angle of the pintle-tip, defined herein as Roshan expansion angle, for a particular area ratio nozzle for getting the maximum benefits of the expansion waves in a wall bounded problem like CD nozzle flow for getting the highest momentum thrust. We observed that a pintle nozzle with given area ratio having Roshan expansion waves could augment the momentum thrust by 16.2 % while comparing a conventional pintle nozzle case. We concluded that due to the formation of Roshan expansion waves the pintle horizontal position dictating the nozzle throat area and the corresponding vertical coordinates declaring the shape of the divergent flow region are having a significant bearing on the augmented thrust vectoring and steering of chemical rockets. The novelty of the integrated shape is that, the aerodynamically optimized pintle nozzle ensures a shock-less flow inside the nozzle at the highest operating chamber pressure condition. This study is a pointer towards for the design optimization of a pintle nozzle capable to produce Roshan expansion waves for an improved thrust vectoring and the steering of aerospace vehicles.

Item Type:	Conference Paper
Publication:	2018 Applied Aerodynamics Conference
Publisher:	American Institute of Aeronautics and Astronautics Inc, AIAA
Additional Information:	The copyright for this article belongs to the American Institute of Aeronautics and Astronautics Inc, AIAA.
Keywords:	Aerodynamics; Automobile steering equipment; Boundary layers; Computational fluid dynamics; Expansion; Geometry; Nozzle design; Rockets; Turbulence models, Chamber pressure; Chemical rockets; Design optimization; Expansion angles; Geometry optimization; Nozzle exit plane; SST turbulence models; Vertical coordinates, Rocket nozzles
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering)
Date Deposited:	20 Aug 2022 08:41
Last Modified:	20 Aug 2022 08:41
URI:	https://eprints.iisc.ac.in/id/eprint/76024

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