Advanced Rocket Nozzles

Hagemann, G.; Immich, H.; Nguyen, Thong Van; Dumnov, G.

doi:10.2514/2.5354

Cited by 230 publications

(71 citation statements)

References 20 publications

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“…Figure 16a displays the pressure distribution showing the flowfield characteristics for the advanced airframe-integrated aerospike-type external nozzle configuration. The flowfield is similar to that seen in the full-length aerospike nozzle [13][14][15][16][17]19,22,23]. The expansion waves are emanating from the boattail lip.…”

Section: Advanced Configuration Of Airframe-integrated Aerospike Propsupporting

confidence: 51%

Thrust Augmentation by Airframe-Integrated Linear-Spike Nozzle Concept for High-Speed Aircraft

2018

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Abstract:The airframe-integrated linear-spike nozzle concept applied to an external nozzle for high-speed aircraft was evaluated with regard to the thrust augmentation capability and the trim balance. The main focus was on the vehicle aftbody. The baseline airframe geometry was first premised to be a hypersonic waverider design. The baseline aftbody case had an external nozzle comprised of a simple divergent nozzle and was hypothetically replaced with linear-spike external nozzle configurations. Performance evaluation was mainly conducted by considering the nozzle thrust generated by the pressure distribution on the external nozzle surface at the aftbody portion calculated by computer simulation at a given cruise condition with zero angle of attack. The thrust performance of the proposed linear-spike external nozzle concept was nearly equivalent to that of the baseline geometry though the wall surface area can be significantly reduced. This is because the design of the proposed concept had a compression wall for the exhaust flow, which resulted in increasing the wall pressure. The configuration with the boattail exhibited a potential for further improvement in thrust performance. The trim balance evaluation showed that the aerodynamic center location appeared as acceptable. Thus, benefits were obtained by employing the airframe-integrated linear-spike external nozzle concept.

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Section: Advanced Configuration Of Airframe-integrated Aerospike Propsupporting

confidence: 51%

Thrust Augmentation by Airframe-Integrated Linear-Spike Nozzle Concept for High-Speed Aircraft

2018

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“…Thrust-optimised contoured nozzles (TOC, Figure 9, right) are a step further from TIC nozzles where the near throat region has a shaped gradient of curve in the near throat region which corresponds to the greater expansion of the flow. The higher increase in the parabolic arc induces an internal shock that increases the pressure at the exit plane of the nozzle [10,11].…”

Section: Bell Nozzlementioning

confidence: 99%

“…When ascending to higher altitudes, the separation point leaves the inflection point and moves down the exit plane where a higher area ratio of the nozzle extension provides thrust with minimal losses caused due to the change in altitude pressure (Figure 10, left, top). Dual bell nozzles are also classified as altitude compensating nozzles (ACN) (Figure 10, right) [11,12]. …”

Section: Dual Bell and Contoured Nozzlementioning

confidence: 99%

Ramjet Nozzle Analysis for Transport Aircraft Configuration for Sustained Hypersonic Flight

2018

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For the past several decades, research dealing with hypersonic flight regimes has been restricted mainly to military applications. Hypersonic transportation could be a possible and affordable solution to travel in the medium term and there is renewed interest from several private organisations for commercial exploitation in this direction. Various combined cycle propulsion configurations have been proposed and the present paper deals with implications for the nozzle component of a ramjet configuration as part of one such combined cycle propulsion configuration. An investigation was undertaken for a method of turbine-based propulsion which enables the hypersonic vehicle to take off under its own power and propel the aircraft under different mission profiles into ramjet operational Mach regimes. The present study details an optimal method of ramjet exhaust expansion to produce sufficient thrust to propel the vehicle into altitudes and Mach regimes where scramjet operation can be initiated. This aspect includes a Computational Fluid Dynamics (CFD)-based geometric study to determine the optimal configuration to provide the best thrust values. The CFD parametric analysis investigated three candidate nozzles and indicated that the dual bell nozzle design produced the highest thrust values when compared to other nozzle geometries. The altitude adaptation study also validated the effectiveness of the nozzle thrust at various altitudes without compromising its thrust-producing capabilities. Computational data were validated against published experimental data, which indicated that the computed values correlated well with the experimental data.

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“…The linear aerospike nozzle is one of the most promising nozzle configurations for this kind of hypersonic vehicle because of its altitude compensating feature [1][2][3]. An engine employing an aerospike nozzle is capable of maintaining nearly optimal thrust performance from sea level to orbit, unlike that using a conventional bell-shaped nozzle, which reaches maximum performance only at one specific altitude (design altitude).…”

Section: Introductionmentioning

confidence: 99%

Performance Evaluation of Airframe-Integrated Aerospike Propulsion Systems in Off-Design Flight Conditions

Takahashi

Tomita

Tomioka

2015

53rd AIAA Aerospace Sciences Meeting

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The thrust performance of airframe-integrated linear aerospike propulsion systems for high-speed aircraft operated under off-design in-flight conditions was evaluated, based on performance prediction models established for linear aerospike nozzles by accounting for the freestream effect.The airframe configuration, equipped with a boattail appearing to the right upstream of the primary cell nozzle exit, enabled the freestream effect to be utilized for increasing the spike surface pressure.Performances of each thrust component were predicted by using the physics-based models established in separately performed studies. First, a parametric study was conducted on a rocket primary thruster with various design parameters. Then, an advanced concept with an airbreathing primary propulsion system was evaluated for its feasibility by comparing its thrust performance with that of a conventional rocket primary thruster. The benefit of the aerospike nozzle integrated into the airframe was also evaluated by comparing its thrust to a configuration without the aerospike nozzle.Results showed that the employment of the aerospike nozzle offered improved performance from takeoff to cruise phases. The advanced concept using the bypass airbreathing system for the primary thruster followed by the aerospike configuration exhibited further improvement in thrust by compensating for the boattail drag.

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Advanced Rocket Nozzles

Cited by 230 publications

References 20 publications

Thrust Augmentation by Airframe-Integrated Linear-Spike Nozzle Concept for High-Speed Aircraft

Thrust Augmentation by Airframe-Integrated Linear-Spike Nozzle Concept for High-Speed Aircraft

Ramjet Nozzle Analysis for Transport Aircraft Configuration for Sustained Hypersonic Flight

Performance Evaluation of Airframe-Integrated Aerospike Propulsion Systems in Off-Design Flight Conditions

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