Regression Rate Enhancement of Hybrid Rockets by Introducing Novel Distributed Tube Injector

2021 ◽  
pp. 1-12
Author(s):  
Mehmet Kahraman ◽  
Ibrahim Ozkol ◽  
M. Arif Karabeyoglu
Keyword(s):  
Rate Enhancement ◽  
Regression Rate ◽  
Hybrid Rockets

scholarly journals Challenges of Ablatively Cooled Hybrid Rockets for Satellites or Upper Stages

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 190
Author(s):  
Francesco Barato
Keyword(s):  
Combustion Chamber ◽  
Solid Fuel ◽  
Diameter Ratio ◽  
Propulsion System ◽  
Burning Time ◽  
Regression Rate ◽  
Hybrid Propulsion ◽  
Deep Impact ◽  
Time Ratio ◽  
Hybrid Rockets

Ablative-cooled hybrid rockets could potentially combine a similar versatility of a liquid propulsion system with a much simplified architecture. These characteristics make this kind of propulsion attractive, among others, for applications such as satellites and upper stages. In this paper, the use of hybrid rockets for those situations is reviewed. It is shown that, for a competitive implementation, several challenges need to be addressed, which are not the general ones often discussed in the hybrid literature. In particular, the optimal thrust to burning time ratio, which is often relatively low in liquid engines, has a deep impact on the grain geometry, that, in turn, must comply some constrains. The regression rate sometime needs to be tailored in order to avoid unreasonable grain shapes, with the consequence that the dimensional trends start to follow some sort of counter-intuitive behavior. The length to diameter ratio of the hybrid combustion chamber imposes some packaging issues in order to compact the whole propulsion system. Finally, the heat soak-back during long off phases between multiple burns could compromise the integrity of the case and of the solid fuel. Therefore, if the advantages of hybrid propulsion are to be exploited, the aspects mentioned in this paper shall be carefully considered and properly faced.

scholarly journals Biphasic Dispersion Fuels for High-Regression-Rate Hybrid Rockets

2019 ◽  
Vol 35 (5) ◽  
pp. 964-972 ◽  
Author(s):  
Joshua D. Mathews ◽  
Jason R. Gabl ◽  
Timothée L. Pourpoint
Keyword(s):  
Regression Rate ◽  
Hybrid Rockets

Role of Injection in Hybrid Rockets Regression Rate Behaviour

2005 ◽  
Vol 21 (4) ◽  
pp. 606-612 ◽  
Author(s):  
Carmine Carmicino ◽  
Annamaria Russo Sorge
Keyword(s):  
Regression Rate ◽  
Hybrid Rockets ◽  
Rate Behaviour

scholarly journals Numerical Simulations of the Internal Ballistics of Paraffin–Oxygen Hybrid Rockets at Different Scales

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 213
Author(s):  
Mario Tindaro Migliorino ◽  
Daniele Bianchi ◽  
Francesco Nasuti
Keyword(s):  
Numerical Simulations ◽  
Radiation Effects ◽  
Scale Effects ◽  
Numerical Approach ◽  
Surface Radiation ◽  
Rocket Engines ◽  
Regression Rate ◽  
Internal Ballistics ◽  
Hybrid Rockets ◽  
Time Space

Hybrid rockets are considered a promising future propulsion alternative for specific applications to solid or liquid rockets. In order to raise their technology readiness level, it is important to perform predictive numerical simulations of their internal ballistics. The objective of this work is to describe and validate a numerical approach based on Reynolds-averaged Navier–Stokes simulations with sub-models for fluid–surface interaction, radiation, chemistry, and turbulence. Particular attention is given to scale effects by considering two different paraffin–oxygen hybrid rocket engines and a simplified grain evolution approach from the initial to the final port diameter. Moreover, a mild sensitivity of the computed regression rate to paraffin’s melting temperature, surface radiation emissivity, and Schmidt numbers is observed. Results highlight the increasing importance of radiation effects at larger scales and pressures. A numerical rebuilding of regression rate and pressure is obtained with simulations at the time-space-averaged port diameter, producing a reasonable agreement with the available experimental data, but a noticeable improvement is obtained by considering the grain evolution in time.

Development of Scalable Space-Time Averaged Regression Rate Expressions for Hybrid Rockets

2007 ◽  
Vol 23 (4) ◽  
pp. 737-747 ◽  
Author(s):  
M. Arif Karabeyoglu ◽  
Brian J. Cantwell ◽  
Greg Zilliac
Keyword(s):  
Space Time ◽  
Regression Rate ◽  
Hybrid Rockets

Nickel acetylacetonate as decomposition catalyst for HTPB-based fuels: Regression rate enhancement effects

Fuel ◽  
2021 ◽  
Vol 305 ◽  
pp. 121539
Author(s):  
Hongsheng Yu ◽  
Suhang Chen ◽  
Xiaodong Yu ◽  
Wei Zhang ◽  
Christian Paravan ◽  
...  
Keyword(s):  
Nickel Acetylacetonate ◽  
Rate Enhancement ◽  
Regression Rate

scholarly journals Nano-Sized and Mechanically Activated Composites: Perspectives for Enhanced Mass Burning Rate in Aluminized Solid Fuels for Hybrid Rocket Propulsion

Aerospace ◽  
2019 ◽  
Vol 6 (12) ◽  
pp. 127 ◽  
Author(s):  
Paravan
Keyword(s):  
Burning Rate ◽  
Solid Fuel ◽  
Mass Flux ◽  
High Speed ◽  
Rate Data ◽  
Mass Burning Rate ◽  
Diffusion Distance ◽  
Metal Combustion ◽  
Rate Enhancement ◽  
Regression Rate

This work provides a lab-scale investigation of the ballistics of solid fuel formulations based on hydroxyl-terminated polybutadiene and loaded with Al-based energetic additives. Tested metal-based fillers span from micron- to nano-sized powders and include oxidizer-containing fuel-rich composites. The latter are obtained by chemical and mechanical processes providing reduced diffusion distance between Al and the oxidizing species source. A thorough pre-burning characterization of the additives is performed. The combustion behaviors of the tested formulations are analyzed considering the solid fuel regression rate and the mass burning rate as the main parameters of interest. A non-metallized formulation is taken as baseline for the relative grading of the tested fuels. Instantaneous and time-average regression rate data are determined by an optical time-resolved technique. The ballistic responses of the fuels are analyzed together with high-speed visualizations of the regressing surface. The fuel formulation loaded with 10 wt.% nano-sized aluminum (ALEX-100) shows a mass burning rate enhancement over the baseline of 55% ± 11% for an oxygen mass flux of 325 ± 20 kg/(m2∙s), but this performance increase nearly disappears as combustion proceeds. Captured high-speed images of the regressing surface show the critical issue of aggregation affecting the ALEX-100-loaded formulation and hindering the metal combustion. The oxidizer-containing composite additives promote metal ignition and (partial) burning in the oxidizer-lean region of the reacting boundary layer. Fuels loaded with 10 wt.% fluoropolymer-coated nano-Al show mass burning rate enhancement over the baseline >40% for oxygen mass flux in the range 325 to 155 kg/(m2∙s). The regression rate data of the fuel composition loaded with nano-sized Al-ammonium perchlorate composite show similar results. In these formulations, the oxidizer content in the fuel grain is <2 wt.%, but it plays a key role in performance enhancement thanks to the reduced metal–oxidizer diffusion distance. Formulations loaded with mechanically activated ALEX-100–polytetrafluoroethylene composites show mass burning rate increases up to 140% ± 20% with metal mass fractions of 30%. This performance is achieved with the fluoropolymer mass fraction in the additive of 45%.

Sign in / Sign up

Export Citation Format

Share Document