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- Mesoscale Surface Combustion Modeling of Metalized Solid Fuel
- Hong-Suk Choi, SangYeop Han, Jai-ick Yoh
- We have revisited the complex surface burning of metalized energetic substances where the micro and nano metal particles and oxidizers chemically interact …
- We have revisited the complex surface burning of metalized energetic substances where the micro and nano metal particles and oxidizers chemically interact in the inert binder confinement. Both thermal and interfacial behaviors of the particles on the burning front during convective and diffusive thermal transport were investigated. Highly complex processes take place in three specific regions: the outflow region exposed to the ambient air consists of hot product gases with gasified metal oxides, the in-between melt layer comprised of reacting particles in condensed phase, and the inner region unreacted while kept at temperature below the melting point. We focus on the melt layer undergoing chemical reactions of a mixture of zirconium and potassium perchlorate, also known as the NASA Standard Initiator (NSI). The complex interface evolution is tracked via the level sets, and the finite chemical reaction rate law is constructed based on the calorimetry data for determining the activation energy and heat of reaction. Both slow and fast reactions are investigated to address the mesoscale effects of thermochemical and thermomechanical behaviors of metalized energetic substances that involve multi-physical interactions amongst metals, oxides, binder, and ambient air. The findings elucidate that there exists a strong competition between the hydrodynamic pressure induced from hot product gas generation and the interfacial interactions associated with deforming particles inside the melt layer during combustion. - COLLAPSE
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- Investigation on Thermoacoustic Instability in a Hydrogen Combustion System Using an Analytical Approach
- S.M.Zohair H.Shah, Junwoo Jung, Myunggon Yoon, Daesik Kim
- This paper presents a one-dimensional thermo-acoustic model for a single-nozzle gas turbine combustor with a premixer from the so-called network approach. The …
- This paper presents a one-dimensional thermo-acoustic model for a single-nozzle gas turbine combustor with a premixer from the so-called network approach. The analytic combustor model is verified with a target combustor by numerical simulations with COMSOL Multiphysics (3D FEM solver of the Helmholtz equation), and by experiments. It is found that the resonances and mode shapes from our analytic model are reasonably close to numerical and experimental ones. Combining the analytic thermo-acoustic model with a typical flame dynamical model, the effects of mean flow on the resonance and combustion instability of the combustion system are investigated. The hydrogen ratio in the fuel changes flame dynamics and consequently it has an effect on combustion instability of the combustion system. This hydrogen ratio is also analytically studied making use of the analytic combustor model and a popular flame model. - COLLAPSE
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- Theoretical Understanding of the Effects of High-density Energetic Particles on the Ramjet Performance
- Sasi Kiran Palateerdham, Abdul Rahman, Antonella Ingenito, Sri Nithya Mahottamananda, Yash Pal
- The performance of solid fuel ramjet engines depends on both the heat of reaction and density of the fuel, which are essential …
- The performance of solid fuel ramjet engines depends on both the heat of reaction and density of the fuel, which are essential factors for optimizing specific impulse and density-specific impulse. Density-specific impulse is calculated as the product of fuel composition density and specific impulse, reflecting not only fuel efficiency but also volumetric considerations that influence vehicle design and aerodynamics. This effect on design is particularly relevant for the lift-to-drag ratio (L/D), which plays a crucial role in overall vehicle efficiency. Specific impulse increases with the square root of flame temperature, while density-specific impulse improves linearly with fuel density. Enhancing fuel density through the addition of energetic particles and metal additives can optimize volumetric performance, while specific impulse benefits from additives like CuO and PTFE, which increase combustion temperature. This study aims to enhance density-specific impulse in ramjet fuels by introducing high-energy metals, including aluminum (Al), boron (B), and magnesium (Mg), into an HTPB-based fuel matrix, with CuO and PTFE added to increase specific impulse. The performance characteristics of these solid fuel compositions were evaluated using NASA’s CEA code, providing a detailed comparison of the compositions and their impact on ramjet performance. The findings offer valuable insights into fuel formulation strategies that enhance both density-specific impulse and overall combustion efficiency, supporting the development of optimized solid fuels for ramjet applications. - COLLAPSE
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- Guidelines for the Safe Handling of Hypergolic Propellants in Development of Space Propulsion Systems
- Yeongjun Ju, Chanju Song, Bok Jik Lee
- Hypergolic propellants offer long-term storage stability, repetitive ignition capability, and high specific impulse. Due to these advantages, hypergolic propellants have been widely …
- Hypergolic propellants offer long-term storage stability, repetitive ignition capability, and high specific impulse. Due to these advantages, hypergolic propellants have been widely used in spacecraft for long-term missions. Advanced countries in space technology, such as the United States and Japan, have conducted various experiments, including drop tests and impinging jet tests, to study the characteristics of hypergolic propellants, which are essential components of spacecraft. In Korea, to achieve the goal of launching a lunar lander by 2032, the development of hypergolic propellant rocket engines is necessary, underscoring the need for research on hypergolic propellants. However, due to the high toxicity of hypergolic propellants, proper guidelines for the safe handling are required prior to conducting experiments. This paper reviews trends in experimental research and establishes safe handling guidelines to enable researchers to conduct experiments with hypergolic propellants efficiently and safely. - COLLAPSE
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- A Shock-tube Study of Structural Stability and Morphological Characteristics of Hexagonal-shaped Zinc Oxide Nanomaterials
- Kiwon Kim, P. Sivaprakash, S. A. Martin Britto Dhas, Ikhyun Kim
- Shock wave recovery experiments on crystalline solids constitute a prominent research area within the aerospace field. In this study, we investigated the …
- Shock wave recovery experiments on crystalline solids constitute a prominent research area within the aerospace field. In this study, we investigated the response of zinc oxide (ZnO) to powder diffraction and morphological analysis. X-ray diffraction data indicate that the material retains its hexagonal crystalline structure under shock-loaded conditions. Scanning electron microscopy reveals that the agglomeration and size of the particles increase due to the fusion effect of shock loading, resulting in the clustering of individual particles into larger formations. The shock wave recovery experiment demonstrates that ZnO nanoparticles exhibit exceptional stability against shock waves, suggesting their potential suitability for aerospace and military applications. - COLLAPSE
Journal Informaiton
Journal of Propulsion and Energy
Journal of Propulsion and Energy
The Korean Society of Propulsion Engineers
한국추진공학회
Room 502, The Korean Society of Propulsion Engineers, 28, Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea
Tel: 82-42-822-6472 / Fax: 82-42-822-6472 / E-mail: kspe@kspe.org Copyright© The Korean Society of Propulsion Engineers. Powered by APUB
Tel: 82-42-822-6472 / Fax: 82-42-822-6472 / E-mail: kspe@kspe.org Copyright© The Korean Society of Propulsion Engineers. Powered by APUB