Thermal protection systems for space vehicles: A review on technology development, current challenges and future prospects

Uyanna, Obinna; Najafi, Hamidreza

doi:10.1016/j.actaastro.2020.06.047

Cited by 330 publications

(104 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This relationship holds when the emitted electrons see no retarding electric field, they are not reflected back to the surface through collisions with the flowfield, nor do they see a virtual cathode created by space-charge limits. This current is then used to include an additional production term for the mass balance at the wall, as shown in Equation (5).…”

Section: Thermionic Emissionmentioning

confidence: 99%

“…However, if some material is allowed to decompose endothermically, such as in the case of phase change, the material breaking down will absorb more energy as it passes through and over the hot surface. This two-stage mechanism can carry away heat very effectively [5] and can be represented by Equation (1). For simplicity, the product gas is assumed to be at the wall enthalpy, h w .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of Computational Models for Electron Transpiration Cooling

et al. 2021

View full text Add to dashboard Cite

Recent developments in the world of hypersonic flight have brought increased attention to the thermal response of materials exposed to high-enthalpy gases. One promising concept is electron transpiration cooling (ETC) that provides the prospect of a passive heat removal mechanism, rivaling and possibly outperforming that of radiative cooling. In this work, non-equilibrium CFD simulations are performed to evaluate the possible roles of this cooling mode under high-enthalpy conditions obtainable in plasma torch ground-test facilities capable of long flow times. The work focuses on the test case of argon gas being heated to achieve enthalpies equivalent to post-shock conditions experienced by a vehicle flying through the atmosphere at hypersonic speed. Simulations are performed at a range of conditions and are used to calibrate direct comparisons between torch operating conditions and resulting flow properties. These comparisons highlight important modeling considerations for simulating long-duration, hot chamber tests. Simulation results correspond well with the experimental measurements of gas temperature, material surface temperature as well as measured current generated in the test article. Theoretical methods taking into consideration space charge limitations are presented and applied to provide design suggestions to boost the ETC effect in future experiments.

show abstract

Section: Thermionic Emissionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evaluation of Computational Models for Electron Transpiration Cooling

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Therefore, in order to protect the spacecraft from extremely severe thermal loads, thermal protection system (TPS) is necessary 1,2 . Among all methods related to thermal protection, polymer ablative materials (PAMs) are the most promising and have been studied up to now 3–5 . In the ablation process, the PAMs can form char layer and absorb heat, which will reduce the heat flow on the surface of the spacecraft.…”

Section: Introductionmentioning

confidence: 99%

Effect of hybrid cross‐linked polyphosphazene microspheres on ablative and mechanical properties of ethylene propylene diene monomer

Chen

He²,

Liu

et al. 2021

J of Applied Polymer Sci

View full text Add to dashboard Cite

Polymeric ablative materials (PAMs) are widely used in spacecraft currently for thermal insulation. However, it is challenging to find a single filler that can improve both ablative and mechanical properties of PAMs. In this study, a new type of hybrid cross‐linked polyphosphazene microspheres (PHC) is added to ethylene propylene diene monomer (EPDM) composites as a filler for the first time and its influence on the ablation, mechanical, and thermal properties of EPDM is investigated. The results show that the addition of 3 phr PHC increases the ablation performance by about 10% and enhances the mechanical properties by 20% approximately. In addition, the ablation mechanism is studied in accordance with SEM, FTIR, and Raman spectroscopy. On the one hand, PHC has the effect of catalyzing carbonization, thus increasing the rate of residual carbon; on the other hand, PHC changes the morphology of the char layer, forming a cross‐linked structure containing P─O─Si bonds on the surface. The findings regarding catalyzing carbonization and the special char layer structure could guide the design of ablative materials.

show abstract

“…Designs of heat-shielding panels for reusable spacecraft with an outer metal plate are being actively developed by leading experts from many countries [1,2]. Today it is becoming evident that the most effective thermal protection consists of individual tile-modules attached to the hull of the spacecraft.…”

Section: Introductionmentioning

confidence: 99%

About the possibility of application of laser vacuum welding for the integration of elements of heat-protective structures from powder materials

et al. 2021

View full text Add to dashboard Cite

The results of studying the process of laser vacuum welding of elements of heat-shielding panels made of heat-resistant dispersion-strengthened powder materials Ni-20Cr-6Al-Ti-Y2O3 of increased strength are presented. Such materials can be used to create ultralight heat-shielding panels, which are systems integrated on the surface of aircraft from typical modules of a cellular structure. Technical solutions of heat-insulating modules are considered, which are a cellular (honeycomb) structure consisting of two plates with a thickness of 0.1 to 0.14 mm, inside which there is a thin honeycomb filler. It is shown that the small thickness of the plates and the complexity of integrating the elements into a single system significantly impair the formation of a strong connection of such elements and do not allow the direct use of the known methods of diffusion welding or vacuum brazing. It has been established that laser welding of elements of heat-shielding structures in vacuum provides satisfactory strength of the structure of the heat-shielding element as a whole. Local heating at certain points prevents deformation of the parts to be joined during the welding process. The use of a pulsed Nd:Yag laser with a power of 400–500 W, operating in the frequency range of 50–200 Hz, allows welding with or without a filler powder. It was found that the use of filler additives practically does not affect the mechanical properties of the welded joint, however, it reduces the melt zone, while increasing the density of the welded joint. Based on the results obtained, it was concluded that it is possible to use laser vacuum welding for the integration of thin elements of heat-shielding modules. It is shown that a satisfactory joint strength is achieved by ensuring high cleanliness of the surfaces of elements before welding, maintaining a high vacuum (less than 10–2 Pa) and rational thermal loading of the surfaces of the elements to be integrated. The use of the proposed process makes it possible to obtain a stronger and denser seam in comparison with the known methods of soldering multicomponent powder dispersion-strengthened materials

show abstract

Thermal protection systems for space vehicles: A review on technology development, current challenges and future prospects

Cited by 330 publications

References 45 publications

Evaluation of Computational Models for Electron Transpiration Cooling

Evaluation of Computational Models for Electron Transpiration Cooling

Effect of hybrid cross‐linked polyphosphazene microspheres on ablative and mechanical properties of ethylene propylene diene monomer

About the possibility of application of laser vacuum welding for the integration of elements of heat-protective structures from powder materials

Contact Info

Product

Resources

About