An Experimental Study on the Ablation Properties of Carbon/Carbon Composites Using Thermal Plasma

2020 ◽  
Vol 12 (9) ◽  
pp. 1271-1277
Author(s):  
Philyong Oh ◽  
Hoseok Kim ◽  
Boram Kang ◽  
Bong Guen Hong
Keyword(s):  
Heat Flux ◽  
Wind Tunnel ◽  
Thermal Protection ◽  
Carbon Composites ◽  
Vacuum Plasma Spray ◽  
Thermoelectric Generators ◽  
Test Results ◽  
Erosion Rates ◽  
Vacuum Plasma ◽  
The Matrix

The ablation properties of two carbon/carbon (C/C) composites currently considered as thermal protection materials for radioisotope thermoelectric generators (RTGs) were investigated using a plasma wind tunnel with a heat flux between the range of 2–4 MW/m2. The ablation properties were identified through an analysis of erosion rates and microstructures after testing. During ablation, erosion reactions of the matrix were faster than those of fibers and pores, and the defects and cracks between the fibers and matrix grew. The fibers eroded from their outer surface and ablation led to the formation of sharp tapered tips. Lower density C/C composites appeared to lose more matrix than higher density C/C composites. The erosion rate increased with heat flux. The ablation properties were compared with the test results using a vacuum plasma spray (VPS) facility and an E-beam facility. It was shown that both thermochemical and thermomechanical erosion occurred via oxygen in the plasma flow, and a rapid high-pressure heat stream occurred in tests using the plasma wind tunnel while only thermal ablation occurred in tests using the VPS and E-beam facilities.

Characteristics of a plasma wind tunnel for the development of thermal protection materials

2017 ◽  
Vol 121 (1240) ◽  
pp. 821-834 ◽  
Author(s):  
B. G. Hong ◽  
B. R. Kang ◽  
J. C. Choi ◽  
P. Y. Oh
Keyword(s):  
Wind Tunnel ◽  
Plasma Flow ◽  
Thermal Protection ◽  
Plasma Source ◽  
Carbon Composites ◽  
Diagnostic Systems ◽  
Supersonic Plasma ◽  
The Matrix ◽  
National University ◽  
Arc Plasma Torch

ABSTRACTThermal plasma wind tunnels with power of 0.4 MW and 2.4 MW have been constructed at Chonbuk National University (CBNU) in Korea. This facility is capable of producing a heat flux greater than 10 MW/m2, a level that is relevant for testing thermal protection materials that are used for re-entry vehicles in space transportation. A segmented arc plasma torch was adopted as a plasma source; this was designed to have high thermal efficiency and long life, and to produce a supersonic plasma flow with enthalpy greater than 10 MJ/kg. We investigated the characteristics of the supersonic plasma flow using intrusive and non-intrusive diagnostic systems. Ablation characteristics of potential thermal protection materials such as carbon/carbon composites and graphite were investigated with the plasma wind tunnel. Cracks and pores in the materials accelerated the erosion. For carbon/carbon composites, the pores grew and the cracks which occurred at the interfaces between the carbon fibres and the matrix propagated, while for the graphite, the erosion started at the pores and peeled off the surface.

Vacuum Plasma Spray Turbine Bucket Coating Development

1985 ◽  
Author(s):  
J. H. Wood ◽  
P. W. Schilke ◽  
M. F. Collins
Keyword(s):  
Low Temperature ◽  
Gas Turbine ◽  
Plasma Spray ◽  
Hot Corrosion ◽  
Development Work ◽  
Vacuum Plasma Spray ◽  
Test Results ◽  
General Electric ◽  
Vacuum Plasma ◽  
Turbine Bucket

This paper describes the vacuum plasma spray (VPS) turbine bucket coating development work conducted by the General Electric Company, Gas Turbine Division. The potential for corrosion in gas turbine buckets is described, and examples of the different types of hot corrosion are shown. Development of the first VPS coating (PLASMAGUARD* GT-29) is discussed, and corrosion laboratory burner test and field test results are presented. Coating development work aimed at low-temperature hot-corrosion conditions is also summarized. Laboratory test results on a new PLASMAGUARD coating (GT-43) developed for low-temperature hot corrosion are presented. The new General Electric Gas Turbine Division VPS coating manufacturing facility used to apply these coatings is also described.

scholarly journals Heat Transfer and Ablation Prediction of Carbon/Carbon Composites in a Hypersonic Environment Using Fluid-Thermal-Ablation Multiphysical Coupling

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Xuewen Sun ◽  
Haibo Yang ◽  
Tao Mi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Field ◽  
Thermal Ablation ◽  
Thermal Protection ◽  
Leading Edge ◽  
Coupling Model ◽  
Carbon Composites ◽  
Hypersonic Vehicles ◽  
Lateral Area

Carbon/carbon composites are usually used as a thermal protection material in the nose cap and leading edge of hypersonic vehicles. In order to predict the thermal and ablation response of a carbon/carbon model in a hypersonic aerothermal environment, a multiphysical coupling model is established taking into account thermochemical nonequilibrium of a flow field, heat transfer, and ablation of a material. A mesh movement algorithm is implemented to track the ablation recession. The flow field distribution and ablation recession are studied. The results show that the fluid-thermal-ablation coupling model can effectively predict the thermal and ablation response of the material. The temperature and heat flux in the stationary region of the carbon/carbon model change significantly with time. As time goes on, the wall temperature increases and the heat flux decreases. The ablation in the stagnation area is more serious than in the lateral area. The shape of the material changes, and the radius of the leading edge increases after ablation. The fluid-thermal-ablation coupling model can be used to provide reference for the design of a thermal protection system.

scholarly journals The inverse problem in zero linear ablation of aluminizing carbon composites under high heat flux

2013 ◽  
Vol 17 (5) ◽  
pp. 1323-1327 ◽  
Author(s):  
Haiming Huang ◽  
Weijie Li ◽  
Chenghai Xu ◽  
Xiaoliang Xu
Keyword(s):  
Heat Flux ◽  
Volume Fraction ◽  
Thermal Protection ◽  
Thermal Environment ◽  
Shape Change ◽  
High Heat ◽  
Carbon Composites ◽  
High Heat Flux ◽  
Linear Ablation ◽  
Heat Response

The concept of zero linear ablation is introduced to describe the mass ablation without shape change, and it is employed to design thermal protection materials under an extreme thermal environment. Aluminizing carbon composites are used as a sample to study numerically the heat response. As indicated in the numerical results, the shape of the composites did not change under a high heat flux because the phase transition (melt or evaporation) of aluminum can absorb a lot of energy before the ablation of carbon, and the zero linear ablation depends on not only the volume fraction of aluminum, but also the heating period and the heat flux.

scholarly journals Design of New Carbon-Phenolic Ablators: Manufacturing, Plasma Wind Tunnel Tests and Finite Element Model Rebuilding

2021 ◽  
Author(s):  
L. Paglia ◽  
V. Genova ◽  
J. Tirillò ◽  
C. Bartuli ◽  
A. Simone ◽  
...  
Keyword(s):  
Heat Flux ◽  
Finite Element ◽  
Wind Tunnel ◽  
Finite Element Model ◽  
Thermal Protection ◽  
Experimental Tests ◽  
Element Model ◽  
High Energy ◽  
Space Vehicles ◽  
Mechanical And Thermal Properties

AbstractAblative materials represent a widespread solution for shielding space vehicles from overheating during a reentry phase in atmosphere where the high heating fluxes and the consequent high temperatures cannot be compatible with the vehicle structure and with the safety of the payload and/or the crew. In this work, two different kinds of carbon-phenolic ablators with a density of 0.3 g/cm3 were manufactured and their mechanical and thermal properties were experimentally evaluated. The thermal protection performances of the developed ablators were assessed in a hypersonic plasma wind tunnel facility, setting representative enthalpy and heat flux conditions (6 and 13 MW/m2), consistent with atmospheric reentry missions from high energy orbits. Data of the experimental tests were compared with the results obtained by a finite element model built up for these materials with the commercial software SAMCEF Amaryllis. All results enlighten the good performances of the ablators under severe heat flux conditions and outline their operating limits.

Rancang Bangun Piranti Lunak Pengolah Data Pasca Pengujian Terowongan Angin Kecepatan Rendah Indonesia

2016 ◽  
Vol 7 (2) ◽  
pp. 131-138
Author(s):  
Ivransa Zuhdi Pane
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Effective Solution ◽  
Post Processing ◽  
Prototype Development ◽  
Design Activities ◽  
Index Terms ◽  
Test Objects ◽  
Processing Requirement

Data post-processing plays important roles in a wind tunnel test, especially in supporting the validation of the test results and further data analysis related to the design activities of the test objects. One effective solution to carry out the data post-processing in an automated productive manner, and thus eliminate the cumbersome conventional manual way, is building a software which is able to execute calculations and have abilities in presenting and analyzing the data in accordance with the post-processing requirement. Through several prototype development cycles, this work attempts to engineer and realize such software to enhance the overall wind tunnel test activities. Index Terms—software engineering, wind tunnel test, data post-processing, prototype, pseudocode

scholarly journals Characterization of the Structure, Mechanical Properties and Erosive Resistance of the Laser Cladded Inconel 625-Based Coatings Reinforced by TiC Particles

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2225
Author(s):  
Aleksandra Kotarska ◽  
Tomasz Poloczek ◽  
Damian Janicki
Keyword(s):  
Laser Cladding ◽  
Inconel 625 ◽  
Matrix Composites ◽  
Erosion Rates ◽  
Laser Cladding Process ◽  
Composition Variation ◽  
The Matrix ◽  
Reinforcing Material ◽  
Inconel 625 Superalloy

The article presents research in the field of laser cladding of metal-matrix composite (MMC) coatings. Nickel-based superalloys show attractive properties including high tensile strength, fatigue resistance, high-temperature corrosion resistance and toughness, which makes them widely used in the industry. Due to the insufficient wear resistance of nickel-based superalloys, many scientists are investigating the possibility of producing nickel-based superalloys matrix composites. For this study, the powder mixtures of Inconel 625 superalloy with 10, 20 and 40 vol.% of TiC particles were used to produce MMC coatings by laser cladding. The titanium carbides were chosen as reinforcing material due to high thermal stability and hardness. The multi-run coatings were tested using penetrant testing, macroscopic and microscopic observations, microhardness measurements and solid particle erosive test according to ASTM G76-04 standard. The TiC particles partially dissolved in the structure during the laser cladding process, which resulted in titanium and carbon enrichment of the matrix and the occurrence of precipitates formation in the structure. The process parameters and coatings chemical composition variation had an influence on coatings average hardness and erosion rates.

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