PSI - Issue 50

V.G. Degtiar et al. / Procedia Structural Integrity 50 (2023) 40–49 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

49

10

As a result, in ablation an estimated coefficient of the FV lateral moment

z m was 2 – 3 times higher the

estimated for a standard asymmetry model without misalignment. 5. Conclusion

A complex of methods of accounting for structural inhomogeneities of elements of a thermal protection system made of C-C composites used to estimate ablated shapes of high-speed flight vehicles and corresponding methods of measuring and processing of the measured structural parameters of materials is presented. Methods and results of tomographic and electron microscopic measurements of the distributions of density, pores, shells over the volume of materials and methods of their processing to take into account the influence of summary equivalent parameters of large-scale and finely divided roughness on change in the ablated shapes are shown. A method of accounting for influence of the material graphitation degree on the ablation rate and results of the corresponding X-ray diffraction studies of C-C composites are presented. Influences of misalignment of the frame structure of C-C composites relative to the FV longitudinal axis on asymmetry of ablated shapes were assessed and showed that a lateral moment can increase by 2-3 times compared with the moments in case of an axisymmetric structure. References Znamenski, V. V., 1978. Numerical solution of an ablation equation. Izv. AN SSSR . MZHG, # 2, 147−154. Pchyolkin, Yu. D., 2014. An approximate method to calculate the ablation of mass of carbon materials in high-temperature flow. Cosmonautics and rocket engineering, issue 2 (75), 19 – 24. Kostin, G. F., Bulygin, M. G., Dementiev, O. N, et al., 2004. Influence of structural inhomogeneities of TPS C-C composites of hypersonic FVs on scatters in ablated shapes. Structures from composite materials, # 3, 3 – 15. Degtiar, V. G., Kostin, G. F., Saveliev, V. N. et al., 2014. Influence of structures of C-C composites on ablated shapes and aerodynamic characteristics of hypersonic aircraft. Structures from composite materials, # 4, 15 – 26. Degtiar, V. G., Saveliev, V. N., Kalashnikov, S. T., Khlybov, V. I., Kostin, G. F., Tyumentsev, V. A. et al., 2016. Investigation of roughness parameters of the MKU-4M-7 material, when applied in nose-pieces of Flight Vehicles (FVs) based on the results of electron microscopic study. Structures from composite materials, # 4, 35−43. Degtiar, V. G., Kalashnikov, S. T., Kostin, G. F., Saveliev, V. N., Tyumentsev, V. A., Khlybov, V. I., Shvaleva, R. K., 2018. Experimental analytical methodology used to define parameters of sandy-grained roughness on burned surfaces. Structures from composite materials, # 3, 29−39. Degtiar, V. G., Vinogradov, S. M., Kalashnikov, S. T., Kapranov, B. I., Kostin, G. F., Saveliev, V. N., Savichev, V. Yu., Shvaleva, R. K. Analysis of tomography examination of density distributed to volumes of samples from 4KMS-L. Structures from composite materials, # 3, 47−55. Degtiar, V. G., Saveliev, V. N., Kalashnikov, S. T., Khlybov, V. I., Kostin, G. F., Tyumentsev, V. A., Fazlitdinova, A. G., 2016. Investigation of roughness parameters of the MKU-4M-7 material, when applied in nose-pieces of Flight Vehicles (FVs) using X-ray diffraction measurements. Structures from composite materials, # 4, 44−51. Degtiar, V. G., Kalashnikov, S. T., Kapranov, B. I., Kostin, G. F., Savelyev, V. N., Tyumentsev, V. A., Khlybov, V. I. and Shvalyova, R. K., 2020. A complex of investigations of structures of carbon composites to support the analysis of changes in FV shapes and aerodynamic characteristics, AIP Conference Proceedings 2288, 020008 (2020);AIP Conference Proceedings > Volume 2288, Issue 1 >10.1063/5.0031899. Published Online: Oct. 26, 2020. https://doi.org/10.1063/5.0031899. Dirling, R., 1973. A method for Computing Roughwall Heat Transfer Rates on Reentry Nosetips. AYAA Paper, 73−76. Zolotaryov, S. L., Plevako, N. B., 2004. Experimental studies of relief of the surface of samples of materials at their damage in high-enthalpy flow. Cosmonautics and rocket engineering, Issue 36, 70−75.