2.2) Ablation
A spacecraft orbits in speeds of tens of kilometers per second. However, when it enters the
atmosphere of a planet, the spacecraft finds itself under a large aerodynamic resistance
which lowers its speed to hundreds of meters per second. During this phenomenon, the kinetic
energy is transformed into sound (< 1%) and thermal energies. This thermal energy is absorbed
by the atmosphere, as well as by the satellite structure. Therefore, it is necessary to
protect the satellite from thermal damage in order to recover its load after landing.
LABTUCAL has been researching on reactive hypersonic flows in cooperation with the Brazilian
Aeronautics Institute of Technology (Instituto Tecnológico da Aeronáutica - ITA) in order to
understand all physical phenomena involved in the energy flow during atmospheric reentry.
Currently the main focus of research is the development of project tools for a Thermal
Protection System (TPS) for the Brazilian retrievable satellite. Among the TPS possibilities,
LABTUCAL has chosen the use of an ablation TPS. Ablative TPS are passive. In other words,
they utilize the reentry thermal energy to sublime the material and therefore lower the structure
heating energy without the need for any electric or mechanic device. Such a system has been
successfully used in several space programs in many countries, including the Apollo Project of
NASA (North American Space Agency) and the EUREX Project of ESA (European Space Agency), as
well as in former USSR and China.
Publications: PIMENTEL, C.; AZEVEDO, J.; KORZENOWSKI, H.; MANTELLI, M. B. H. Chemical Equilibrium Inviscid Flow over Sara Re-Entry Vehicle. In: 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada. Jan. 10-13, 2005.
BRAGA, W. F.; MANTELLI, M. B. H.; AZEVEDO, J. L. F. A New Approach for the Heat Balance Integral Method Applied to Heat Conduction Problems. In: 43rd AIAA Aeroespace Sciences Meeting and Exhibit, 2005, Reno, 2005.
BRAGA, W. F.; MANTELLI, M. B. H.; AZEVEDO, J. L. F. Analytical Solution for One-Dimensional Semi-Infinite Heat Transfer Problem with Convection Boundary Condition. In: 38th AIAA Thermophysical Conference, 2005, Toronto, 2005.
BRAGA, W. F.; MANTELLI, M. B. H.; AZEVEDO, J. L. F. Approximate Analytical Solution for One-Dimensional Finite Ablation Problem with Constant Time Heat Flux. In: 37th AIAA Thermophysical Conference, 2004, Portland, 2004.
BRAGA, W. F.; MANTELLI, M. B. H.; AZEVEDO, J. L. F. Approximated Analytical Solution for One-Dimensional Ablation Problem with Time-Variable Heat Flux. In: 36th AIAA Thermophysical Conference, 2003, Orlando, Flórida, 2003.
ARRUDA, L. M. C.; BRAGA, W. F.; MANTELLI, M. B. H. Development of Experimental Apparatus for Thermal Characterization of Ablative Materials. In: XVII Congresso Internacional de Engenharia Mecânica, 2003, São Paulo (SP), 2003.
BRAGA, W. F.; MANTELLI, M. B. H. Electrical Analogy Modeling for One-Dimensional Ablation Problem. In: 8th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, 2002, Saint Louis. Reston, Va. : AIAA, American Institute of Aeronautis and Astronautics, 2002.
BRAGA, W. F.; MANTELLI, M. B. H. Solução Aproximada em Forma Analítica do Processo de Ablação Unidimensional. In: Congresso Brasileiro de Engenharia e Ciências Térmicas, 2002, Caxambu. Anais do Congresso Brasileiro de Engenharia e Ciências Térmicas. Rio de Janeiro: ABCM, 2002.
