Ablation modeling of thermal protection systems of blunt-nosed bodies at supersonic flight speeds

Download
index.pdf
2013
Şimşek, Buğra
Show full item record
279
views
387
downloads
The objective of this thesis is to predict shape change due to ablation and to find temperature distribution of the thermal protection system of a supersonic vehicle under aerodynamic heating by using finite element method. A subliming ablative is used as thermal protection material. Required material properties for the ablation analyses are found by using DSC (Differential Scanning Calorimetry) and TGA (Thermogravimetric Analysis) thermal analysis techniques. DSC is a thermal analysis technique that looks at how a material's specific heat capacity is changed by temperature and TGA is a technique in which the mass of a substance is monitored as a function of temperature. Moreover, oxyacetylene ablation tests are conducted for the subliming ablative specimens and measured recession values are compared with the analytically calculated values. Maximum difference between experimental results and analytical results is observed as 3% as seen in Table 7. For the finite element analyses, ANSYS Software is used. A numerical algorithm is developed by using programming language APDL (ANSYS Parametric Design Language) and element kill feature of ANSYS is used for simulation of ablation process. To see the effect of mesh size and time step on the solution of analyses, oxyacetylene test results are used. Numerical algorithm is also applied to the blunt-nosed section of a supersonic rocket which is made from subliming ablative material. Ablation analyses are performed for the nose section because nose recession is very important for a rocket to follow the desired trajectory and nose temperature is very important for the avionics in the inner side of the nose. By using the developed algorithm, under aerodynamic heating, shape change and temperature distribution of the nose section at the end of the flight are obtained. Moreover, effects of ablation on the trajectory of the rocket and on the flow around the rocket are examined by Missile DATCOM and CFD (computational fluid dynamics) analysis tools.
Aerodynamics, Supersonic., Supersonic planes., Ablation (Aerothermodynamics)., Aerothermodynamics.
http://etd.lib.metu.edu.tr/upload/12615414/index.pdf
https://hdl.handle.net/11511/22395
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

EXPERIMENTAL ANALYSIS AND TRANSIENT SIMULATION OF HEAT TRANSFER INSIDE THE FINNED TUBE ADSORBENT BED OF A THERMAL WAVE CYCLE
ÇAĞLAR, AHMET; Yamali, Cemil (Begell House, 2019-01-01)
Heat transfer enhancement inside the adsorbent bed of a thermal wave adsorption cooling cycle is investigated both experimentally and theoretically. Various adsorbent materials are tested using a finned tube adsorbent bed for the thermal wave cycle. The mathematical model is well defined, including a 2-D coupled heat and mass transfer analysis. This study presents the effects of heat transfer fluid velocity, regeneration temperature, condenser pressure, and particle diameter on the heat transfer enhancement...
Adsorption properties of a natural zeolite-water pair for use in adsorption cooling cycles
Solmus, Ismail; Yamali, Cemil; KAFTANOĞLU, BİLGİN; Baker, Derek Keıth; Caglar, Ahmet (2010-06-01)
The equilibrium adsorption capacity of water on a natural zeolite has been experimentally determined at different zeolite temperatures and water vapor pressures for use in an adsorption cooling system. The Dubinin-Astakhov adsorption equilibrium model is fitted to experimental data with an acceptable error limit. Separate correlations are obtained for adsorption and desorption processes as well as a single correlation to model both processes. The isosteric heat of adsorption of water on zeolite has been cal...
Perfect gas navier-stokes solutions hypersonic boundary layer and compression corner flows
Aziz, Şaduman; Çelenligil, Mehmet Cevdet; Department of Aerospace Engineering (2005)
The purpose of this thesis is to perform numerical solutions of hypersonic, high temperature, perfect gas flows over various geometries. Three dimensional, thin layer, compressible, Navier-Stokes equations are solved. An upwind finite difference approach with Lower Upper-Alternating Direction Implicit (LU-ADI) decomposition is used. Solutions of laminar, hypersonic, high temperature, perfect gas flows over flat plate and compression corners (qw=5°, 10°, 14°, 15°, 16°, 18° and 24°) with eight different free-...
Numerical analysis of ablation process on a two dimensional external surface
Aykan, Fatma Serap; Dursunkaya, Zafer (2008-01-01)
The thermal response analysis of an ablative material on a two dimensional external surface is performed. The method considers the whole domain as one continuous computational domain, eliminating the necessity to check the starting and ending positions of the decomposition zone. The current study solves the decomposition of the material at high temperatures by using the nth order Arrhenius equation but excludes the removal of char from the surface due to mechanical erosion or phase change and considers that...
Gradient-based optimization of micro-scale pressurized volumetric receiver geometry and flow rate
Akba, Tufan; Baker, Derek Keıth; Mengüç, M. Pınar (2023-02-01)
This study focuses on the design optimization of a micro-scale pressurized volumetric receiver by changing geometry and flow rate constrained by the volume, outlet air temperature, and outer surface temperature. The pressurized volumetric receiver model is replicated from an existing model, which assumes constant air pressure and neglects the convection loss from the cavity. The existing model is revised from a solver to a design optimizer. The replicated model is restructured using OpenMDAO (Open-source Mu...
Citation Formats
B. Şimşek, “Ablation modeling of thermal protection systems of blunt-nosed bodies at supersonic flight speeds,” M.S. - Master of Science, Middle East Technical University, 2013.
METU IIS - Integrated Information Service open@metu.edu.tr