Presentation of the 2011 Ablation Test Case
Start Date
3-3-2011 8:30 AM
Description
Objectives
Three types of material-response codes have been identified in the community:
- Type 1: CMA-type codes (heat transfer, pyrolysis decomposition, simplified transport of the pyrolysis gases, equilibrium chemistry);
- Type 2: CMA model augmented with an averaged momentum equation for the transport of the pyrolysis gases;
- Type 3: Higher fidelity codes (possibly including finite-rate chemistry, multi-component diffusion, etc).
A test case with two objectives has been defined:
- Inter-calibration of codes of the same type (focus: numerical methods and data interpretation);
- Comparison of codes of different types (focus: modeling approach).
2011 Test case
For this first inter-comparison exercise, a simple one-dimensional test case without surface recession has been defined. The goal is to compare the in-depth physics and chemistry models implemented in the codes. A fixed temperature of 1644K and a fixed pressure of 1 Atm are imposed on one end of a five-centimeter sample of charring material. On the other end, the sample is assumed adiabatic and impermeable. The duration of the test is one minute. The initial conditions are as follows: temperature of 298K, atmospheric pressure. The initial gas composition in the material is left open. The charring material of the 2011 test case is a theoretical low-density fibrous ablator, called TACOT (Theoretical Ablative Composite for Open Testing). The properties of this material have been defined using literature data to enable open diffusion. Input data needed for the three types of codes are furnished: composition and microstructure, thermal properties, transport properties, pyrolysis model, finite-rate chemistry of the pyrolysis gases, thermo-chemical properties. The participants may use all or parts of the furnished properties. A baseline solution from a type 1 code (FIAT) is provided. Participants are invited to plot their results against the baseline for visual comparison and are invited to discuss them during the workshop [5 minute presentations and posters]. Participants are also invited to provide their output file for statistical analysis by the NASA Thermal Performance Database (TPDB) team [15 minute presentation].
Outlook
More elaborated test cases will be defined for next year (surface recession, multi-dimensional) and will be discussed at the end of the session [15 minute discussion].
Presentation of the 2011 Ablation Test Case
Objectives
Three types of material-response codes have been identified in the community:
- Type 1: CMA-type codes (heat transfer, pyrolysis decomposition, simplified transport of the pyrolysis gases, equilibrium chemistry);
- Type 2: CMA model augmented with an averaged momentum equation for the transport of the pyrolysis gases;
- Type 3: Higher fidelity codes (possibly including finite-rate chemistry, multi-component diffusion, etc).
A test case with two objectives has been defined:
- Inter-calibration of codes of the same type (focus: numerical methods and data interpretation);
- Comparison of codes of different types (focus: modeling approach).
2011 Test case
For this first inter-comparison exercise, a simple one-dimensional test case without surface recession has been defined. The goal is to compare the in-depth physics and chemistry models implemented in the codes. A fixed temperature of 1644K and a fixed pressure of 1 Atm are imposed on one end of a five-centimeter sample of charring material. On the other end, the sample is assumed adiabatic and impermeable. The duration of the test is one minute. The initial conditions are as follows: temperature of 298K, atmospheric pressure. The initial gas composition in the material is left open. The charring material of the 2011 test case is a theoretical low-density fibrous ablator, called TACOT (Theoretical Ablative Composite for Open Testing). The properties of this material have been defined using literature data to enable open diffusion. Input data needed for the three types of codes are furnished: composition and microstructure, thermal properties, transport properties, pyrolysis model, finite-rate chemistry of the pyrolysis gases, thermo-chemical properties. The participants may use all or parts of the furnished properties. A baseline solution from a type 1 code (FIAT) is provided. Participants are invited to plot their results against the baseline for visual comparison and are invited to discuss them during the workshop [5 minute presentations and posters]. Participants are also invited to provide their output file for statistical analysis by the NASA Thermal Performance Database (TPDB) team [15 minute presentation].
Outlook
More elaborated test cases will be defined for next year (surface recession, multi-dimensional) and will be discussed at the end of the session [15 minute discussion].