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Adiabatic heat bath

Zero-dimensional | Thermal non-equilibrium | Chemistry-vibration coupling

  Working directory located here.

  See Section 3.4. Relaxation of a Chemically-Reacting Mixture in
V. Casseau, R. C. Palharini, T. J. Scanlon, and R. E. Brown, "A Two-Temperature Open-Source CFD Model for Hypersonic Reacting Flows, Part One: Zero-Dimensional Analysis," Aerospace, vol. 3, no. 4, p. 34, 2016   [Full HTML→]

1. CASE SETUP

1.1 Mesh

The heat bath is composed of a single cubic cell of length 1 x 10-5 m.
All boundary patches are set to be of empty type.

1.2 Initial conditions

The initial conditions are given in 0/include/initialConditions:

  • p0 = 41,419.4 Pa
  • T0tr = 30,000 K
  • T0v = 1000 K
  • U0 = (0 0 0) m/s
  • X0N2 = 0.5
  • X0N = 0.5

1.3 Thermo-chemical models

This test case is using the following thermo-chemical models:

  • thermally-perfect gas (excluding the electronic energy contribution)
  • 1 irreversible reaction (Park 1993)
  • two-temperature model
    • V—T energy transfer: Landau-Teller, tabulated Millikan-White coefficients, Park’s correction
    • chemistry-vibration coupling: Park TTv, preferential model

1.4 Time controls

The time-step is constant and set to 1 x 10-9 s and the simulation stops after 10,000 iterations.

 

2. RUNNING

The following commands will execute blockMesh, checkMesh and hy2Foam in serial

./Allclean  
./Allrun

 

3. SOLUTION

On the following graphs, the tutorial case results are given by the solid lines:

Influence of the chemistry-vibration model and chemical rate constants on a chemically-reacting N2−N heat bath: (a) temperature versus time, and (b) normalised number density versus time

 

4. REGRESSION TESTING

Check that the results are matching the solution stored in gnuplot/solution/:

./Alltest


Contributor: Dr Vincent Casseau