Accommodation coefficient (Cook theory)
[alpha] = CL_mod_aeroPanelAlpha(alpha_k, m_mol_mass, m_mol_mass_p)
Computes the accommodation coefficient.
According to the COOK theory, the accommodation coefficient is given by:
alpha = alpha_k * mu / (1 + mu)^2
with:
mu = m_mol_mass / m_mol_mass_p
m_mol_mass: Mean molar mass of incident flow molecules
m_mol_mass_p: Mean molar mass of surface molecules. The recommended value is 16.e-3 (kilograms). It must be greater than m_mol_mass, otherwise the theory is not valid (the accommodation coefficient is then set to %nan).
alpha_k is between 2 and 4. Recommended values are: 3.6 (according to COOK) or 3.8 (according to JACCHIA).
Hypothesis:
- Free molecular flow: Kn = lambda / L >> 1 with lambda: mean free path in the free stream and L: typical linear dimension of the body. That occurs for altitudes greater than 130km.
- Maxwellian distribution of molecular velocities in the incident flow.
Constant for the computation of the accommodation coefficient. (1xN or 1x1)
Mean molar mass of incident flow molecules [kg/mol]. (1xN or 1x1)
Mean molar mass of surface molecules [kg/mol]. (1xN or 1x1)
Accommodation coefficient (between 0 and 1). (1xN)
CNES - DCT/SB
1) Cook, G.E., 1965. Satellite drag coefficients. Planet. Space Sci. 13, 929-946.