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Nomenclature

Acronyms

Acronym Meaning
CIRA86 COSPAR International Reference Atmosphere (1986)
LTC Low-Temperature Correction (Sutherland viscosity model)
ODE Ordinary Differential Equation
USSA76 US Standard Atmosphere (1976)

Latin Symbols

Symbol Description Units
\(a\) Speed of sound, \(a = \sqrt{\gamma R T}\) m s⁻¹
\(c_p\) Specific heat at constant pressure J kg⁻¹ K⁻¹
\(c_v\) Specific heat at constant volume J kg⁻¹ K⁻¹
\(g_0\) Standard gravity (9.80665 m s⁻²) m s⁻²
\(h\) Geometric altitude m
\(L\) Reference length m
\(M\) Mach number, \(M = U / a\)
\(p\) Static pressure Pa
\(R\) Specific gas constant, \(R = R_u / \mathcal{M}\) J kg⁻¹ K⁻¹
\(R_u\) Universal gas constant (8314 J kmol⁻¹ K⁻¹) J kmol⁻¹ K⁻¹
\(\mathrm{Re}_1\) Unit Reynolds number, \(\rho U / \mu\) m⁻¹
\(\mathrm{Re}_L\) Reynolds number based on length \(L\)
\(S\) Sutherland constant K
\(T\) Static temperature K
\(U\) Flow velocity m s⁻¹
\(Z\) Compressibility factor (equilibrium air)

Greek Symbols

Symbol Description Units
\(\gamma\) Ratio of specific heats, \(c_p / c_v\)
\(\lambda\) Atmospheric temperature lapse rate K km⁻¹
\(\mathcal{M}\) Molar mass kg kmol⁻¹
\(\mu\) Dynamic viscosity Pa s
\(\rho\) Density kg m⁻³
\(\theta_\text{vib}\) Characteristic vibrational temperature K

Subscripts and Superscripts

Symbol Meaning
\((\cdot)_0\) Stagnation (total) condition
\((\cdot)_b\) Base-layer value (atmosphere layer equations)
\((\cdot)_\text{eff}\) Effective value (real-gas mixture)
\((\cdot)_\text{ref}\) Reference value (Sutherland model)
\((\cdot)_\text{rot}\) Rotational energy mode
\((\cdot)_\text{trans}\) Translational energy mode
\((\cdot)_\text{vib}\) Vibrational energy mode