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Mach 2 in air: the Report 1135 Table II row, the 10° oblique shock and the Fanno and Rayleigh states
| Tool | Compressible Flow Tables |
| Source | Ames Research Staff (1953). Equations, Tables, and Charts for Compressible Flow. NACA Report 1135, National Advisory Committee for Aeronautics, Washington, DC. Table II (p. 634, row M = 2.00), eqs. 43–51, 80, 93–102, 128–145, 171c; Shapiro, A. H. (1953). The Dynamics and Thermodynamics of Compressible Fluid Flow, Vol. 1. Ronald Press, New York. Chapters 6 and 7 (Fanno and Rayleigh lines). |
| Level | Undergraduate |
Problem
Air (γ = 1.4) flows at Mach 2 with a static pressure of 14.696 psi and a static temperature of 59 °F. Give the isentropic ratios of the stream, the normal-shock ratios, the weak oblique shock on a 10° wedge, the Prandtl-Meyer angle, the Fanno and Rayleigh ratios to the sonic state, and the dimensional state ahead of and behind the normal shock.
Inputs to Enter
- Gas air, γ 1.4 (R 53.35 ft⋅lbf/(lbm⋅°R)); mode Every mode at one Mach number, M_1 2.0, deflection 10°
- Dimensional state on: static pressure 14.696 psi, static temperature 59 °F
Answers
- Isentropic (Table II, M = 2.00): p/p_t 0.1278, ρ/ρ_t 0.2300, T/T_t 0.5556, β 1.732, q/p_t 0.3579, A/A* 1.688, V/a* 1.63299, ν 26.380°, μ 30.00°
- Normal shock: M_2 0.5774, p_2/p_1 4.500, ρ_2/ρ_1 2.667, T_2/T_1 1.688, p_t2/p_t1 0.7209, p_1/p_t2 0.1773 (pitot ratio p_t2/p_1 5.640), Δs/R 0.3273
- Oblique shock, δ = 10° weak: θ = 39.31° (strong 83.70°), M_1 sin θ 1.267, p_2/p_1 1.707, M_2 1.641, p_t2/p_t1 0.9846; δ_max 22.97° at θ 64.67°, sonic limit θ 61.49°
- Fanno: T/T* 0.6667, p/p* 0.4082, p_t/p_t* 1.688, fL*/D 0.3050 (Darcy f; subsonic twin M 0.6573); Rayleigh: T_t/T_t* 0.7934, T/T* 0.5289, p/p* 0.3636, p_t/p_t* 1.503
- State: ρ 0.07648 lb/ft³, a 1,116 ft/s, V 2,233 ft/s, q 41.15 psi, p_t 115.0 psi, T_t 933.6 °R; behind the normal shock p_2 66.13 psi, T_2 875.3 °R, V_2 837.3 ft/s, p_t2 82.89 psi
Notes
The tool's default inputs are this case; press Submit. The isentropic and normal-shock values are the printed row of Report 1135 Table II (read from the page render filed in References/Compressible-Flow/); the oblique-shock, Prandtl-Meyer, Fanno and Rayleigh numbers are reproduced by an independent numpy / scipy implementation (compflow_check.py) and the whole library by test_compressible_flow.php (741 checks, 441 of them table cells).