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Oblique Shock Relations

Oblique shocks satisfy the theta-beta-Mach relation for a wedge or local turning angle in supersonic flow.

Theta-Beta-Mach Relation

For upstream Mach number \(M\), shock angle \(\beta\), deflection angle \(\theta\), and \(\gamma\):

\[ \tan\theta = \frac{2\cot\beta\,(M^2\sin^2\beta - 1)}{M^2(\gamma + \cos 2\beta)+2} \]

The normal component is handled using normal-shock relations:

\[ M_{n1} = M\sin\beta \]

Then \(M_{n2}\) is computed from normal-shock equations, and full downstream Mach is:

\[ M_2 = \frac{M_{n2}}{\sin(\beta-\theta)} \]

References

Anderson, J. D. (2003). Modern Compressible Flow: With Historical Perspective, 3rd ed. McGraw-Hill, Chapter 4.