Small δ ``Weak Oblique shock''

This interest in this topic is mostly from an academic point of view. It is recommended that this issue be skipped and the time be devoted to other issues. The author is not aware of any single case in which this topic is used in real-world calculations. In fact, after the explicit analytical solution has been provided, studying this topic seems to come at the expense of other more important topics. However, the author admits that as long as there are instructors who examine their students on this issue, it should be covered in this book.

For small deflection angles, $\delta$ , and small normal upstream Mach numbers, $M_1 \sim 1+\epsilon$ ,

$$\tan \theta = { 1 \over \sqrt{{M_1}^2 -1}}$$ (13.63)

... under construction.