Deprecations

This page explains the motivations behind deprecations introduced by a particular version of the module.

v1.4.0

Deprecated pygasflow.generic.sound_speed in favor of sound_speed() in order to remove duplicates.

v1.3.0

The following is a list of parameter names used by shockwave_solver() and conical_shockwave_solver() which are now deprecated:
- "m1" indicated the upstream Mach number. "mu" should be used instead.
- "mn1" indicated the upstream normal Mach number. "mnu" should be used instead.
- "m2" indicated the downstream Mach number. "md" should be used instead.
- "mn2" indicated the downstream normal Mach number. "mnd" should be used instead.
- "m" indicated the upstream Mach number of a conical shock wave. "mu" should be used instead.
Similarly, if users request a dictionary of results (by setting to_dict=True), the aforementioned replacements are used as keys.

The motivation behind this design choice is to improve code clarity and quality. Suppose for example you are working on a flow through multiple shock system, and you assign a name to the states upstream and downstream of each shock. For example, 1 and 2 represents the upstream and downstream conditions of the first shock wave, A, respectively. 2 and 3 represents the upstream and downstream conditions of the second shock wave, B, and so on. The following situation was very common with the old naming convention:
```
M1 = 3
shockA = shockwave_solver("m1", M1, "theta", 15)
M2 = shockA["m2"]
shockB = shockwave_solver("m1", M2, "theta", 20)
M3 = shockB["m2"]
```
The last two commands are confusing. In particular:
- shockwave_solver("m1", M2...: here we were telling the solver that the upstream Mach number to shockB is M2.
- M3 = shockB["m2"]: here, with "m2" we are retrieving the downstream Mach number of shockB and assigning it to M3.
This quickly become even more confusing as we add more shockwaves, both for people writing the code, as well as to people reading it.

With the new naming convention, the above example becomes:
```
M1 = 3
shockA = shockwave_solver("mu", M1, "theta", 15)
M2 = shockA["md"]
shockB = shockwave_solver("mu", M2, "theta", 20)
M3 = shockB["md"]
```
Here, it is clear that we are specifying M2 to be the upstream Mach number to shockB and that M3 is the downstream Mach number of shockB.
beta_theta_max_for_unit_mach_downstream has been deprecated because it generated confusion: it returned the the shock wave angle, beta, where the downstream Mach number was sonic, and the maximum deflection angle, theta, associated to the user-provided upstream Mach number.

Instead, sonic_point_oblique_shock() should be used, which returns the shock wave angle, beta, and the deflection angle, theta, where the downstream Mach number is sonic.
beta_from_mach_max_theta has been deprecated because, while it also computed the maximum deflection angle, theta_max, it only returned the former. However, it is often useful to know both results.

Hence, detachment_point_oblique_shock() should be used, which returns the shock wave angle, beta, and the maximum deflection angle, theta_max, associated to the detachment point.
beta_theta_c_for_unit_mach_downstream has been deprecated in order to have a consistent function name. Hence, sonic_point_conical_shock() should be used, which returns the shock wave angle, beta, and the half-cone angle, theta_c, where the downstream Mach number is sonic.