Removal of IsentropicVortex and RinglebFlow subclasses in CompressibleFlowSolver and add relevant initial condition to the base class.

Issue/feature addressed

The IsentropicVortex and the RinglebFlow subclasses seems to have been created with the only purpose of providing initial condition/exact solution for specific problem. This seems to be unnecessary and prevent using the implicit Euler solver for those problem.

Proposed solution

• Removal of the IsentropicVortex and RinglebFlow subclasses.
• Add relevant initial condition and/or exact solution to the base class
• Add a new ICTYPE solver info parameter to specify the initial condition

Implementation

Tests

The following test has been added to the CI:

• IsentropicVortex16Implicit_P8.tst

Suggested reviewers

Please suggest any people who would be appropriate to review your code.

Notes

The proposed change will allow the use of larger time-step for the coarse solver of the Parareal algorithm for the IsentropicVortex problem.

Checklist

• Functions and classes, or changes to them, are documented.
• [ ] User guide/documentation is updated.
• Changelog is updated.
• Suitable tests added for new functionality.
• Contributed code is correctly formatted. (See the contributing guidelines).
• [ ] License added to any new files.
• No extraneous files have been added (e.g. compiler output or test data files).