High-pressure left

This is a classical single-phase shock tube filled with air. The test is available in the folder ./libTests/referenceTestCases/euler/1D/shockTubes/HPLeft/. The corresponding uncommented line in ECOGEN.xml is:

<testCase>./libTests/referenceTestCases/euler/1D/shockTubes/HPLeft/</testCase>
_images/schema.jpg

Fig. 40 Initial condition for single-phase shock tube.

The initial characteristics of the run are:

Characteristic

Value

dimension

1 m

initial mesh size

100

AMR max level

3

diaphragm position

0.4 m

boundary conditions

non-reflecting

final solution time

0.6 ms

solution printing frequency

0.06 ms

precision

2nd order (VanLeer)

Solution of this Riemann problem induces 3 waves:

  • expansion waves propagating in high-pressure chamber,

  • a right-facing shock wave propagating in low-pressure chamber,

  • a contact discontinuity.

These waves are clearly observable on the results:

_images/shockTube.gif

Fig. 41 Shock tube filled with air. Visualization using Paraview software.

This test is also equipped with 3 Eulerian sensors. For example, two sensors are positionned at \(x = 0.6 m\) and \(x= 0.8 m\). They record the following pressures:

_images/sensors.jpg

Fig. 42 Pressure recorded by sensors at \(x = 0.6 m\) (pink) and \(x = 0.8 m\) (green). Visualization using gnuplot software.

The first sensor sees its pressure rising first because of the shock wave. Because this Riemann problem generates a supersonic flow after the shock wave, the tail of the expansion waves is seen by the sensor after 0.5 ms.