Shocktube

Setup:

1. The tube is divided in two regions i.e high pressure and low pressure.
2. High pressure is at 6 bar and low is at 1 bar pressure.
3. Fill the high pressure region with nitrogen and low pressure region with oxygen.
4. Create a event 0.001 seconds to break the diapraram and let the fluids mix.

The following plots explain the shocktube outcomes :

This is the outcomes graph of pressure.we can seee that the pressure is constant at the beginning as the diapharam is still not broken,at 0.001 seconds the pressure drops as the diapharam breaks and the fluids move from higher pressure side to lower pressure side.It takes up again when the fluids have the rebound/bounce-back from the walls of the tube building the pressure up and this goes on till the fluids reach as staedy state.The take off points are the points where the fluid has a rebound/bounce-back.

This plot is of the Temperaure.It is contant till 0.001 as the diapharam is still not broken,it is broken at 0.001 seconds.It drops because mixing of fluids brings down the overall temperature,it rises as it hits the wall of the tube creating a friction and thus increasing the temperature.It cools down till it hits the other end of the tube and rises again; It does that till the fluids reache the steady state.

THe plots of the pressure and temperature are similar because temperature and pressure are directly proportional as per Gay-Lussac\'s Law.

Cell count is the number of elements in the tube participating in the event.At 0.001 seconds when the diapharam breaks and fluids mix the cell count goes up and falls back till then the fluid hits the wall shooting the cell count back up.It stay kind of steady till the bounce-back and the count goes high exponentially as the rebound fluid and the fluid still to rebound collide,Due to this the velocity of the flow decreases and due to this phenomenon the tube is able to achive a steady state after some rebounds.