Illustrate the generation of shock waves using the Reddy shock tube.

1.b) Illustrate the generation of shock waves using the Reddy shock tube.

Answer:

Reddy’s shock tube

Generation of shock waves using the Reddy shock tube:

A device used to produce shock waves of required strength in the laboratory is called shock tube. It consists of a long simple tube which is separated into two regions (sections) by a meta diaphragm. The regions are driver and driven sections. The metal diaphragm is commonly driven by compressed high pressure driver gas using either a compressor or by detonation of small quantity of explosive. Thus driver side ruptures the diaphragm creating a shock wave which travels into the driven section along the length of the shock tube.

or

Diaphragm and the needle are detached from the compression tube and the piston is moved outwards to fill the compression chamber with ambient air at atmospheric pressure. The diaphragm and the needle are attached to the compression tube. The piston is pushed into the compression chamber so that the air inside is compressed and pressure builds. As the piston moves the pressure increases and finally the diaphragm ruptures resulting in the very high speed flow of the compressed air. Schlieren images of the flow at the exit of the Reddy tube confirm the generation of shock waves. Thus shock waves of mach 1.5 to 2.0 are generated at the tip of the needle.