A parametric numerical study is conducted for the flow in a converging-diverging nozzle suitable for a lead azide laser. The flow is generated by exploding a lead azide pellet at some standoff distance on the nozzle axis. It is shown that the nozzle presence significantly affects the explosion generated flow field. When the explosive products pass through the nozzle a very clear enhancement in the flow pressure, density and temperature is evident, in comparison with values obtained at the same locations in a similar free expansion flow (no nozzle). The enhancement in flow properties, especially in temperature, is desirable for melting all the small solid lead particles suspended in the explosion products gas flow. A suitable nozzle flow (i.e., a flow having a desirable pressure, density, temperature and velocity) can be obtained by the appropriate choice of the nozzle area ratio and its location (standoff distance) with respect to the explosion center. Changes in the pellet mass, its material density and/or the composition of the explosion products also affect the flow inside the nozzle as described in the text. The gasdynamics of the "nozzle-trapped" flow is performed by using a quasi-one-dimensional high-resolution scheme, including a special boundary condition at the nozzle inlet plane.
|Number of pages
|International Journal of Fluid Mechanics Research
|Published - 1 Jan 1999
ASJC Scopus subject areas
- Mechanical Engineering
- General Physics and Astronomy