Effect of Liquid Compressibility at a Jet Impact on a Wall

Resumo

The liquid compressibility effect during impact of a liquid jet at a speed of 250 m/s on the surface of a solid wall is investigated, depending on the jet shape. The study is conducted by the comparison of the numerical solutions obtained with and without taking into account the liquid compressibility (by the CIP-CUP and BEM methods, respectively). It is shown that the manifestation of the liquid compressibility during impact substantially depends on the jet shape. For example, the neglect of the compressibility in the case of impact of a cylindrical jet with a plane end strongly distorts the impact pattern over a long time. In the case of a cylindrical jet with a hemispherical end, a distorted picture appears only at the short-term initial stage of impact. For a pointed cone-shaped jet with an angle between the cone surface and the wall equal to π/4, the flow patterns obtained with and without allowing for the liquid compressibility are almost identical.