A Fluid Flow Analysis of the Gaseous Impact Test

摘要

The Gaseous Impact Test is simulated using fluid dynamics numerical models. Pressure overshoots observed at Centre de Technologies et d'Expertises are matched by one-dimensional computations. Peak temperatures are evaluated when including irreversible processes. Formation of a temperature gradient within the hot gas plug has been identified and an explanation is provided. The influence of geometrical design parameters is studied. Temperature history requires use of a two-dimensional model for it enables description of vortex-induced mixing as a consequence of the reflected shock bifurcation at the test tube end. A cellular structure is formed in the pressure field. Skin temperature of different wall materials has also been evaluated. Short versus long test tube effects are discussed.