摘要: A theoretical analysis of the refracted shadows produced bysteady andtime-decaying liquid vortices under uniform illumination from above is givenin this article. An expression for the induced shadow intensity is derivedand found to be a function of the vortex's free surface profile, i.e.,function of the static pressure distribution. The patterns for differentfocusing depth are given and compared with previous visualization resultsfrom the literature. The phenomenon is examined and illustrated as a benchmark case by using both steady and time-decaying algebraic vortex models.However, this study can be extended to check the feasibility of recoveringthe main flow properties by analyzing the luminous image intensity of therefracted patterns. The present analysis is valid only when the swirlvelocity is order of magnitude higher than the meridional flow componentsand the vorticity is concentrated within the core region and of intenseconditions.