Mathematical modelling of fluid spray curtains to mitigate accidental releases

In this article experimental and theoretical investigations on liquid spray curtains are presented, in the context of absorbing and dispersing accidental releases of chlorine in air. A mathematical model of a two-phase jet is developed to evaluate the entrained air rate in connection with the liquid flow rate. The model was successfully compared by means of replicated wind tunnel experimental runs adopting spray nozzles suitable to create a two-blade barrier. The experimental work demonstrated that it is possible to distinguish two regions in the barrier. One region is dominated by the liquid inertia and is comparable to an airplane jet. The other region is dominated by gravitational effects, and its dimensions do not vary appreciably. An analytical solution to the problem is obtained, taking into account the instantaneous and nonreversible chemical reactions, i.e., chlorine absorption in alkaline solutions, in the case of still air. The developed methodology could be applied to more complex situations, allowing the attainment of a more generalized approach for the design of a curtain given the release parameters, the site layout, and vulnerable target specifications.