OPTIMIZING THE GAS FLOW THROUGH THE BREATHING APPARATUS MECHANISMS OF DIVERS WITH COMPUTATIONAL FLUID DYNAMICS

• Main Authors: Tamara STANCIU, Andrei SCUPI, Cătălin FRĂŢILĂ
• Format: Article
• Language: English
• Published: Editura Academiei Oamenilor de Știință din România 2018-06-01
• Series: Annals: Series on engineering sciences (Academy of Romanian Scientists)
• Subjects: breathing apparatus; mechanism; gas flow; Computational Fluid Dynamics
• Online Access: http://aos.ro/wp-content/anale/TVol10Nr1Art.6.pdf

We checked the variation of the gas volume flow in three design versions of the gas inlet in intake mechanism of the second stage pressure regulator by Computational Fluid Dynamics. We made the geometric modeling of three versions. After the meshing of the obtained fluid models, the required flow conditions were set. The mass flow rate, the gas density at the outlet of the pressure reducing mechanism and the fluid velocities were calculated. For the same flowing conditions and the same inhalation depression, we determined the external resistances in three chosen geometric versions of the gas intake mechanism. It can be concluded that the best shape of the inlets in the intake seat in second stage regulator is that of 2nd Version with conical section into the piston. To optimize gas flow through the restrictor, in the design of the breathing apparatus, we recommend that the inlet mechanism geometry be in 1st Version and 2nd Version, with 6 cylindrical slots, but the hole in the piston body to be conical, as in 2nd Version. Using Computational Fluid Dynamics we can run other simulations with different geometrical characteristics until we obtain an optimal shape.