For a depth study of the experimental results of the fuel flow inside transparent nozzles made with acrylic (PMMA)

a three dimensional numerical simulation was carried out with the fluid-structure-interaction(FSI) for analyzing the solid deformation and stress distribution of a tested acrylic nozzle. The simulation results show that the deformation and stress of the nozzle mainly occur in the pressure cavity and at the inlet of the orifice. And the maximum stress is at the entrance of the cavity where the nozzle is connected to the rest of the injector by adhesive. The maximum stress is greater than the adhesive force

causing the failure of the transparent nozzle. Then the change of fluid volume with injection pressure and the effect of solid deformation on fluid flow characteristics were also researched. The results show that the solid deformation of the nozzle leads to the delay of fuel cut-off compared to its actual nozzle

and the total fuel mass discharged from the nozzle increases slightly. The solid deformation also leads to a fact that fuel is continually discharged from the transparent nozzle over a long period of time after injection is over

consistent to the experiment results.