Study of convective flow within a 3D ampule using numerical simulation

To model the convective flow associated with the production of non-linear optics within various gravity regimes a finite element model, using FIDAP, was constructed. This model was used to solve the Navier-Stokes incompressible equations with the Boussinesq approximation in the body force term. The solver was run for two ampule designs, one with a rectangular geometry and the other a trapezoidal geometry. The rectangular case was heated first on the side and then on the top while the trape-zoidal case was only heated on the side. All cases used the fluid and thermodynamic properties of 1,2-dichloroethane. The simulation of the heating effects of the UV laser were accomplished by applying a circular heat flux to the ampule. The results showed that the amount of gravity and heat flux strongly affected the isotherms and velocity field. These effects, for the side heated cases, influenced a much larger region of the ampule than the top heated case. This was primarily due to the geometry of the ampule and the way in which the flow interacted with the surface area. It was further shown that lowering the gravitational acceleration reduced the amount of convection in all cases creating a conduction dominated solution.