Computational studies of the effect of rotation on convection during protein crystallization

Effect of rotation on nonlinear solutal convection during protein cystallization is modelled and studied computationally under both normal and microgravity conditions. The axis of the externally imposed rotation, which is assumed to be either parallel or antiparallel to the gravity vector, is assumed to be inclined at an angle γ with respect to the axis of the crystal. In addition to the angle γ, the significant parameters are the solutal Grashof number Gr, representing the buoyancy effect and the Taylor number Ta representing the rotational effect. The numerical computations for various values of the parameters and the gravity level indicated non-trivial competing effects, due to buoyancy, centrifugal and Coriolis forces, on the convective flow adjacent to the crystal interface and the associated solute flux. In particular, certain regimes in (Ta,γ )-space were detected where the Sherwood number, representing the convective solute flux, and the convective effects are noticably reduced. These results can provide conditions under which convective transport during the protein crystal growth approaches the diffusion limited transport, which may be desirable for the production of higher quality protein crystals.