  The transient thermocapillary migration of drops with nontrivial deformation
is studied. The finite difference method is employed to solve the
incompressible Navier-Stokes equations coupled with the energy equation; the
front-tracking method is adopted to track the moving deformable drop interface.
In the hot region, deformations of drops increase with the decrease of
interfacial tensions. In order to indicate the temperature impact on the
interfacial tension, a local capillary number ($Ca_l$) is introduced. It is
found that, when the drop density is smaller/larger than that of the bulk
fluid, the drop velocity decreases/increases with the increase of the drop
deformation.
