Refractory metals, e.g., tungsten, are an extraordinary class of materials, known for their exceptional properties including high melting temperatures, thermal conductivity, stiffness and strength. While these materials are desirable for high temperature and extreme environment applications, their limited room temperature ductility makes fabrication and implementation challenging. Additive manufacturing (AM) has many potential advantages, particularly in the processing of refractory metals. However, the process parameters needed to fabricate defect-free parts, as well as the effects of AM processing on material properties, are not fully known. In this work, we will computationally study the effect of laser processing parameters on the solidification behavior of tungsten alloys. Single track melt pools will be modeled using computational fluid dynamics software, FLOW3D, and validated with AM experiments across a range of processing parameters (e.g., laser power, velocity). The results from this work will enable rapid development of AM processing parameters for refractory metals and alloys.