The thermal, electrical, and fluid flow fields associated with a Siemens Power Generation Inc., Stationary Fuel Cells, flattened tubular high power density (HPD) solid oxide fuel cell (SOFC) were investigated comprehensively in a previous study. The present computational investigation is the subsequent part of an ongoing numerical pursuit at Siemens of an optimized cell geometry, commercialization of SOFC technology being the ultimate objective. A Delta type HPD cell featuring eight air channels was investigated and compared with a flattened tubular HPD cell. The computational models were developed using the commercial computational fluid dynamics software FLUENT 6.2 along with its SOFC user defined routine to model the electrochemical effects. The SOFC model parameters were derived from experimental data. The cathode, the anode, and the interconnection layers of the cell were resolved in the model and all modes of heat transfer, conduction, convection, and radiation were included. The resulting electrical performance and the thermal hydraulic characteristics of the cells for fully reformed natural gas fuel flow (reformed external to the cell) are presented and discussed. It was clear from these studies that the Delta HPD cell has distinct advantages over the flattened HPD cell in terms of system electrical performance as well as power density.