A Fortran computer code has been developed to simulate the performance of a turbocompound two-stroke diesel engine. This powerplant offers the potential for fuel efficiency combined with high power-to-weight ratio, and is being considered for airborne applications such as helicopters and drone aircraft. The simulation code allows the user to specify engine parameters for the diesel core, the turbocharger (in the form of a performance curve), the bottoming turbine, and the intcrcooler. The program runs in two modes. The user runs the design mode first, in which specification parameters are set and the code sizes the turbomachincry and intercooler. The off-design mode can then be run to see how the resulting engine will perform at off-design values of ambient conditions, fueling rate, and engine speed.The code has been developed to run on an IBM PC. Graphical interface programs allow the user to input parameters on a screen showing the engine schematic, and to display the simulated performance in various graphical formats.