This report deals with the development, validation and application of computational models for premixed combustion, non-premixed combustion, solid-propellant combustion and supersonic combustion at FOI Weapons and Protection during 2004. Combustion is a central area for the development, maintenance and modification of many military systems, such as weapon systems, rockets and air-breathing engines. It is also an area under rapid development with the recent advances in non-intrusive diagnostics and supercomputing. The mathematical modelling of turbulent reacting flow is an important issue in this context since it provides the link between numerical flow simulation and combustion chemistry. As is well known the main difficulty here lies in the combination of complex kinetics and turbulence, which can only be mastered by combining theory, experiments and computations.