The subject of the project is modeling of sound generation and propagation in fluid machinery systems. The major innovative aspects are new and improved noise prediction models with the following important applications: source description for IC-engines, design of low noise fans, minimization of sound transmission and generation in flow ducts, design of compact silencers, design of dissipative silencers for hot gas flow. The industrial products directly linked to the project via the participating industries include: fans, air coolers, IC-engines, ventilation systems, domestic appliances and exhaust mufflers.