Introductory concepts and definitions: Thermodynamic systems, fluid properties. Energy, work, heat, power. First law. Cycles. Properties of a pure, simple compressible substance: substances that appear in different phases, ideal gas model. Control volume analysis: conservation of mass and energy. Second law: irreversible and reversible processes, Carnot cycle. Entropy: Clausius inequality, entropy change, entropy balance for closed and open systems, isentropic processes and efficiencies. Gas power systems; Air Standard ,Otto, Diesel, Dual and Brayton cycles.