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The current emphasis on environment protection by reducing noise pollution has led to stricter noise standards for general aviation aircraft. As a result, there is a growing demand for a computational tool to predict the noise during the design process. A computer program, called ProRAPP, has been developed for the prediction of noise generated by propeller/rotor blades. The acoustic pressure is calculated using a form of Ffowcs Williams-Hawkings equation which is suitable for numerical implementation. For noise predictions, the observer can either move with the propeller/rotor hub or it can be fixed to the ground. Experimental data from both wind tunnel and flight tests are used to validate the numerical results.

Since the recognition of the influence of human activity on climate change due to increasing use of fossil fuel energy, significant efforts are being devoted towards the development and implementation of renewable energy technologies that are harmless to the environment. One of the abundant energy sources is the sun. There are currently two primary ways of harvesting energy from the sun: through photovoltaic (PV) panels and through thermal collectors. With the evolution of unmanned air vehicles (UAV), as well as the growing interest in “Green Aviation,” the interest in investigating the usage of PV solar panels in certain category of aircrafts has increased in the last two decades. In a small UAV or low speed personal transportation aircraft, the wings of the airplane could possibly be covered with photovoltaic panels to harness sun's energy for propulsion.

An analytical/computational method of computing radiated noise from ducted rotor due to inflow distortion and turbulence is presented. Analytical investigations include an appropriate description of sources, the cut-off conditions imposed on the modal propagation of the pressure waves in the annular duct, and reflections at the upstream end of the duct. Far field sound pressure levels at blade passing frequency due to acoustic radiation from a small scale low speed fan are computed. Theoretical productions are in reasonable agreement with experimental measurements.