Proposing Method for Airframe Noise Prediction Benefitting Indonesian Aircraft Design

This paper describes the proposal for an airframe noise prediction method that can be used in Indonesian aircraft design research and industry. Since the industry is strategic, whether economically or securely, the country should build their own technology in all phases. Noise assessment is one of the sophisticated procedures in designing and manufacturing aircraft. Indonesia has not developed and manufactured engines, therefore airframe noise prediction is a relevant object to study. This method is proposed to be a utility to improve Indonesian aircraft design specifications. Based on the analogy theory of aeroacoustics, the use of Ffowcs Williams and Hawkings (FWH) equation was chosen to represent noise. The noise prediction method was developed by simulating and modeling in OpenFOAM, an open-source software based on the finite volume method. Its reliability has been proven in research and industrial computational fluid dynamics. The proposed method is developed from CFD and is compatible with using a personal computer device. The algorithm based on boundary conditions and hardware specifications has been built. Each step has been designed to support FWH Equation solver uniquely for this study. Computational domains represent the airflow area overrun a solid object. For the reason of far-field radiation, the domain token is 20 times the dimension of the object, and wall functions are applied. The atmosphere condition of low flight level and low to medium subsonic speed is taken to represent various aircraft designs and configurations. The condition represents the existing Indonesian industry of civil and military flying vehicles, and its possibility to develop.