Outdoor noise tests using the DGEN 380 turbofan engine conducted by the Japan Aerospace Exploration Agency

Aircraft engine noise has long been an issue in aviation, and with the expected growth in air travel demand and technical innovations in engines (e.g., ultra-high bypass ratios and shorter nacelles), there will be an increasing demand for high-level noise reduction technologies. In this context, the Japan Aerospace Exploration Agency (JAXA) is engaged in research and development of advanced noise reduction technologies for aircraft engines. The technologies explored to date include innovative acoustic liners and quiet nozzles. To demonstrate these noise reduction technologies under practical conditions, JAXA has conducted outdoor tests using the small turbofan engine DGEN 380 over the past decade. During the tests, the engine was operated outdoors, and various acoustic data (e.g., far-field and in-duct) were measured along with engine data and others. This presentation will outline the overview and results of the outdoor tests conducted to date and share the lessons learned during the tests.