A vehicle-level noise assessment has been performed for the NASA D8 (ND8) concept aircraft in the NASA Advanced Air Transport Technology Project portfolio. The NASA research-level Aircraft Noise Prediction Program was used to predict the noise from each source component on the ND8 to build up a noise estimate for the full aircraft. The propulsion airframe aeroacoustic effects of the ND8 (namely, boundary-layer ingestion, with its influence on fan noise; and the noise shielding, reflection, and diffraction mechanisms of the unconventional airframe) were empirically modeled using experimental data. Far-term noise reduction technology concepts were modeled and added to the noise prediction to evaluate the low-noise potential of the ND8 in the far-term timeframe. Results indicate that the increase in fan noise due to boundary-layer ingestion, as well as the lack of aft shielding, prevents the aircraft from approaching NASA’s noise goals for either the midterm or far term. The aircraft achieves margins to Stage 4 of only 9.4 and 17.3 effective perceived noise in decibels (EPNdB) in the midterm and far-term configurations, respectively, compared with goals of 32–42 EPNdB in the midterm and 42-52 EPNdB in the far term.

已对 NASA 先进航空运输技术项目组合中的 NASA D8 (ND8) 概念飞机进行了车辆级噪声评估。NASA 研究级飞机噪音预测程序用于预测 ND8 上每个源组件的噪音，以建立对整个飞机的噪音估计。ND8 的推进机身气动声学效应（即边界层吸入，及其对风扇噪声的影响；以及非常规机身的噪声屏蔽、反射和衍射机制）使用实验数据进行经验建模。对远期降噪技术概念进行建模并将其添加到噪声预测中，以评估 ND8 在远期时间范围内的低噪声潜力。结果表明，由于边界层摄入导致风扇噪音增加，以及缺乏尾部屏蔽，阻止飞机接近美国宇航局的中期或远期噪音目标。与中期和远期 32-42 EPNdB 和远期 42-52 EPNdB 的目标相比，该飞机在中期和远期配置中分别实现了 9.4 和 17.3 分贝的有效感知噪声 (EPNdB) 的第 4 阶段裕度学期。