The aerodynamic noise of landing gears have been widely studied as an important component of the airframe noise. During take-off and landing, there are doors, cavity and fuselage around the landing gear. The noise caused by these aircraft components will interfere with aerodynamic noise generated by the landing gear itself. Hence, paper proposes an Improved Delayed Detached Eddy Simulation (IDDES) method for the investigation of the flow field around a single fuselage nose landing gear (NLG) model and a fuselage nose landing gear model with doors, cavity and fuselage nose (NLG-DCN) respectively. The difference between the two flow fields were analyzed in detail to better understand the influence of these components around the aircraft’s landing gear, and it was found that there is a serious mixing phenomenon among the separated flow from the front doors, the unstable shear layer falling off the leading edge of the cavity and the wake of the main strut which directly leads to the enhancement of the noise levels. Furthermore, after the noise sound waves are reflected by the doors several times, an interference phenomenon is generated between the doors. This interference may be a reason why the tone excited in the cavity is suppressed.

起落架的空气动力学噪声已被广泛研究为机体噪声的重要组成部分。在起降过程中，起落架周围有门，空腔和机身。这些飞机部件引起的噪音会干扰起落架本身产生的空气动力噪音。因此，本文提出了一种改进的延迟分离涡流模拟（IDDES）方法，用于研究单个机身前起落架（NLG）模型以及带有门，腔和机身前鼻的机身前起落架模型（NLG-DCN）周围的流场） 分别。详细分析了两个流场之间的差异，以更好地了解这些部件对飞机起落架的影响，结果发现，从前门分离出来的气流之间存在严重的混合现象，不稳定的剪切层从型腔的前缘掉落，并且主撑杆的尾流直接导致噪声水平的提高。此外，在噪声声波被门反射多次之后，在门之间产生干扰现象。该干扰可能是抑制空腔中激发的音调的原因。