AirDyn - An Airwake Dynamoneter. Developing an instrument for measuring the effect of ship airwakes on helicopter operations

驾驶海上直升机到舰船的着陆甲板上可能充满困难和危险。部分原因是能见度下降和着陆区域受限，以及船舶运动和低速着陆质量差。然而，另一个困难的来源是船舶上部建筑上的不稳定气流，即空气尾流。随着直升机旋翼从机库顶部和侧面分离，进入尾流，旋翼的推力和力矩变化很大，使直升机难以控制。这一建议是关于开发一种仪器来测量这种流场对模型直升机的影响。这项研究旨在开发一种新的气流测力仪（AirDyn），能够测量飞机的载荷，包括俯仰和滚转力矩。然后，这些可以与着陆甲板上的速度场测量和利物浦飞行模拟器中的飞行员经验相关联。其目的是使用AirDyn，并把我们的注意力不仅仅放在为什么空气尾流影响直升机稳定性和飞行员工作量的问题上，而是如何修改空气尾流以减轻影响，并可能吸引直升机到其着陆点。

Piloting a maritime helicopter onto a ship's landing deck can be fraught with difficulties and dangers. Part of the reason is the degraded visibility and a confined landing area, as well as the ship motion and poor low-speed landing qualities. However, another source of difficulty is the unsteady airflow over the ship's superstructure, i.e. the airwake. As the helicopter rotor moves into the airwake as it separates from the top and sides of the hangar, the rotor thrust and moments vary significantly making the helicopter difficult to control. This proposal is concerned with developing an instrument that will measure the effect of this flow field on a model helicopter. The research aims to develop a new Airwake Dynamometer (AirDyn) capable of measuring aircraft loads, including pitch and roll moments. These can then be correlated with measurements of the velocity field over the landing deck, and with pilot experience in the Liverpool flight simulator. The intention is to use the AirDyn and turn our attention not just to the problem of why airwakes affect helicopter stability and pilot workload, but how the airwake can be modified to alleviate the effects, and possibly attract the helicopter to its landing spot.