ASHRAE标准161《商用飞机内的空气质量》要求使用排气传感器来检测润滑油污染。满足这一要求的一种潜在方法是通过粒子检测。进行了一个由四部分组成的实验计划，以详细描述润滑油污染排气时产生的颗粒特性。该项目的第一部分利用了可编程的空气模拟器。一台往复式压缩机和一根加热管被用来产生代表飞机发动机排放空气的受控温度和压力条件。 将雾化润滑油注入压缩机上游的气流中，并在加热管下游测量颗粒特性。该计划的第二部分和第三部分使用安装在试验台上的涡轮轴发动机，并连接到测功机进行控制负载。将雾化油混合到进气中，并测量排气中产生的颗粒特性。第二部分的压缩机使用轴向和离心压缩级，而第三部分的压缩机使用单离心级。 该项目的第四部分使用了美国空军C-17军用运输机上的发动机。机油被注入压缩机的第一级，发动机排出的空气被转移到一个试验平台，在那里对其进行冷却和取样。颗粒大小分布和浓度通过空气动力颗粒大小和扫描流动性颗粒大小进行测量。总的来说，这些仪器可以测量10纳米到20微米范围内颗粒的浓度和尺寸分布。测量结果表明，在大多数操作条件下，压缩机中的油污染会导致排气中出现非常细的雾滴。 这些液滴通常在10-150纳米范围内。由于污染率很低，许多液滴甚至可能小于10纳米。这项研究表明，用于检测飞机排气中的油污染的传感器的开发应侧重于超微粒检测，而低污染水平的检测可能需要对10纳米及更小的超微粒敏感。引文:2017年冬季会议，内华达州拉斯维加斯，会议论文

ASHRAE Standard 161,Air Quality within Commercial Aircraft, includes a requirement for bleed air sensors to detect contamination fromlubricating oil. One potential approach to meeting this requirement is through particle detection. A four-part experimental program was conducted todevelop a detailed characterization of particles that result when bleed air is contaminated with lubricating oil. The first part of the program utilized ableed air simulator. A reciprocating compressor follow by a heated tube was used to create controlled temperature and pressure conditions representative ofbleed air from an aircraft engine. Aerosolized lubricating oil was injected into the airflow upstream of the compressor and the particulate characteristicswere measured downstream of the heated tube. The second and third parts of the program used turbine shaft engines mounted in a test stand andconnected to a dynamometer for controlled loading. Aerosolized oil was mixed into the inlet air and the resulting particle characteristics in the bleed airwere measured. The compressor for the second part utilized both axial and centrifugal compression stages while the compressor for the third part utilizeda single centrifugal stage. The fourth part of the program utilized an engine on an US Air Force C-17 military transport aircraft. Oil was injected intothe first stage of the compressor and the bleed air from the engine was diverted to a test platform where it was cooled and sampled. Particulate sizedistributions and concentrations were measured with aerodynamic particle sizing and scanning mobility particle sizing. Collectively, these instrumentscould measure concentrations and size distributions for particles ranging from 10 nanometers to 20 microns. The measurements showed that oilcontamination in the compressor will result in a fog of very fine droplets in the bleed air under most operating conditions. Typically these droplets are inthe 10-150 nanometer range. With very low contamination rates, it appears that many of the droplets may be even smaller than 10 nanometers. Thisresearch shows that development of sensors for detecting oil contamination in aircraft bleed air should focus on ultrafine particle detection and sensing oflow contamination levels may require sensitivity to extreme ultrafine particles 10 nanometers and smaller.