Abstract
Vapor-Particle Separator (VPS) is a new technology developed for characterization of the
volatile fraction of particulate matter in a combustion aerosol population. VPS incorporates a novel
metallic membrane and operates in a cross-flow filtration mode for separation of vapor and solid
(i.e. non-volatile) particles. Demonstration of the VPS technology on aircraft engine-emitted
particles has led to the improvement of the technology and increased confidence on the robustness
of its field performance. In this study, the performance of the VPS was evaluated against the
Particle Measurement Programme (PMP) volatile particle remover (VPR), a standardized device
used in heavy duty diesel engines for separation and characterization of non-volatile particulate
matter. Using tetracontane particles in the laboratory reveals that the VPS performed reasonably
well in removing the volatile species. In the field conditions, a single-mode particle size
distribution was found for emitted particles from a T63 turboshaft engine at both idle and cruise
engine power conditions. Removal of the volatile T63 engine particles by the VPS was consistent
with that of PMP VPR. In tests on an F117 turbofan engine, the size distribution at the idle (4%
rated) engine power condition was found to be bimodal, with the first mode consisting of particles
smaller than 10nm, which are believed to be mostly semi-volatile particles, while the second mode
of larger size was a mixture of semi-volatile and non-volatile particles. The distribution was single
modal at the 33% rated engine power with no secondary mode observed. Overall, for particles
emitted by both engines, the removal efficiency of the VPS appears to surpass that of the PMP
VPR by 8-10%.
