A numerical study of intake ingestion relevant to short take-off and vertical landing aircraft

摘要

Intake ingestion can cause several problems, such as compressor surge and stall, for a short take-off and vertical landing (STOVL) aircraft and is therefore an important phenomenon to be controlled in STOVL aircraft design. A multiblock pressure-correction based RANS solver has been developed at Loughborough University to study the intake ingestion problem. The results have been compared with LDA measurements carried out in a water tunnel. A reasonable prediction of the general flow pattern has been achieved; however, the standard linear k- epsilon model has been shown to produce significant errors in the prediction of some important local details of the flow: the forward penetration of the ground sheet flow, upwash fountain flow and intake suction flow. In the current work, two extra scalar equations, one for the mean scalar and another for scalar variance were solved, and used together with an assumed pdf shape to study the statistics of the instantaneous scalar. Good agreement was obtained with measured instantaneous scalar variations in the impingement and fountain regions, but this deteriorated in the ground vortex leading edge, throwing doubt on the ability of a steady-state RANS approach for accurate intake ingestion prediction.